Neurosciences - Poster Abstracts

Attention deficit hyperactivity disorder (ADHD) is a heterogeneous behavioral disorder characterized by hyperactivity, impulsivity, and inattention, as well as deficits in both working memory (WM) and sense of time. Although animal models cannot fully reflect human psychiatric disorders, they can provide insight into the disorder that cannot be obtained from human studies. The spontaneously hypertensive rat (SHR) is one of the best-studied animal models of ADHD. In comparison to their control, the Wistar-Kyoto (WKY) rat, male SHRs show multiple behavioral phenotypes characteristic of ADHD, including hyperactivity, impulsivity, and poor sustained attention. In addition, there is increasing evidence that SHRs show impairments in learning and memory. The hippocampus has long been known to be a key brain region for learning and memory, and hippocampal lesions or inactivations in rats cause poorer performance in multiple memory tasks, including elapsed time discrimination and spatial WM tasks. Inflammatory signaling is also a critical contributor to memory and cognitive deficits; however, the precise role that cytokines play in the modulation of ADHD behavioral symptoms remains unknown. To investigate this question, we first examined the behavior of SHRs and WKY rats in multiple behavioral tasks: the delayed alternation task, objects in updated locations task, and light dark box task. We used rats of both sexes in an effort to rectify the current sex imbalance in knowledge about ADHD and to directly examine sex as a biological variable. To better understand the impact of inflammatory signaling on memory and anxiety in SHR and WKY rats, animals were sacrificed after behavioral testing and hippocampal samples were collected. We analyzed the levels of several inflammatory cytokines (IL-10, IL-18, IL-1a, IL-1b, IL-4, IL-6 and TNFa) in the dorsal and ventral hippocampus of female and male SHRs and WKY rats. SHRs showed worse memory performance relative to the WKY rats in the memory tasks but no higher signs of anxiety in the light-dark box. Combined, our data are consistent with impairments seen in rats with hippocampal lesions. These results will be discussed in relation to the levels of cytokines in the hippocampus of SHRs and WKY rats and the impact of inflammation on memory and cognition in ADHD.

2: Balaji, Vibha

Biomedical Engineering

Prediction of longitudinal tau aggregation with deep learning

Balaji, Vibha; Song, Tzu-An; Yang, Fan; Jacobs, Heidi; Johnson, Keith; Dutta, Joyita

Alzheimer’s disease (AD) is the most common form of dementia and is commonly associated with the aggregation of two proteins - neurofibrillary tau tangles and intracellular amyloid beta. The Braak stages demonstrating the progression of AD are found to be strongly correlated with the tau aggregation in particular, which is currently recognized as the biomarker closest to the clinical phenotype of AD. Tau tangles follow neuroanatomically stereotypical propagation patterns along the human brain connectome. Beta-amyloid plaques can be toxic when they accumulate between neurons in the brain, and their correlation with AD progression and tau is still being understood. We make use of a graph neural network as our deep learning model that takes in tau and amyloid beta annualized differential standardized uptake value ratio (ADSUVR) across 66 important regions of interest (ROIs) in the brain, from a dataset of 163 subjects positron emission tomography (PET) scans. Our model predicts the tau vector at the follow up scan on the test dataset. We make use of structural connectivity information from diffusion tensor imaging (DTI) in the brain by using regularizers graph total variation (which calculates the weighted net variation between nodes in the tau vector) and physics-based penalty function that uses the Fisher-Kolmogorov-Petrovsky-Pisnukov (Fisher-KPP) reaction diffusion equation (a partial differentiation equation that models growth and population) with a source term to model additional tau generation. We also make use of GNNExplainer, to introduce interpretability and identify the most important subset of nodes and edges in the 66 ROIs that are identified as crucial to the prediction, and subsequently, to the aggregation, of tau protein. We are able to demonstrate that regularizers that make use of the structural connectivity of the brain from DTI imaging show improved performance over not using regularizers for the training loss function. Thus, tau aggregation can be predicted using underlying neurological structural information of the brain. We demonstrate our regularization performance with metrics such as peak signal-to-noise ratio, root mean square error and brain slice plots. With the help of GNNExplainer, we were able to predict the hippocampus and temporal pole to be important seats in the accumulation of tau, which correlates with our knowledge of AD typically beginning in areas related to memory and progressing to other areas of the cerebral cortex.

3: Barnes, Morgan

Psychological and Brain Sciences

The effect of caffeine on working memory performance and sleep quality in ADHD

Hoff, C., Barnes, M., Berlin, A., Kainec, K., Spencer, R.M.C.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that affects people of all ages. Individuals with ADHD in adulthood experience working memory deficits, which can negatively affect social, behavioral, and occupational functioning. In addition, individuals with ADHD experience irregular sleep-wake patterns, specifically exhibiting difficulties with sleep onset and sleep efficiency. This poor sleep quality can result in daytime dysfunction and subsequent worsening of ADHD symptom severity. To mitigate ADHD symptoms, medication is used to regulate neurotransmitter pathways; however, medication can have many undesirable side effects and can be difficult to manage at the transitional ages from childhood into adulthood. Stimulants are one class of medications used to manage ADHD symptoms. We suggest that caffeine, a stimulant drug, can be taken in the evening hours to treat deficits in working memory as well as improve overall sleep quality in individuals with diagnosed, untreated ADHD. The experiment will take place over the course of three weeks. In this time, researchers will collect 3 weeks of actigraphy data using an actigraphy watch, and participants will complete two overnight sessions in the Sleep Monitoring facility at the Institute for Applied Life Sciences on the University of Massachusetts Amherst campus. During each overnight session, participants will take a counterbalanced pill containing either caffeine or placebo. Researchers will use polysomnography to assess measures of sleep quality and sleep architecture during participants overnight sessions. Participants will perform two memory tasks; the N-Back test and a declarative word pairs task both in the evening and following morning. We hypothesize that when participants with ADHD consume caffeine before bed, their working memory performance observed through the N-Back task, as well as sleep quality measured objectively though polysomnography and actigraphy will be improved when compared within-subjects to their placebo condition. **** Chloe Hoff, Annika Berlin, and Morgan Barnes will all be presenting the same poster*****

4: Belculfine, Samantha

Biology

How do Chronic Stress and Alcohol Usage Disorder Damage the Locus coeruleus to Create a Comorbidity for Early Onset Alzheimer’s?

Belculfine, Packer, da Silva, Tenney, Reis, Fitts, Revka, Moorman, Vazey

Alcohol Usage Disorder (AUD) and chronic stress create a vicious cycle that can severely impact the physical and emotional well-being of the affected. We want to study the effects of ongoing drinking and stress in the context of the brain, specifically, the Locus coeruleus (LC) and the stress-related neurotransmitter that it releases, norepinephrine (NE) Our research focused on mimicking the stress and alcohol cycle in mice and understanding the behavioral changes in the animal and the physical changes in the LC. Project-based research also includes using RNAscope to identify the upregulation or downregulation of Adra2a, Adra1B, and cFOS as a result of the damaged LC.

5: Berlin, Annika

Psychological and Brain Sciences

The effect of caffeine on working memory performance and sleep quality in ADHD

Hoff, C., Barnes, M., Berlin, A., Kainec, K., Spencer, R.M.C.

6: Camille, Webb

Biochemistry and molecular biotechnology

Tools to investigate citrullination in ALS

Camille W, Xu Z, Thompson P

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that is characterized by progressive motor neuron loss, muscle wasting, paralysis and ultimately death. 90% of cases are sporadic (sALS), while the remaining 10% are familial (fALS). The hallmark of ALS neuropathologically is aberrant protein aggregation and inclusion formations in neurons leading to eventual degeneration of motor neurons in the brain and spinal cord. Protein Citrullination (PC), a post-translational modification (PTM), and PAD2 expression has been shown to play a fundamental role in ALS protein solubility and is altered dynamically in the spinal cord during disease progression. These citrullinated proteins are shown to accumulate in protein aggregates. The role of PC in ALS is unknown and has the potential to effect countless proteins potentially contributing to ALS pathogenesis. Identifying citrullinated proteins will improve our understanding of the effects of citrullination on their structure and function as well as possibly uncovering novel biomarkers of early-stage ALS. Our lab has developed complimentary methods to investigate and detect citrullinated proteins and identify the modified sites. The approach utilizes three methods that complement each other by producing overlapping results of various scale. The first method involves label-free proteomics with data analysis with Ionfinder. The second method is to enrich samples with citrullinated proteins by performing proteomics with biotin-PG labelling. The last method is to enrich our samples with peptides containing tagged residues at sites of citrullination by performing proteomics with desthiobiotin-PG labelling. All three approaches alone do not give a comprehensive view of the citrullinome, however, together they can identify low and high abundant citrullinated proteins. These methods will create additional exploration into ALS biology to investigate the effects of citrullination on protein function and structure.

7: Christensen, Jennifer

NSB

Exploring age-moderated patterns in vagal control and brain activity in mothers and their capacity to self-regulate.

Christensen, Jennifer D; Deater-Deckard, Kirby D.

Self-regulation in mothers is important given its role in adaptive parenting behavior which is essential to the health and well-being of the mother and child. Effective responding to parenting demands require strong cognitive (e.g., executive function), affective and physiological regulation, evident as general patterns and individual differences in the mother’s capacity to self-regulate. The Neurovisceral Integration model specifies key roles of vagal control of the heart and coordinated frontal-parietal brain activity in self-regulation. However, little is known regarding whether and how these processes change across adult development. To address this gap, we assessed cross-sectional age differences in a diverse sample of mothers (from 27 to 49 years; child was 3-7 years) in the association between respiratory sinus arrhythmia and frontoparietal alpha power coherence (f-p coherence) during rest and challenging executive function tasks. A strong age moderating effect was found: for younger mothers there was a negative association between respiratory sinus arrhythmia and f-p coherence that decreased in size and became nonsignificant among older mothers. With regard to executive function performance, we found that with increasing age, mothers showed distinct patterns of interacting effects of f-p coherence and respiratory sinus arrhythmia in the prediction of executive function : only among older mothers, respiratory sinus arrhythmia and executive function were negatively associated at high levels of f-p coherence, but positively associated at low levels of f-p coherence. These findings further support and extend the Neurovisceral Integration model by elucidating potential developmental mechanisms of cognitive and physiological self-regulation in mothers. The patterns of cardiac regulation and fronto-parietal coordinated brain activity substantiate several aspects of the Neurovisceral Integration model. Furthermore, the very distinct association between f-p coherence and respiratory sinus arrhythmia, and distinct pattern of statistical prediction of executive function, among older versus younger mothers advances understanding of maternal self-regulation development, and its implications for understanding the role of various aspects of self-regulation in the etiology of flexible and adaptive caregiving.

8: Correll, Erika

Biology / Neuroscience and Behavior

The Contribution of 5-HT1A/2A Receptors and GABAergic Neurons of the Pedunculopontine Tegmental Area to Sensorimotor Gating

Correll E; Castellano G; Fenelon K

Sensorimotor gating is a fundamental pre-attentive process defined by the ability of sensory inputs to inhibit motor outputs. When reduced, sensorimotor gating is associated with disturbances in cognition and attention. Typically measured using the translational prepulse inhibition (PPI) of the startle reflex task, sensorimotor gating is affected in patients suffering from a variety of neuropsychiatric disorders including schizophrenia. Currently, the reversal of PPI deficits is routinely tested in disease experimental systems as pre-clinical trials of neurological drug efficacy. Yet, the cellular and circuit-level mechanisms underlying sensorimotor gating remain largely unclear, even under non-pathological conditions, therefore limiting therapeutic advances. Previous electrophysiological studies in rodents demonstrated that giant glutamatergic neurons of the brainstem Caudal Pontine reticular nucleus (PnC) mediate startle. The PnC receives inputs from the pedunculopontine tegmental region (PPTg), a midbrain structure that contains glutamatergic, cholinergic, and GABAergic neurons, and exhibits cytoarchitectural abnormalities in patients with PPI deficits. While general PPTg lesions markedly reduce PPI, how PPTg GABAergic neurons target the PnC startle circuit remains unknown. Additionally, it is unclear how PPTg GABAergic neurons are modulated by serotonin (5-HT) neurotransmission, which contributes to PPI and is affected in diseases with PPI deficits.

Our study aims to determine how PPTg GABAergic neurons inhibit giant PnC neurons during PPI and how serotonin modulates the activity of these PPTg GABAergic neurons. Using vGAT-cre mice (N = 7), we performed tract-tracing, antibody staining, and confocal imaging to visualize how PPTg GABAergic fibers innervate the PnC ex vivo. Within PnC sections, we assessed whether PPTg GABAergic fibers are apposed to Gephyrin, a marker of inhibitory synapses. Then, we used an optogenetic approach to confirm the contribution of PPTg GABAergic neurons to PPI in vivo. The photo-inhibition of PPTg GABAergic neurons reduced PPI by 50%. Finally, we confirmed that PPTg GABAergic neurons express 5-HT1A/2A receptors. Overall, our data show that PPTg GABAergic neurons express 5-HT receptors and form inhibitory connections with PnC neurons. We also provide strong evidence that PPTg GABAergic neurons contribute to PPI, which is critical to our understanding of the theoretical construct of sensorimotor gating.

9: De Anda Gamboa, Cassidy

Department of Psychological and Brain Sciences

Transgenic tagging and tracking of oligodendroglia for spatial and temporal mapping de novo myelination patterns in the mouse brain.

De Anda Gamboa C, Isaacs E., Flores-Bonilla A., Akli S., Richardson HN

Oligodendrocyte progenitor cells (OPCs) are widely distributed throughout the brain. Myelination of neural circuity in the brain depend on several cellular events, beginning with OPCs exiting the cell cycle and differentiating into oligodendrocytes (OLs). After OLs fully mature, they extend their processes and wrap axons, forming lipid-rich myelin sheaths that protect axons and speed up neurotransmission. OPC differentiation occurs more rapidly in white matter, whereas OPCs in the cortex remain in the pre-differentiated state for longer. During adolescence, increases in myelin are associated with the enhancement of cognitive processing and improved behavioral control, yet we have limited insight into the temporal and spatial patterns of how OLs form myelin sheaths from adolescence into early adulthood. Given the importance of myelin dynamics for brain function and cognitive processing, it is important to understand how regulation of myelin affects lifelong circuit function. To assess de novo myelin generation in developing animals, we used the transgenic mouse line NG2-CreERTM: Tau-mGFP that allows us to differentiate between pre-existing myelin and newly formed myelin. Tamoxifen induction allows for green fluorescent protein (mGFP) to be expressed in myelinating OLs and associated myelin segments along axons. By immunolabeling mGFP, we can track and map pre-existing (GFP-) and newly formed myelin (GFP+). An understanding of temporal and spatial OPC differentiation and myelination will be beneficial in understanding the role of myelin in central nervous system circuitry function throughout development and maturation.

10: Deater-Deckard, Kirby

Psychological and Brain Sciences

Do individual differences in pubertal timing and tempo predict differences in inhibitory control development?

Deater-Deckard, Kirby; Individual Differences in Developmental Lab; Virginia Tech Adolescent Brain Study Team; & the Parents and Adolescents Across Cultures Team

There is longstanding interest in human neuroscience and developmental psychology to understand whether and how individual differences in pubertal timing and pacing (i.e., tempo) influence developmental progression of executive functions (i.e., cognitive processes for planning, directing attention, and keeping in memory relevant information in service to a goal). There is clear evidence that earlier timing and more rapid tempo both contribute to increases in risk-taking behaviors and decisions, via modifications of reward systems in brain as well as reward seeking reinforcement in peer social networks. What is less clear is whether similar effects are observed for central executive network functioning and related executive function behavioral performance; results are mixed, and effect sizes are modest when significant. Prior studies have relied on small homogeneous samples and utilized cross-sectional study designs. The current collaborative program of research brings together over 20 behavioral and brain science investigators at UMass Amherst, Virginia Tech, Duke University, and universities in eight other countries (China, Colombia, Italy, Jordan, Kenya, Philippines, Sweden, and Thailand). Preliminary analyses from analysis of two ongoing longitudinal studies (one of which is a consortium of longitudinal studies in nine countries) have utilized longitudinal assessment of puberty from 10-18 years and of inhibitory control (a key indicator of executive function) using reaction time in the Stroop Color-Word Task or Multi-Source Interference Task (MSIT). The Virginia Tech study also collected four annual waves of front-parietal network activity (fMRI) during MSIT. Results across both sets of longitudinal studies so far indicate that even with very heterogeneous and large samples of participants, there are no statistical predictive effects of timing or tempo on individual trajectories of inhibitory control development. Future research will be exploring whether such effects are found in contexts that promote earlier pubertal onset, or when taking into account subgroup differences in peripheral nervous system regulatory processes (e.g., vagal control).

11: Delvey, Cassandra

PBS

Does Additional Training on a Motor Sequence Learning Task Improve Sleep-Dependent Memory Consolidation For Older Adults?

Delvey, C.; Noronha, A.; Hobson, R.; Spencer, R.M.C.

While sleep has been shown to improve memory performance, not all memory domains have demonstrated this effect, particularly in older adults. Prior studies have shown that hippocampal engagement is necessary for sleep to show improved memory consolidation when compared to wake. However, procedural memory, where improvements must be demonstrated rather than recited, is believed to engage other areas, namely the cerebellum, frontal lobes, and striatum, and thus has been inconsistent in exhibiting sleep-related gains. Strong learners, however, are believed to develop an early cortico-hippocampal representation that matures with practice. Using an implicit serial reaction time task, during which participants are not made aware of an underlying sequence of button presses, we tested the hypothesis that additional training in older adults can engage the hippocampus at encoding, and thereby confer a sleep benefit that would not be found after standard training. We will compare the change in performance before and after an interval spent awake to that of an interval spent asleep. Finally, we will determine if additional training in older adults results in an improvement in sleep-dependent memory consolidation when compared to older adults who receive a standard amount of training. We predict that the additional practice will provide an opportunity for greater hippocampal engagement during encoding, thereby increasing the chances of older adults demonstrating sleep-related memory gains on an implicit procedural task.

12: Falcy, Brennan

Neuroscience and Behavior

CB1 receptor KO mice are protected from circadian disruption-induced metabolic outcomes, without major changes to behavior

Falcy, B., Leise, T., Pearson, G., Phillips, D., Karatsoreos, I.

Disruption of the circadian clock can lead to several changes in metabolic phenotypes, including weight gain, elevated plasma triglycerides, and increased hepatic lipid deposition. We have shown that environmental circadian desynchronization (ECD), by housing mice in 20h cycles (10h light - 10h dark), leads to weight gain, higher adiposity, and altered metabolic hormone levels in mice. While classical metabolic hormones certainly contribute to these phenotypes, understanding and treating metabolic disruption will require a well-rounded knowledge of all involved pathways. Endocannabinoid (eCB) signaling can affect metabolism from the cellular to behavioral levels via effects both in the periphery (e.g., liver) as well as centrally in the brain. Interactions between eCBs and circadian rhythms have been documented in humans, where circadian misalignment can lead to increases in eCBs measured in the blood. To explore these phenomena on a more mechanistic level, we determined the effects of global cannabinoid type 1 receptor (CB1r) knockout on the metabolic and behavioral consequences of ECD. We undertook detailed behavioral and metabolic phenotyping in CB1r WT and KO littermate mice of both sexes during baseline 24h and experimental 20h light-dark cycles. We found that in ECD, weight gain was significantly higher in WT male, but not female, mice compared to KO littermates, demonstrating that CB1r KO mice are resistant to the metabolic effects of ECD in a sex-dependent manner. We replicated this in three cohorts, for a total of n=12/sex/genotype. We additionally assessed levels of circulating metabolic hormones including insulin and leptin at different times throughout ECD for WT and CB1r KO mice. We also explored changes in several behaviors including locomotor activity, feeding, and drinking, as well as a detailed examination of changes in the respiratory exchange ratio, all of which was done blind to the groups. We further explored rhythmicity of behaviors to understand if they differed across groups. Presently, the strong effect of genotype on ECD-induced weight gain does not seem to be explained by differences in gross behaviors or how such rhythmic behaviors are organized.

13: Flores Bonilla, Annabelle

Psychological and Brain Sciences

Phenotyping a Subpopulation of Cells in the Amygdala Affected by Alcohol Exposure

Flores-Bonilla A; Lu YL; Silva-Gotay A; Akli S; Senthikumar R; De Oliveira B; Rajvanshi A; Amira N; Richardson HN

A subpopulation of central nucleus of the amygdala (CeA) GABAergic long-range projection neurons co-express the stress peptide corticotropin-releasing factor (CRF) and calcium calmodulin kinase 2 alpha (CAMKIIɑ). These cells project to the ventral tegmental area (VTA) and CRF plays an anti-stress role, as ablating the Crf gene in this population leads to increased behavioral responses to stress. Chronic alcohol exposure and adolescent drinking have both been linked to reduced CRF peptide levels in the CeA. Chronic alcohol has also been shown to potentiate AMPA receptor activity through CaMKIIɑ activation on these cells, which promotes alcohol self-administration in rats. If these alcohol-induced peptidergic changes are specific to this GABA/CAMKIIɑ/CRF population of CeA cells, it may explain the transition to a negative affective state by an increased stress response and exacerbation of problematic drinking. In other words, CRF release may underlie the stress-reducing properties of acute alcohol and it may require higher drinking to reach those stress-reducing levels after adolescent drinking or chronic alcohol. Alternatively, there could be structural changes that interfere with the anti-stress signaling in this neuronal pathway. GABAergic axons have unique myelin characteristics, with greater myelin thickness on these axons compared to excitatory axons in the corpus callosum. In the CeA, downregulation of gene expression associated with myelin and myelinating cells (oligodendroglia) occurs after chronic alcohol. The objective of this project is to begin exploring these two potential mechanisms by examining peptide content changes and evidence of myelin deficits in a single study. The transgenic mouse reporter line (NG2CreERTM:Tau-mGFP) is used to assess myelin wrapping of axons in CAMKIIɑ/CRF cells. We ran an omnibus study with voluntary alcohol binge drinking (or water-drinking controls) during adolescence (n = 16/per group) using the drinking in the dark paradigm using these mice. We are currently processing brains from these animals for immunofluorescent labeling experiments to test predictions of these alternative hypotheses. We will use confocal microscopy to quantify how alcohol impacts the proportion of GAD67+/CAMKIIɑ+ cells that express CRF in the CeA and myelin ensheathment of axons from these cells.

15: Fox, Quinn

Psychological and Brain Sciences

Validating Sleep Staging in 6 Consumer Devices

Hall, B.A. , Thakkar, M. , Caccavaro, J. , Fox, Q. , Kainec, K.A. , Spencer, R.M.C

Consumer-grade devices for self-monitoring sleep stages have rapidly increased in popularity and prevalence. Despite their commercial prevalence, and potential utility to researchers and clinicians, the accuracy of these novel devices remains uninterested. Here we sought to validate the accuracy of sleep staging tracking devices, compared to gold standard sleep staging with polysomnography (PSG). Six consumer devices were used, including the Fitbit Versa 2, Fitbit HR, Oura Ring, Garmin Vivosmart, Withings SleepMat, and Phillips Actiwatch. Overall, most wearable devices were able to accurately detect time asleep and awake, but were less accurate detecting sleep stages. Light and Deep Sleep times were underestimated, while all five devices that measure sleep staging overestimated REM sleep.

16: Fu, Chen

umass med MaSP

Spatial transcriptomics pipeline in SCOPE

Fu C.; Duranlaforet V.; Huang C.; Schafer D.; Baer C.

Spatial transcriptomics is a promising direction for bioinformatic analysis of tissue/cells. It combines the merits of single cell RNASeq and high-resolution microscopy. In contrast to traditional single cell RNASeq, which provides expression profiles of thousands of single cells, spatial transcriptomic data also includes the spatial localization of each cell. This technological revolution opened the path to elucidate the mechanisms of cell-cell interaction in molecular level.

Sanderson Center for Optical Experimentation (SCOPE) was founded in 2017 and hosts more than 16 highly advanced microscopes. Two spatial transcriptomics pipelines are currently provided in SCOPE: MERFISH (Multiplexed Error-Robust Fluorescence in situ Hybridization) from Vizgen (https://vizgen.com/) and GeoMx DSP from Nanostring (https://nanostring.com/products/geomx-digital-spatial-profiler). The former provides transcription profile of up to 500 genes at sub-cellular resolution while the later provides whole transcriptome profile for regions of interest (with multicellular level resolution).

Since the first transcriptomics pipeline (MERFISH alpha) established in SCOPE in 2019, more than 150 samples from >10 laboratories have been processed and imaged. Some of these data were published with Dr. Paul Greer’s lab in Nature Neuroscience (https://www.nature.com/articles/s41593-022-01030-8) and with Dr. Dorothy Schafer’s lab (https://www.jneurosci.org/content/42/32/6171). And multiple manuscripts are in preparation.

SCOPE provides services from sample preparation to data analysis. We welcome any inquires to (SCOPE@umassmed.edu). Also, we will be glad to collaborate with laboratories interested in spatial transcriptomics and light microscopy on research and funding applications. The SCOPE Vizgen (MERFISH-Alpha) instrument was funded by a grant from the Massachusetts Life Sciences Center.

17: Guzmán Clavel, Luis

Neuroscience Program, Biology Department, Amherst College. 2. The Solomon H. Snyder Deparment of Neuroscience, The JHU School of Medicine

Nectins regulate neocortical layer II/III neurite branching

Guzmán Clavel LE, Sudarsanam S, Kolodkin AL, P.h.D.

Neural circuits are the basis of all brain functions. Neurons form pinpoint connections with the right synaptic partners and create perfectly crafted circuits that make the complex and diverse functionality of the brain possible. Improper connectivity patterns between neurons often give rise to pathologies, making understanding the processes that regulate connectivity a critical task. The neocortex is a key area of the brain’s cortex with vast interconnectivity between its multiple functional areas. These functional regions are composed of six distinct layers, which form layer-specific connections and also innervate distinct areas of the brain. For instance, layer II/III neurons have specifically regulated axon collateral patterns, branching out in layers II/III but not in layer IV, both ipsi- and contralaterally. While the cell dynamics of this process have been described, the molecular mechanisms underlying the layer-specific axon branching remain elusive. Here, we present the first known extracellular regulator of this process in the Nectin-family protein Nectin-3. Nectins are immunoglobulin-like cell adhesion molecules that are critical for the development of adhesive interactions and recruitment of cadherins to synaptic and puncta-adherens junctions. Through temporally-controlled in utero electroporation and the use of the sparse-labeling technique Supernova, we describe the effect that overexpression and knockdown of Nectin-3 have on layer-specific neurite branching of somatosensory layer II/III neurons. Both cell-specific and population Nectin-3 KD caused a significant number of branches innervating layer IV when compared to controls. Surprisingly, Nectin-3 OE led to a similar increase in layer IV branches, albeit with additional alterations to dendrite orientation. Increases in filopodia-like structures throughout the axon were also observed. Nectin signaling could signify the first layer-specific branch inhibiting cue that acts as a modulator of axonal collateral growth, opening the possibility of studying the intracellular mechanisms of such a pathway.

18: Hoff, Chloe

Biology

The effect of caffeine on working memory performance and sleep quality in ADHD

Hoff, C., Barnes, M., Berlin, A., Kainec, K., Spencer, R.M.C.

19: Huang, Wanyun

Biology

Spatiotemporal identification of amygdala neurons active during sensorimotor gating

Wanyun Huang; Karine Fenelon

Prepulse inhibition (PPI) of the acoustic startle reflex refers to the inhibition of a startle response when a weak stimulus (“prepulse”) is presented prior to an alarming stimulus (“pulse”). PPI is a standard operational measure of sensorimotor gating. As a hallmark of schizophrenia, PPI impairments are also found in other neuropsychiatric disorders and are associated with cognitive overload and attention deficits (Braff et al., 2001). Therapeutic advances are limited by the gap in our knowledge of the PPI underlying neuronal circuitry. In fact, the currently used dopaminergic-based antipsychotics have shown inconsistent effects on PPI in affected individuals (Frau et al., 2014).

Previous stimulation and electrophysiological studies showed that giant glutamatergic neurons located in the brainstem Caudal Pontine reticular nucleus (PnC) mediate the startle response (Lengenhöhl and Friauf, 1992). The PnC neuronal population includes both giant glutamatergic neurons and glycinergic neurons (Koch and Friauf, 1995; Rampon et al., 1996; Zeilhofer et al., 2005) which receive various glutamatergic inputs. We recently showed that the central nucleus of the amygdala (CeA) contributes to PPI by sending glutamatergic inputs to PnC glycinergic neurons (Cano et al., 2021). But the CeA neurons active during PPI remain unknown.

To answer this question, we used Cal-light, a calcium-dependent and blue light-sensitive method that enables the identification and manipulation of active neurons during a given behavior (Lee et al., 2017). By delivering Cal-light viral components to the CeA of wildtype mice (n = 3), we were able to identify a specific subset of CeA neurons (accounting for 13.1% of total neurons in the CeA) active during PPI, because upon calcium entry and in the presence of blue light, these neurons became green fluorescent. Since Cal-light targeted CeA neurons also expressed the inhibitory optogenetic tool Halorhodopsin sensitive to yellow light, photo-inhibiting these neurons with yellow light yielded a 25.1-52.8% reduction in PPI level measured at various interstimulus intervals between the prepulse and the pulse. Overall, our results confirm that CeA-PnC synapses contribute to PPI and Cal-light allows us to identify the CeA neurons involved, with high spatiotemporal resolution. Our findings provide critical insights toward identifying potential therapeutic targets for diseases associated with PPI deficits.

20: Isaacs, Emily

Department of Psychology and Brain Sciences

Transgenic tagging and tracking of oligodendroglia for spatial and temporal mapping de novo myelination patterns in the mouse brain.

De Anda Gamboa C; Isaacs E; Flores-Bonilla A; Akli S; Richardson H

21: Karuvally, Arjun

College of Information and Computer Sciences

Energy-based General Sequential Episodic Memory Networks

Karuvally Arjun; Sejnowski J. Terry; Siegelmann T. Hava

The state of the art in energy-based memory models is the General Associative Memory Model (GAMM), which has a time-constant state-dependant energy surface that leads the output dynamics to fixed points, retrieving single memories from a collection of preloaded memories. We introduce a new class of General Sequential Episodic Memory Models (GSEMM) that, in the adiabatic limit, exhibit a temporally changing energy landscape, leading to a series of meta-stable points that are sequential episodic memories. The dynamic energy surface is enabled by newly introduced asymmetric synapses with signal propagation delays in the network's hidden layer. We study the dynamical properties of Dense Sequential Episodic Memory from the GSEMM class that has exponential memories in the number of neurons for enhanced storage and retrieval. We introduce a learning rule for the synapses based on the energy minimization principle and show its effectiveness in online learning single memories and their sequential relationships. This rule is analogous to the known Hebbian and Spike Timing Dependent Plasticity (STDP) biological learning rules, suggesting the utility of energy minimization on learning and memory. While further studies will show the utility in better understanding brain mechanisms, our work is immediately available to advance AI and machine learning by bridging memory models with learning and moving the field from single to sequential episodic memories.

23: Liao, Zhixin

Neuroscience

Gpr37a Regulates Retinal Stratification and Müller Glial Maturation in Zebrafish

Wang Y; Liao Z; Pathak N; Owino S

G Protein-Coupled Receptor 37 (GPR37) is an orphan transmembrane receptor highly expressed in oligodendrocytes and retinal Müller glia (Roesch et al., 2008; Karlsson et al., 2021). Although previous studies have established a role for GPR37 in oligodendrocyte maturation and protection against demyelination (Yang et al., 2016), its role in Müller glia remains largely unknown. However, little is known about Gpr37 in zebrafish and its genetic expression has not yet been characterized.

This project characterized the expression of Gpr37 mRNA in zebrafish early embryonic development with hybridization chain reaction RNA-in situ hybridization (HCR RNA-FISH) and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). At 1 day post fertilization (dpf), gpr37a is detected in the midbrain, hindbrain, and retina. Starting from 3 dpf, gpr37a expression diminishes in the brain and is only detected in the inner nuclear layer (INL) and ciliary marginal zone (CMZ) of the retina, colocalizing with the Müller cell marker gfap-GFP. The paralog of gpr37a, gp37b, has not been found in Müller glia.

Recent research has discovered that zebrafish Müller glia can reprogram into progenitor cells upon injury, and migrate to the site of injury to regenerate damaged neurons (Powell et al., 2016), making zebrafish an exciting new model for studying regeneration. Since GPR37 has been known to mediate glial injury response in mice (McCrary et al., 2019), gpr37a’s role in zebrafish Müller glia was studied in focus. Through morpholino knockdown, we observed delayed retinal stratification as well as underdeveloped Müller glia processes, indicating that the knockdown of gpr37a impaired retinal cell migration and Müller glia maturation during development.

Future experiments may be designed to determine the role of gpr37a in retinal regeneration in response to injury using the knockdown model. Gpr37’s potential role in Müller cell-mediated injury repair may provide novel insight into regenerative therapies.

24: Lin, Hongtong

Smith College

Measures from the peripheral skin clock with and without the central clock

Lin H., Lo C., Nie Z., Harrington ME

Skin offers a peripheral circadian clock that is directly photosensitive. Prior studies demonstrate that this tissue can maintain a light-entrained rhythm even when the SCN-driven locomotor activity is free-running (Buhr, Curr Biol 2019). To measure the circadian rhythms of skin cells and the locomotor activity of C57BL/6 mice, we crossed the mice carrying human K14 promoter-driven Cre recombinase (K14-Cre; JAX 018964) with the rhythmic D-site albumin promoter binding protein knock-in (DbpKI/+) mice (JAX 036977; breeders generously supplied by Dr. D. Weaver, UMass Medical School). This allowed Dbp-driven luciferase to be expressed mainly in the epidermal cells. We first entrained mice to 12:12 LD and then housed them in DD with synthetic luciferin CycLuc1 (MedChemExpress) in the drinking water. Photons emitted were detected and quantified by Lumicycle in vivo recording units (Actimetrics, Wilmette IL) using methods detailed in Martin-Burgos et al. (JBR, 2022). Next, we performed SCN-lesion surgeries to determine if the skin cells would persist their rhythmicity without the SCN in freely-moving mice. During the 4 to 7-day surgery recovery, the mice were exposed to 12:12 LD with both UVA and LED light. After the recovery, the mice were housed in DD with CycLuc1 in drinking water. With the help of Lumicycle, we observed robust circadian rhythms of K14-expressing cells in behaviorally arrhythmic mice, but with dampened amplitude. Further research will focus on validating the possibility of the peripheral clock responding to light or other environmental cues.

Grant: NIGMS R15GM126545

25: Malekzadeh, Masoud

Biomedical Engineering

Sleep Staging using instantaneous heart rate

Masoud Malekzadeh, TzuAn Song, Joyita dutta

Sleep quality and duration play an essential role in human health. Sleep deprivation and anomalies in sleep architecture have been related to various chronic health issues, including sleep apnea, diabetes, stroke, brain injury, Parkinson’s disease, depression, and Alzheimer’s disease. Growing bodies of research suggest that deep sleep may help the brain to wash away Alzheimer’s-related toxins. As a result, it is very important to detect the sleep hypnogram and its macro architecture features accurately. Polysomnography (PSG) is the gold standard for measuring sleep quality and disorders and requires a multimodal acquisition of various signals like an electroencephalogram (EEG), electrooculogram (EOG), electromyogram (EMG), and an electrocardiogram (ECG). Although the PSG study is the gold standard for determining the sleep stages, it has other disadvantages as well. Laboratory PSG studies can cause significant disruption to the patient’s sleep and fail to capture a patient’s normal sleep patterns.

Heart rate variability has been shown to be a surrogate signal due to its modulation by sleep and the autonomic nervous system (ANS). Through its central and peripheral circuits, the ANS controls vital involuntary body functions. The ANS and sleep are closely related along anatomical, physiological, and neurochemical lines. The central autonomic network (CAN) orchestrates the sympathetic and parasympathetic branches of the autonomic nervous system through ascending and descending connections from the hypothalamic-limbic region to the nucleus tractus solitarius (NTS) in the medulla. Sleep-promoting neurons, which are scattered in the vicinity of the central autonomic network (CAN) and its connections along with cholinergic REM-on and catecholaminergic REM-off cells in the ponto-mesencephalic junction and pons, control non-rapid eye movement (NREM) and rapid eye movement (REM) sleep cycles. The parasympathetic component of the autonomic system increases with sleep depth (i.e., N1, N2, N3), while the sympathetic component is related to awakenings or REM sleep.

HRV can be directly calculated from R-R intervals, but we are developing deep-learning algorithms for automatic sleep staging that can extract other features besides HRV from instantaneous heart rates. Our method has shown promising accuracy proven to predict the clinical metrics e.g., deep sleep duration using heart rate with good approximation compared to sleep monitoring devices like the Dreem headband, which uses EEG with accelerometer data.

26: Nie, Zhen

Smith College Neuroscience

Chocolate as breakfast accelerates locomotor activity and liver gene expression in response to photic phase advance

Zhen Nie, Mary Harrington

Exposure to jetlag or shiftwork can lead to internal misalignment between the central pacemaker and peripheral organs. Such internal desynchrony can potentially lead to health problems, such as cardiovascular disease. A previous study has shown that palatable food like chocolate can accelerate locomotor activity re-entrainment to a 6h shift in rats (Escobar et al., 2019). Such evidence suggests that chocolate might be able to also reduce internal misalignment between the central pacemaker and peripheral oscillator. In this case, we are particularly interested in the liver as it is a major metabolic organ. In the first experiment, mice were randomly divided into the control and chocolate groups and both were fed ad libitum. The mice in the chocolate group were given chocolate 5 minutes before their active phase after a 6-hour shift (n = 10). The results reveal that chocolate significantly accelerates locomotor activity reset. Notably, female mice treated with chocolate re-entrained significantly faster than male mice. In the second experiment, female and male Alb-Cre;DbpKI/+ mice were utilized, where their livers can rhythmically express Dbp-driven luciferase. Liver bioluminescence signal was emitted when mice were supplied with substrate Luciferin via drinking. Locomotor activity and bioluminescence signal were measured simultaneously in the LumiCycle Invivo recording unit (Actimetrics). Because the photomultiplier tube in the Lumicycle Invivo recording unit cannot detect bioluminescence signals under light, mice were housed in skeleton photoperiod (LDLDLDLD 1:1:1:6:1:1:1:12) to achieve maximum signal detection. Similarly, mice were randomly divided into the control and chocolate groups, and the mice in the chocolate group were administered chocolate 5 minutes before their active phase after a 6-hour shift of advancement (n = 10). Results indicated that chocolate can accelerate both locomotor activity and liver re-entrainment.

28: Niroula, Pratima

Neuroscience

Effects of Jetlag on Skin Healing

Niroula P; Buhr E; Harrington M

My project investigates the effects of chronic jetlag on skin healing in mice. Given the increase in the number of people traveling outside of time zones or switching between shifts at work, the issue of how our physiology reacts to these disruptions is very relevant to public health.

I used four different groups of mice in my experiment. Two groups of wildtype mice in control and jetlag conditions, and another two groups of Opn5 knockout mice in control and jetlag conditions. Opn5 is a neuropsin that has been shown to mediate local light-dependent induction of circadian clock genes and circadian photoentrainment in rodent skin (Diaz et al. 2020). Recently, it was shown that Opn5 knockout mice have impaired healing in the cornea as opposed to jetlag mice (Buhr et al. 2019).

To induce jetlag, I shifted the jetlag group’s Light/Dark schedule from 8am – 8pm to 8pm – 8am for a week. At the end of the week, I reversed all groups back to their normal schedule of 8am – 8pm for another week. I then performed biopsy punches on dorsal skin and ear skin for all mice. On day 2 of the biopsy punches, I collected tissues from half of the mice in all groups. I collected tissues from the remaining half of the mice on day 6. I then sectioned these tissues at a thickness of 20um. I did immunofluorescence staining on these sections to stain for markers of interest. I stained the ear tissues with Vimentin antibody, a fibroblast marker, and the dorsal skin tissue with K17 antibody, a marker for keratocytes in the epithelium. I also stained all the tissues with DAPI to assess gross cell morphology and the numbers of nuclei. With confocal microscopy, I imaged the sections and am currently processing the images with ImageJ software to analyze differences in healing.

Díaz NM, Lang RA, Van Gelder RN, Buhr ED (2020) Wounding Induces Facultative Opn5-Dependent Circadian Photoreception in the Murine Cornea. Invest Ophthalmol Vis Sci 61:37.

Buhr ED, Vemaraju S, Diaz N, Lang RA, Van Gelder RN (2019) Neuropsin (OPN5) Mediates Local Light-Dependent Induction of Circadian Clock Genes and Circadian Photoentrainment in Exposed Murine Skin. Current Biology 29:3478-3487.e4.

29: Nulman, Jonathan

BMB

Characterizing the LRP1 Sheddome, a Driver of Neuroinflammation

Nulman, J.; Rauch, JN

The formation and spread of pathogenic aggregates of the protein tau has been linked to Alzheimer’s Disease (AD) and other neurodegenerative diseases. Recent evidence suggests that the chronic neuroinflammation seen in AD patients can further tau aggregation and pathology, which then amplifies neuroinflammation in a feed-forward mechanism (Pascoal et al., 2021). The low-density lipoprotein receptor-related protein 1 (LRP1) plays a central role in tau uptake and spread (Rauch et al., 2020). LRP1 has more than eighty known ligands, some of which have been shown to cause the proteolytic shedding of its ectodomain. This results in a soluble moiety that is potently pro-inflammatory (Brifault et al., 2017). This suggests a possible mechanism for the tau-neuroinflammation feedback loop. However, the shedding-inducing capabilities of many LRP1 ligands, including tau, remain unknown. The LRP1 sheddome thus represents a significant gap in knowledge as the tau-LRP1 interaction may be an enticing therapeutic target for AD. Here, I present a novel luminescence-based approach to characterize the shedding-inducing capabilities of LRP1’s many ligands.

30: Pearson, Gregory

NSB

Neuroimmune activation of the olfactory bulb is regulated by time of day

Pearson G; Falcy B; Wang J; Akli S; Karatsoreos I

Background: Given its proximity to the nasal cavity, the olfactory bulb (OB) must generate robust neuroimmune responses to defend against neurotropic pathogens. The circadian clock primes cells and tissues to anticipate physiologically relevant environmental changes. We hypothesized that daily changes in OB neuroinflammatory state would differentially "prime” responses to an intranasal inflammatory challenge. Aim 1 probed the OB’s neuroinflammatory transcriptional profile throughout the day. Aim 2 investigated how time of day of an intranasal inflammatory challenge influences the cellular responses within the OB. Methods: For Aim 1, OBs were isolated from male C57BL/6N mice at 8 times of day (n = 3 mice/time, N = 24, 11-13 weeks old). Transcriptional profiles of OBs were assessed using a NanoString Murine nCounter Neuroinflammation Panel. Gene expression data were normalized to housekeeping genes using Rosalind software and assessed for rhythmic expression using JTK cycle analysis. For Aim 2, we intranasally challenged male C57BL/6N mice (n = 4 mice/time/treatment, N = 24, 15-18 weeks old) at different times of day with poly(I:C) (dosages of 10 g or 20 g, 10 L per nare) or a vehicle control and then measured cellular responses within the OB at 24-hours post-inoculation using imaging flow cytometry. Intranasal challenge experiments were completed over three independent experiments, with each experiment consisting of a single treatment at two times of day. Compensation and fluorescence minus one (FMO) controls were used for compensating flow cytometry data and confirming positive populations, respectively. To assess the effect of time of day and treatment a two-way ANOVA was used. Results: We identified 154/757 neuroinflammatory-related genes (20%) that were rhythmically expressed (JTK cycle analysis, adj. p < 0.05) in the OB under baseline conditions. These rhythmically-expressed genes were enriched in the type I interferon signaling pathway with elevated expression at the beginning of the active phase. We also observed rhythmic expression of genes involved in microglia function including several involved in sensing changes in brain state. Following intranasal challenge with poly(I:C), we observed enhanced ability by OB microglia (CD11b+, CD45low, P2RY12+ cells) to fluctuate the surface expression of CD11b at ZT12 compared to ZT0. Conclusion: The circadian clock may prime the OB’s response to intranasal inflammatory stimuli differently depending on time of day of exposure, providing a potential gating mechanism underlying differential susceptibility to pathogen exposure via the nasal route, including neurotrophic pathogens.

31: Perk, Chris

PBS

Identification of afferent frontal pole projections and synaptic contacts in the rat using SynaptoTag virus

Perk, C. G. and Moorman, D. E.

The prefrontal cortex regulates executive function, which includes the ability to withhold behavior, and is disrupted in conditions such as attention-deficit hyperactivity disorder, drug and alcohol abuse, and other manifestations of impulstivity/compulsivity. However, the extent to which the most rostral part of frontal cortex, the frontal pole (FP), is involved in such executive functions has not been characterised, particularly in the rodent. In fact, it is unclear whether the frontal pole is an anatomical entity unto itself or constitutes extensions of more caudal frontal areas such as the frontal association area (FrA) or orbitofrontal cortex. To characterize potentially divergent FP circuits, we injected a small volume (100 nl) of the circuit-tracing SynaptoTag AAV virus (Xu and Südhof, 2013) into the rostral (AP > 5.2mm, all injection sites) frontal association area (FrA, n=3, ML: 1.4mm, DV: 0.5mm), lateral orbital cortex (LO, n = 4, ML: 2.0mm, DV: -1.8mm ), or ventral/medial orbital cortex (VO/MO, n = 4, ML: 0.5mm, DV: -2.5mm) of Wistar rats. Animals were perfused 6 weeks post-injection and their brains removed for subsequent sectioning and immunohistochemical processing, before the distribution of mCherry-positive fibres and GFP-positive presynaptic puncta in each brain was assessed. Beyond injection sites, we found all three regions projected most strongly to dorsal striatum and thalamus, both ipsi- and contralaterally. However, each FP area innervated distinct subregions within these structures, particularly in striatum, where FrA was found to innervate lateral striatum, while LO and MO/VO projected to central and medial striatum, respectively. In thalamus, VO/MO intensely innervated most of the mediodorsal thalamic nucleus (MDT), whereas FrA and LO synapses were restricted to lateral MDT, as well as motor thalamus regions. We also detected synapses associated with a projection from FrA to cingulate cortex, and from FrA and MO/VO to amygdala. These data indicate that separate FP subregions could differentially control behavior, including executive functions such as response inhibition, a hypothesis that is currently being explored in our lab.

32: Ramirez, Desmond

University of Massachusetts Amherst

Neuronal cell type mapping in the ring and rhinophore ganglia of a gastropod mollusc using single cell transcriptomics

Ramirez, M.D., Bui, T.N., Katz, P.S.

Although neuroscience research on gastropod molluscs has provided important insights into the neural circuit function, it has generally been limited to the large identifiable neurons in the central ring ganglia (CRG). Here we take a transcriptomics approach to map neurons from ganglia in the nudibranch, Berghia stephanieae. The CRG (cerebropleural, pedal, and buccal ganglia) were separately dissected from the relatively unstudied rhinophore ganglion (RhG). Neurons were dissociated and their RNA sequenced using the 10X Genomics and Illumina platforms. Transcriptomes from about 2000 cells were recovered and subjected to standard clustering gene expression analyses. Neuronal and non-neuronal cell types were distinguished based on gene expression. Two clusters were composed almost exclusively of RhG neurons, however RhG neurons were also found throughout other clusters. Some clusters represented expected cell types such as mechanosensory afferents, differentially expressing Brn3, Drgx, Islet, and VGlut, and somatic efferents, expressing Mnx1, Lhx3/4, and ChAT. Other clusters included putative neuroblasts, expressing genes such as Sox2 and Sox6, Scratch1, LMO4, and neurogenin. Neurons expressing particular sets of genes were mapped by multiplexing fluorescence in-situ hybridization chain reaction. Neurotransmitter and neuropeptide classes were identified, uncovering general rules of neurotransmitter phenotypes, such as cholinergic neurons do not express particular peptides. Some genes were found to have widespread expression including CCWamide; others, including the transcription factor Six6, defined particular zones of neurons or specific ganglia. Previously unannotated genes were expressed in specific neuron types. The results provide insight in the organization and identity of gastropod neurons and provide the basis for future large-scale neural research on Berghia.

33: Rodberg, Ellen

Biology

Sex differences in adrenergic α1 regulation of reinforcement behavior

Rodberg E; Yu S; Vazey E

Humans and animals need to exhibit appropriate behavioral responses to environmental cues, both to obtain resources and avoid threats. Appropriate behavioral responses are mediated in part by brainwide norepinephrine (NE) levels and locus coeruleus (LC) neural activity. LC-NE has been shown to have an inverted-U shaped effect on task performance where performance decreases when NE levels are outside an optimal range, either too high or too low. In addition to the relationship between NE and behavior, previous research has identified sex differences in the size, structure, and stress responsivity of LC. Independently, sex-differences have been found in positive and negative reinforcement learning.

To probe the role of α1 adrenergic signaling on reinforcement behavior, we administered an α1 agonist (cirazoline; low dose 0.1mg/kg, high dose 0.3mg/kg) and antagonist (prazosin; low dose 0.5mg/kg, high dose 1mg/kg) in adult Sprague Dawley rats (n=22, 12 female and 10 male) during an active avoidance and reward seeking task. During this task, rats learned to press a lever in response to a cue for a liquid sucrose reward (reward seeking trials) and press an opposing lever after a different cue to avoid a foot shock (0.25mA, 500ms; active avoidance trials).

We found that the ability to appropriately respond to positive and negative reinforcement cues is sensitive to α1 adrenergic signaling in a sex-specific manner. On active avoidance trials, high doses of both α1 agonists and antagonists decreased accuracy in males whereas females were only affected by α1 agonists. This decreased accuracy was driven by increased omitted responses in both males and females. Reward seeking trials were less sensitive to α1 manipulation and accuracy only decreased after high doses of cirazoline in males. Overall, reinforcement behavior in males, particularly to cues predicting a potential threat, was sensitive to α1 manipulation and followed a Yerkes-Dodson relationship as predicted for LC-NE. Females were more resilient to α1 manipulations during this task which may be due to different behavioral strategies or NE receptor distribution. Results from this study indicate that cirazoline and prazosin, by increasing and decreasing α1 noradrenergic signaling respectively, can impair reinforcement behavior and the degree to which α1 modulation impacts behavior differs based on sex.

34: Sant, Harshada

Biology

A connectomics approach to an enigmatic ganglion in a gastropod mollusc

SANT H. H. , DRESCHER B. D. , MEIROVITCH Y. ,SCHALEK R. , WU Y. , LICHTMAN J., KATZ P. S.

The central nervous system (CNS) of nudibranchs and other gastropod molluscs are well known for their large identifiable neurons. In addition, there are peripheral ganglia that contain much smaller neurons of unknown identity and function. Here, we took a connectomics approach to determine the structural organization of neurons in the rhinophore ganglion (RhG), which sits at the base of the rhinophore, the chemosensory appendage, in the nudibranch, Berghia stephanieae. Based on its position, the RhG should be analogous to the antennal lobe of insects or the olfactory bulb of vertebrates. However, the neuronal architecture and connectivity of the RhG is unknown. To address this, we serially sectioned an entire RhG at 33 nm thickness and completed imaging each of the 2175 sections at 4x4 nm lateral resolution. We determined that the RhG contains around 9000 neuronal somata, which is almost twice as many neurons as the rest of the brain. The somata ranged from 5 to 15 μm in diameter. The RhG had a variety of regions including distinctive clusters of somata, neuropil, and axon tracts. The axon tracts were separated by glial cells, which were often associated with exosomes. Some axons traversed the ganglion without synapsing. Neurons had unique ultrastructural features including large membranous particles, di#erent staining densities, vesicles of varying sizes, and vesicle-free neurites. We found some neuronal somata that projected an axon into the nerve connective to the cerebral ganglion. This connective contained about 30,000 axons, some as small as 90 nm in diameter. We are applying machine learning algorithms to automatically segment all the cells and neuronal processes intrinsic to and coursing through the RhG to provide a first draft of the connectome. A complete connectome of this ganglion will provide insights into the structural organization of this enigmatic ganglion, which is likely to be involved in higher order olfactory processing in this mollusc.

35: Sele, Nisan

Amherst College Biology & Neuroscience Program

Zyxin: a novel regulator of actin dynamics in dendritic spines

Sele N., Schuldt B.R., Varona Ortiz A.B., Kim S.A.

Morphological changes at synapses during development refine neuronal circuitry and are thought to be the substrate for long-term information storage in the nervous system. The cytoskeleton regulates postsynaptic structure and function, yet the requisite players remain not well understood. Zyxin is a focal adhesion protein that promotes cytoskeletal reorganization and has been characterized in fibroblasts. Here, we establish zyxin as a novel postsynaptic protein and describe its recruitment to dendritic spines in response to neuronal activity. Concentrated in the soma and dendrite, zyxin was also found in dendritic protrusions throughout neurodevelopment (DIV 6-21) with distinct colocalization with actin at the tips of filaments, the sites of polymerization. In addition, zyxin in dendritic spines was dynamic with increases following depolarization and mechanical stimulation. Zyxin mobilization was impaired in the presence of myosin II inhibitor blebbistatin, which demonstrates myosin II plays a role in the transport of zyxin to dendritic spines. However, the translocation of zyxin is not dependent on myosin II: when we inhibited myosin II and applied high potassium stimulation, we observed changes in zyxin localization. These findings suggest that zyxin acts as a modulator of F-actin in the postsynaptic compartment and responds to environmental signals, contributing to synapse maturation.

36: Spool, Jeremy

Psychological & Brain Sciences

Descending Auditory Control of a Hypothalamic Nucleus Involved in Social Behavior and Feeding

Spool J; Lally A; Chen P; Remage-Healey L

To engage in healthy social interactions, the brain must coordinate processing of social sensory cues (i.e., visual, auditory) with appropriate social responses. While complex features of social signals are processed in the telencephalic pallium, nuclei controlling social behaviors, called the social behavior network (SBN; conserved across vertebrates), reside mainly in the diencephalon. In songbirds, for example, the ability to learn dozens of individuals by their vocalizations depends on auditory pallium, while the SBN are necessary for appropriate social responses to songs and calls. Tremendous progress has been made in studying pallial sensory circuits and the SBN largely in parallel, but apart from mammalian olfactory systems we have little knowledge about their intersection. We asked whether auditory pallial circuits contribute to the SBN responses to social sensory cues. We transiently inactivated auditory pallium of female Zebra finches with inhibitory neurotransmitter receptor agonists during song playback, and examined song-induced immediate early gene (egr-1) activation in SBN nuclei. Auditory pallial inactivation specifically impaired egr-1 responses to song in the lateral ventromedial nucleus of the hypothalamus (VMHl), providing the first evidence in vertebrates of a connection between auditory pallium and the SBN. An ANCOVA additionally revealed a relationship between egr-1 expression in VMHl and feeding behavior. Feeding behavior correlated with VMHl egr-1 in 3 out of 4 experimental treatments: control birds exposed to silence, and birds with inactivated auditory pallium exposed to either song or silence; this is consistent with the dual roles of VMH in homeostatic regulation and social behavior. However, this correlation specifically did not include control animals exposed to auditory playback, indicating that auditory input from pallium to VMHl may mediate a trade-off between social attention and feeding. Electrophysiological recordings from VMHl in both female and male Zebra finches reveal a large proportion of single units that are highly responsive to ecologically-relevant bird songs and calls. Female single units had stronger responses to auditory stimuli compared to males, and male single units were selective for contact calls over playback of male songs. These data highlight a role for an auditory pallium to VMHl circuit in the integration of social auditory stimuli with internal state to influence social decision-making.

37: Tait, Cheyenne

Biology

The olfactory system in the mollusc Berghia stephanieae

Tait C. C.; Ramirez M. D.; Katz P. S.

Olfactory systems in arthropods and vertebrates show remarkable neuroanatomical similarities, with primary sensory neurons projecting to specialized regions in the brain. It is not known if this similarity extends to molluscs. We used neurobiotin tracing, immunohistochemistry, and in situ hybridization chain reaction to determine the neuroanatomical organization of the olfactory system in the nudibranch mollusc, Berghia stephanieae. Like most gastropod molluscs, Berghia has posterior tentacles (termed rhinophores in nudibranchs) that are specialized for distance chemoreception. Several populations of primary sensory neurons line the epithelium of the rhinophore, including histaminergic and peptidergic neurons. Some histaminergic primary sensory neurons in the rhinophore project centrally through two rhinophore nerves and terminate in the rhinophore ganglion (RhG), which sits at the base of the rhinophore. A population of primary sensory axons bypass the RhG and project through the rhinophore connective directly into the central ring ganglia (CRG), with many continuing through the commissure to the contralateral brain hemisphere and RhG. Other axons from the rhinophore nerves terminate in many neuropil regions throughout the CRG. In addition to sensory neurons, there are morphologically distinct peptidergic neurons found deeper within the rhinophore tissue, which may be interneurons. This suggests key roles for neuropeptides in gastropod olfaction. Finally, we found extensive efferent innervation of the rhinophores including the axons of identified peptidergic and serotonergic neurons in each ganglion of the CRG. Neurobiotin tracing also filled a photoreceptor in each eye. Thus, there is neurochemical complexity within the rhinophore and widespread multimodal connectivity between the rhinophore and the rest of the brain. The results from this project suggest that the organization of this molluscan olfactory system is substantially different from that seen in arthropods and vertebrates.

38: Teves, Catarina

Psychological and Brain Sciences

Investigating the changes in myelin dynamics in the mPFC following binge drinking in adolescent mice

Akli S, Senthilkumar R, Nouduri S, Teves C, Amirault J, Richardson HN

Studies in humans and rodents have shown that binge drinking can lead to cognitive impairments as well as loss of white matter, which contains densely packed myelinated axons. Myelin is formed by oligodendrocytes, which differentiate from oligodendrocyte precursor cells (OPCs). Myelin sheaths insulate axons and allow for faster and energy-efficient propagation of electrical impulses. In studies using rodent models, adolescent binge drinking significantly decreased prefrontal white matter and decreased expression of myelin oligodendrocyte glycoprotein (MOG), a protein that resides in the outer membrane of myelin sheaths. The mechanisms by which myelin is lost following adolescent alcohol drinking are not well understood. A recent study found that alcohol exposure in adult mice decreased newly generated myelin and mature oligodendrocytes but did not cause a reduction in OPC cell density. This suggests the effects of alcohol occur later in myelin development and possibly interrupt oligodendrocyte differentiation, maturation, or active myelination of axons. We hypothesize that alcohol exposure in adolescence affects myelin through a similar mechanism. To study this, we used a Cre-lox transgenic mouse model (NG2-CreER:Tau-mGFP) that allows for conditional expression of mGFP in the membranes of myelinating oligodendrocytes and allows us to track the maturation of oligodendroglial lineage cells and the formation of myelin. After inducing recombination on postnatal day 21, male and female mice were exposed to alcohol for four weeks during adolescence using the drinking in the dark paradigm. Brain tissue was processed coronally sectioned for immunohistochemical studies. Following immunolabeling of MOG and mGFP in prefrontal cortex sections, we will use confocal imaging to visualize and quantify newly developing myelin and preexisting myelin in the prefrontal cortex. Immunolabeling for MOG and mGFP will allow us to visualize pre-existing myelin sheaths (mGFP-/MOG+) and late-development myelin sheaths (GFP+/MOG+). This will help us understand how alcohol consumption interrupts the developmental process of myelin generation in adolescence.

39: Wang, Yuqi

Neuroscience department, Smith College

Gpr37a Regulates Retinal Stratification and Müller Glial Maturation in Zebrafish

Wang Y; Liao Z; Pathak N; Owino S

40: Weinberg, Max

NSB

The Effect of Habituation on Neural Response in the Accessory Olfactory Bulb in Laboratory Mice

Weinberg M; Dwyer J; Dickinson S; Bergan J;

The vomeronasal system(VNS) in most vertebrates is responsible for the detection of pheremonal signals and is necessary for adaptive social behavior. The accessory olfactory bulb is the second node in this pathway, receiving inputs from the vomeronasal organ(VNO) and outputting primarily to the medial amygdala. Previous research has shown that knocking out the VNO in mice leads to robust sex-specific changes in behavior and that the AOB displays stereotyped responsiveness to conspecifics. However, the research has not characterized fully how in real time the AOB responds to conspecific and non-conspecific stimuli, particularly at the population level. Therefore, we investigated the AOB’s response to these stimuli at the population level in real time. Because animals need to adapt their behavior in real time, we hypothesized that we would see decreased response with each presentation. Our approach involved using a combination of calcium sensors of neural activity and fiber-photometry. We also designed a behavior box to present stimuli for discrete and controllable periods of time which allowed us to examine the effects of habituation on the AOB’s response. We see evidence of differential response depending on the sex of the stimulus animal, and a change in response over repeated presentations of the same animal. Intriguingly, we have also found evidence of a robust trough prior to spike in response to conspecifics and consistent oscillations in the AOB’s population code.

41: Winsor, Alex

Biology

Cross-modal cues increase retinal activity in a jumping spider

Winsor AM, Jakob EM

Most visually guided animals shift their gaze to selectively attend to specific features of their environment. In previous work using a custom-built eyetracker, we showed that jumping spiders (Phidippus audax) preferentially direct the gaze of their movable high-acuity principal eyes to objects with particular features. Here, we tested whether gaze direction is also influenced by the presence of conspecific pheromones. Our results show that when exposed to pheromones of the opposite sex, males, but not females, were more likely to divert their attention away from an initial stimulus to a distractor that suddenly appeared. We also tested whether spiders exposed to pheromones were more likely to look at images of conspecifics. While male spiders exposed to pheromones significantly increased retinal scanning when viewing an image series of neutral shapes, prey, or conspecifics, this increase was independent of stimulus type. Similarly, spiders did not appear to discriminate between ethologically relevant objects presented simultaneously in an array. Thus, while pheromone exposure led to increased eye movements, we found no evidence for higher-order strategies such as search image formation or guided visual search. These results align with other experiments investigating the influence of sound on gaze direction. Shifts in visual attention are thus likely to be a product of general increases in arousal, possibly mediated by simpler mechanisms such as neuromodulation.

42: Wong, Tiffany

Biochemistry and Molecular Biology

Tau Uptake in the Abundance of Clusterin

Tiffany Wong, Andrew Schultz, Jennifer Rauch

Tau is an intrinsically disordered protein that is prone to aggregation during many different tauopathies, namely Alzheimer's Disease. Aggregated tau is able to spread from cell to cell in the brain which causes progressive cell death and thus a decline in cognitive function. The manners in which tau is able to spread is a growing field of interest as more is understood about the brain as a whole. Currently, it is theorized that extracellular chaperone protein, clusterin, is able to facilitate tau seeding and spread by stabilization. Previous research in our lab illustrates relevant protocols and subsequent results of tau uptake into mouse neuroglioma (H4) cells under typical conditions. It is with this preliminary understanding of typical tau uptake under normal conditions that we may assess how the presence of sClusterin is able to affect this tau uptake assay.

43: Yusuf, Issa

Biochemistry and Molecular Biotechnology

Protein citrullination marks myelin protein aggregation and disease progression in ALS

Yusuf IO; Qiao T; Parsi S; Tilvawala R; Thompson PR; Xu Z.

Protein citrullination is a posttranslational modification that involves the irreversible conversion of protein-arginine to protein-citrulline and is catalyzed by a family of enzymes known as protein arginine deiminases (PADs). Mammals encode five PADs, and PAD2 is the most dominant and ubiquitous isoform in the central nervous system (CNS). Aberrant protein citrullination and PAD2 dysregulation have been demonstrated in several neurodegenerative diseases. To determine whether this is the case for amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease characterized by motor neurons loss, paralysis, and subsequent death, we investigate protein citrullination and PAD2 in two different transgenic mouse models of ALS expressing human mutant SOD1G93A and PFN1C71G. We report that protein citrullination and PAD2 expression are dynamically altered in the spinal cord during the progression of disease, increasing progressively in astrocytes with reactive astrogliosis, while decreasing in neurons and their axons. Furthermore, in the spinal cord white matter, citrullinated proteins accumulate as protein aggregates containing myelin proteins PLP and MBP. Likewise, citrullinated proteins progressively accumulate in insoluble protein fractions during the disease progression. Interestingly, the increases in PAD2 expression and protein citrullination spatially correlates with CNS areas with the most severe motor neuron degeneration. We also validated our findings in sporadic ALS patient’s spinal cord and motor cortex and found protein citrullination increased, correlate with reactive astrogliosis, and forms aggregates that contain PLP and MBP in patients compared to non-neurological controls. These results suggest that increased protein citrullination and PAD2 dysregulation are critical characteristics of reactive astrogliosis, motor neuron degeneration, and myelin protein aggregation in the pathogenesis of ALS, and may serve as another pathological marker of the ALS disease progression.

44. Zhang, Sidong

College of Information and Computer Sciences

Increasing Trust in Alzheimer's Disease Forecasting

Sidong Zhang, Evan Fellman, Genglin Liu, James Ko, Madalina Fiterau

Alzheimer’s disease (AD) is the most common form of dementia, causing progressive cognitive impairment, disorientation, and memory loss. Despite years of clinical trials, there is currently no cure for AD and, by the time of diagnosis, as much as 60% of brain matter is already lost. Thus, forecasting Alzheimer's disease years ahead of onset is critical for attempts at early treatment, the selection of subjects for clinical trials, and to facilitate neurologists’ study of the disease.

Past research on machine learning for Alzheimer’s disease prediction was limited to using cognitive test scores and highly engineered volumetric features, while failing to leverage the potential information found in brain MRIs. Attempts to train 3D and 2D CNNs on the MRIs have been unsuccessful thus far, due to the insufficient amount of data samples available for the massive amount of parameters that need to be learned. Moreover, forecasting AD using standard statistical models, simple MLPs and sequential models is typically limited to 6-12 months windows, model stability and performance dropping significantly for longer time windows.

To introduce more complex longitudinal data and detect future disease stages, we propose a sequential deep learning approach that is expressive enough to handle multimodal longitudinal data, with an added unsupervised mutual information CNN encoder to process the 3D MRI scans, while still maintaining stable forecasting performance over forecasting windows of two years or more. We integrate certain domain knowledge via selective features of the disease-relative areas’ volumetric data, cognitive test scores and demographic information. The model is designed to get latent features from the multimodal data during the training process that are informative to the forecasting task. To achieve this, we propose a hybrid model of RNN and CNN. On the RNN side, we study a RNN-like structure introducing latent anticipated features to enhance the forecasting performance. On the CNN side, we train a mutual information based unsupervised encoder and extract latent features from the 3D MRIs as supportive side information. The model we are developing will be capable of performing forecasting tasks 2-year ahead of time, while the instability issue brought by long-term forecasting is addressed by our new mechanism of training different parts of the model separately in different stages. The future goal of the project lies in forecasting the disease on a longer time gap without loss of accuracy and robustness.

UMass Neurosciences Fall 2022 Poster Conference

1: Anderson, Lucy

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2: Balaji, Vibha

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3: Barnes, Morgan

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4: Belculfine, Samantha

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5: Berlin, Annika

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6: Camille, Webb

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7: Christensen, Jennifer

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8: Correll, Erika

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9: De Anda Gamboa, Cassidy

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10: Deater-Deckard, Kirby

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11: Delvey, Cassandra

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12: Falcy, Brennan

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13: Flores Bonilla, Annabelle

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15: Fox, Quinn

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16: Fu, Chen

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17: Guzmán Clavel, Luis

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18: Hoff, Chloe

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19: Huang, Wanyun

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20: Isaacs, Emily

Transgenic tagging and tracking of oligodendroglia for spatial and temporal mapping de novo myelination patterns in the mouse brain.

21: Karuvally, Arjun

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23: Liao, Zhixin

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24: Lin, Hongtong

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25: Malekzadeh, Masoud

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26: Nie, Zhen

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28: Niroula, Pratima

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29: Nulman, Jonathan

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30: Pearson, Gregory

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31: Perk, Chris

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32: Ramirez, Desmond

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33: Rodberg, Ellen

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34: Sant, Harshada

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35: Sele, Nisan

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36: Spool, Jeremy

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37: Tait, Cheyenne

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38: Teves, Catarina

Investigating the changes in myelin dynamics in the mPFC following binge drinking in adolescent mice

39: Wang, Yuqi

Gpr37a Regulates Retinal Stratification and Müller Glial Maturation in Zebrafish

40: Weinberg, Max

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41: Winsor, Alex

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42: Wong, Tiffany

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43: Yusuf, Issa

UMass Neurosciences
Fall 2022 Poster Conference