NEE Seminar Series

2025-11-15      김민환 교수님 (대구경북과학기술원(DGIST) 뇌과학과)

시간: 2025년 11월 15일(목) 13:00 장소: 이화여대 아산공학관 521호

제목: Target cell-specific synaptic dynamics of excitatory to inhibitory neuron connections in supragranular layers of human neocortex

초록:    Rodent studies have demonstrated that synaptic dynamics from excitatory to inhibitory neuron types are often dependent on the target cell type. However, these target cell-specific properties have not been well investigated in human cortex, where there are major technical challenges in reliably obtaining healthy tissue, conducting multiple patch-clamp recordings on inhibitory cell types, and identifying those cell types. Here, we take advantage of newly developed methods for human neurosurgical tissue analysis with multiple patch-clamp recordings, post-hoc fluorescent in situ hybridization (FISH), machine learning-based cell type classification and prospective GABAergic AAV-based labeling to investigate synaptic properties between pyramidal neurons and PVALB- vs. SST-positive interneurons. We find that there are robust molecular differences in synapse-associated genes between these neuron types, and that individual presynaptic pyramidal neurons evoke postsynaptic responses with heterogeneous synaptic dynamics in different postsynaptic cell types. Using molecular identification with FISH and classifiers based on transcriptomically identified PVALB neurons analyzed by Patch-seq, we find that PVALB neurons typically show depressing synaptic characteristics, whereas other interneuron types including SST-positive neurons show facilitating characteristics. Together, these data support the existence of target cell-specific synaptic properties in human cortex that are similar to rodent, thereby indicating evolutionary conservation of local circuit connectivity motifs from excitatory to inhibitory neurons and their synaptic dynamics.

2025-05-29      강미선 박사님 (한국뇌연구원(KBRI) 정서인지질환 연구그룹)

시간: 2025년 5월 29일(목) 14:00 장소: 이화여대 아산공학관 521호

제목: Role of phospholipase Cη1 in lateral habenula astrocytes in depressive-like behavior in mice

초록: Phospholipase C (PLC) enzymes are key regulators of intracellular calcium signaling and have been implicated in various psychiatric disorders, including depression, epilepsy, and schizophrenia. While several PLC subtypes have been extensively studied, the physiological role of the recently identified PLCη family remains unclear. Here, we identify prominent expression of PLCη1 in astrocytes of the lateral habenula (LHb), a brain region critically involved in mood regulation. To investigate its function, we generated astrocyte-specific PLCη1 conditional knockout (cKO) mice (Plch1f/f;Aldh1l1-CreERT2). In these cKO mice, LHb astrocytes exhibited reduced morphological complexity. These astrocytic alterations were accompanied by increased synaptic efficacy and elevated firing rates of LHb neurons, as well as impaired extra-synaptic long-term depression (LTD). Additionally, tonic AMPA and NMDA receptor-mediated currents and extracellular glutamate levels were significantly reduced. Remarkably, chemogenetic activation of LHb astrocytes rescued the diminished tonic AMPAR/NMDAR currents in cKO mice. Behaviorally, LHb-targeted deletion of PLCη1 using AAV-GFAP-Cre induced depressive-like behaviors, which were reversed by astrocyte-specific chemogenetic activation. Finally, exposure to restraint stress led to a downregulation of Plch1 mRNA in the LHb.Together, these findings uncover a critical role for astrocytic PLCη1 in maintaining LHb circuit function and emotional behavior, suggesting that PLCη1 is a promising target for therapeutic intervention in depression and related neuropsychiatric disorders.

2025-01-21      최영빈 교수님 (서울대학교 의과대학 의공학교실)

시간: 2025년 1월 21일(화) 10:30 장소: 이화여대 아산공학관 521호

제목: Batteryless, Implantable Devices Enabled with On-demand Drug Delivery

초록: Self-injectable therapy has several advantages in the treatment of chronic diseases. However, frequent injections with needles impair patient compliance and medication adherence. To resolve this, many implantable systems have been actively sought to permit on-demand drug delivery without invasive multiple skin punctures. However, they often require electrical power supplies (e.g., batteries) and thus, they are large and heavy for implantation. Therefore, in this talk, we introduce our implantable devices enabled with patient-driven, on-demand drug release without electric power sources. We design the pumps to be actuated by an externally applied magnetic field, which can release an accurate amount of drug only when a magnetic field is applied outside the body. The other type of an implantable device is embedded with multiple drug reservoirs that are capped with a stimulus-responsive membrane (SRM), which can be ruptured by noninvasive near-infrared (NIR) irradiation from the outside skin, hence opening a single selected reservoir to release the drug. For the last, we develop a device capable of on-demand administration of self-injection drugs via noninvasive manual button clicks on the outer skin. The implantable devices herein exhibit the pharmacokinetic and pharmacodynamic profiles, similar to those in animals treated with conventional subcutaneous drug injections. Therefore, we conclude that the systems proposed in this work are promising for noninvasive, on-demand drug administrations.

2025-01-16     노경철 교수님 (아주대학교 의과대학 의학과)

시간: 2025년 1월 16일(목) 13:00 장소: 이화여대 아산공학관 521호

제목: Astrocytes at Play: Shaping Dominance and Winning Memories

초록: Winning can make you more likely to succeed in future competitions, thanks to something called the “winner effect”. This boost in confidence and dominance comes from memories of past victories. But how does the brain create and store these winning memories, and how do they shape social status? In this seminar, I will discuss a recent research highlighting the role of certain brain cells, called astrocytes, in the prefrontal cortex – a part of the brain important for decision-making and social behavior. By recording astrocyte activity during social competition, we found that these astrocytes are activated after a win, helping the brain lock in memories of success. This activation depends on a signal from another brain area called the ventral tegmental area, which sends a dopamine to reinforce the memory. Interestingly, enhancing astrocyte activity strengthened winning memories, while suppressing it made those memories weaker. These findings reveal how the brain’s chemistry supports the “winner effect” and helps establish social hierarchies.