RESEARCH

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Neuromodulatory circuits regulating goal-directed spatial learning

Place cells and the synaptic plasticity that builds them are shaped by the brain's neuromodulator state as an animal learns what matters to learn specific environment or contexts. Neuromodulators signal salience, novelty, and reward, and in doing so determine when the hippocampus is permitted to learn and which neurons are recruited into a spatial map. Understanding this gating is essential to explaining why some experiences become memories and others do not. In the lab, we focus on norepinephrine and locus coeruleus input to the hippocampus during goal-oriented navigation, using a custom in-house linear track combined with miniscope calcium imaging, fiber photometry of genetically encoded sensors, and optogenetic manipulation to link neuromodulator dynamics to place-cell formation.

Metabolic signalling in behaviourally relevant plasticity

Synaptic plasticity is among the most energetically demanding processes a neuron undertakes, and it is executed locally, at individual spines and branches. This makes metabolic state a plausible but largely unexamined constraint on where and when plasticity can occur. We study ER–mitochondria interactions and AMPK signaling as control points linking local energy supply to synapse specific plasticity. A central effort in this research arm is the development of FRET-based biosensors that can report real time organelle interaction and metabolic signaling in living neurons during behaviorally relevant plasticity. These sensor imaging will be combined with whole cell patch clamp electrophysiology to link biochemical computation to functional changes at the synapse.

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Molecular mechanisms of synapse specificity during BTSP

Behavioral timescale synaptic plasticity potentiates synapses that were active seconds before a dendritic plateau, far outside the window of classical Hebbian rules. How specificity is preserved across such a long eligibility trace is one of the central unresolved questions in the field. We dissect the molecular signaling that confers this precision, focusing on mGluR and BDNF–TrkB pathways. Whole-cell electrophysiology and two-photon imaging of FRET sensors let us follow these cascades at identified spines during BTSP induction, while computational modeling tests whether the measured dynamics are sufficient to account for its spatial and temporal precision.

Sex differences underlying spatial navigation and BTSP

Sex differences in spatial learning are well documented at the behavioral level, yet the synaptic and molecular mechanisms that produce them remain largely unexplored, in part because plasticity has historically been characterized in males alone. Gonadal hormones act rapidly on hippocampal synapses, making them strong candidates for shaping how spatial maps are built. We examine how estradiol modulates BTSP and hippocampal representations of space, using our linear-track platform together with whole-cell patch-clamp electrophysiology to characterize plasticity across the estrous cycle and under defined hormonal conditions.