Samuel M. Schacher, PhD
Professor of Neuroscience (in Psychiatry)
Neural circuits controlling behavior have three fundamental properties: Individual components of the circuit form connections with specific partners with appropriate synaptic baselines that can have the capacity to be modified for long durations by activity-dependent mechanisms.
My lab is interested in understanding the cellular and molecular mechanisms that regulate these properties of a behaviorally relevant neural circuit – the sensori-motor synapse – in the marine mollusk Aplysia. Sensory neurons form synapses with specific motor neurons that mature and maintain a synaptic baseline that can be modified in a bidirectional manner for short and long durations by activity known to produce long-lasting bidirectional changes in behavior. We have found that interactions of cell adhesion molecules, activation of sequential cascades of specific signaling pathways involving the timely secretion of neurotrophin-like peptides with autocrine and paracrine actions contribute to these various phases of synapse development and maturation and long-term plasticity associated with behavioral adaptations. We wish to understand how the timely activations of these pathways produce specific regulation of gene transcription/activation, local and cell-wide protein translation, and the network of interacting processes that balance the strength of synapses in a mature neural circuit.