Neurons in local neuronal circuits are interconnected via synaptic connections that can experience dramatic changes in strength during ongoing neuronal activity. How synapses are regulated on a time scale of tens of milliseconds to tens of seconds is not well understood. Our laboratory uses a combination of electrophysiology, imaging, and optogenetics to explore the dynamic properties of distinct types of synapses in the thalamocortical system of rodents. We are particularly interested in the mechanisms underlying short-term synaptic plasticity and their importance for proper functioning of local neuronal circuits. Ultimately this knowledge will aid in understanding the computations performed in neuronal networks that mediate perception, memory formation and higher cognitive functions.
Optical stimulation of cholinergic afferents in the thalamic reticular nucleus generates thalamic network activity. Left: Channelrhodopsin-expressing cholinergic axons from the basal forebrain labeled by GFP target the thalamic reticular nucleus (TRN) but not the ventral posteromedial nucleus of the thalamus (VPM). Right: Schematic of cholinergic synaptic signaling in the TRN, mediated by both nicotinic and muscarinic receptors (top). TRN postsynaptic responses, evoked by optical stimulation of cholinergic axons (bottom).
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|Synchronous activity in inhibitory neocortical neurons interconnected by electrical synapses.|