Projects

 

Synaptic circuit organization of motor cortex: Synaptic circuits in motor and related areas of cortex engage in neural operations underlying diverse aspects of cognition and behavior – motor control, executive functions, working memory, sensorimotor integration, and more. A major interest of our lab is to understand the circuit organization across multiple levels, from ion channels to local circuits to large-scale networks and behavior. We use multiple circuit-analysis techniques, including in vivo stereotaxic delivery of viruses and tracers to label projection neurons, and circuit mapping based on in vitro optogenetic and glutamate-uncaging laser-scanning photostimulation (LSPS) combined with whole-cell electrophysiology to sample postsynaptic responses. Current projects include studies of corticothalamic, thalamocortical, and corticocortical connections in the extended network for sensorimotor integration.

"Two thumbs up" - how mice use their hands and digits for manual dexterity: High-speed close-up video reveals a set of kinematic building-blocks and an outsized role for the thumbs as mice handle food (Barrett et al., 2020). Current work aims to characterize these "motor primitives" in greater detail, and identify the sensorimotor circuits that mediate this ethologically important aspect of forelimb-dependent behavior.

 

In vivo analysis of cortical projection neurons: An ongoing effort is to build on knowledge gained from slice-based studies of cortical circuits to understand how these cells and circuits are involved in generating motor behavior. We use multiple methods to monitor (GCaMP imaging, linear array ephys) and manipulate (optogenetic activation and silencing) the activities of corticospinal and other motor cortex projection neurons.

Funding

 

Current: NIH; National Institute of Neurological Disorders and Stroke (NINDS)

Past: Whitehall, Simons, BRF, & Rett Syndrome Research Foundations; NIH (NIDCD, NIBIB)

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Shepherd Lab

Department of Physiology & NUIN

Feinberg School of Medicine

Northwestern University

303 East Chicago Avenue

Chicago, IL 60611

Mouse corticospinal motor cortex

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