Cortical cells, circuits, and signals - and their roles in motor behavior and disease


An essential aspect of human behavior is the ability to perform skilled and purposive movements, particularly with our hands. This ability relies on the cerebral cortex, and in particular on the input-output operations performed by its neurons, which are embedded in complex networks of synaptic circuits. Our lab aims to understand the cellular connectivity and dynamic signaling in these circuits. We focus on mouse motor cortex and its connections with upstream and downstream partners throughout the brain and spinal cord via different types of projection neurons. Further goals are to understand cellular mechanisms for motor control in behaving animals, and how cortical cells, circuits, and signals are affected in neurological diseases such as paralysis, neurodevelopmental disorders, and more.

Optogenetic-electrophysiological dissection of the synaptic connections that layer 6 corticothalamic (CT) neurons in motor cortex do - or don't - form with other types of cortical projection neurons (IT and PT) and with thalamocortical (TC) neurons (Yamawaki & Shepherd, 2015)

High-frequency, optogenetic, laser-scanning photostimulation of excitatory synaptic input to a corticospinal neuron to test the role of HCN channels and dendritic integration in translating excitatory postsynaptic potentials (EPSPs) into action potentials (APs) (Sheets et al., 2011).

Layer 4 pyramidal neuron in motor cortex; from Yamawaki et al. (2014)

Laminar connectivity matrix analysis of local excitatory connections among pyramidal neurons across layers in mouse motor cortex (Weiler et al., 2008)

Shepherd Lab

Department of Physiology & NUIN

Feinberg School of Medicine

Northwestern University

303 East Chicago Avenue

Chicago, IL 60611

Mouse corticospinal motor cortex

© 2015 Gordon Shepherd Lab. All rights reserved.

Corticospinal neurons (Suter & Shepherd 2015)