（１）In our laboratory, we are interested in understanding how dendrites contribute to various computations performed by cortical neurons. We and other labs, have shown that nonlinear dendritic properties can contribute to place field formation, visual and somatosensory receptive fields. We aimed to investigate how these nonlinear dendritic properties contribute in computations performed in the motor cortex. I will describe the integrated behavioral and imaging platform we built to investigate the motor cortex in mice. We use a dexterity task, calcium imaging, optogenetic perturbations, and behavioral manipulations.
 

（２）Parkinson's Disease (PD) is a common neurodegenerative disease, which markedly disrupts motor performance. The basal ganglia (BG), the main brain system affected by PD, exerts their physiological effects mostly by modulating neocortical activity via the cortico-BG-cortical loop. The primary motor cortex M1, integrate data from multiple brain regions, including the BG, to generate motor output commands to the brain stem and spinal cord. Thus, although PD primarily targets the basal ganglia, the motor consequences BG disruption leading to motor disability is expected to be mediated by impairment of the M1 network dynamics.
We  in control and 6-hydroxydopamine (6OHDA) induced Parkinsonian mice. Our findings showed that experimental PD dramatically disrupted motor performance. Concomitantly, activation intensity of individual layer-5 PT neurons was markedly attenuated, and activation network dynamics of both layer-5 PT neurons and layer 2-3 pyramidal neurons was disrupted after induction PD. Optogenetic activation of M1 partially improved motor performance of PD mice. General linear model (GLM) analysis revealed reduced encoding of discrete motor parameters of layer-5 PT neurons in Parkinsonian mice. Finally, PD disrupted the stability of the layer-5 PT neuronal network with respect to both recruitment order dynamics of neurons and encoding of individual motor parameters of the task. These findings shed new light on the mechanisms underlying motor disabilities in PD, and identifies novel potential therapeutic targets for PD patients.