Time: 14:00-15:30 on Mon.,Aug.14, 2023

Venue：E203, Biomedicine Hall

Speaker: Dr.Mac Hooks

Host: Dr.Zengcai Guo

Title: Steps towards tracking motor circuit changes during skill learning

Abstract：

Primary motor cortex is required for the learning and control of skilled movements. Despite detailed work on plasticity in sensory cortical areas, the circuit mechanisms, including synaptic changes, that occur during learning are poorly understood. Here we develop a motor skill task, accelerating rotarod, which can be learned by mice across ages and monitored with high speed videography. First we characterize how skill acquisition varies with age and how the motor performance changes during learning. Because inhibitory circuitry is implicated in cortical plasticity, we next characterize inhibitory circuit changes following training, finding rapid changes in fast spiking connections to task-active (but not task-inactive) pyramidal neurons. These methods are limited, however, because tracking synaptic changes over time in the same mouse is challenging.  We lastly begin to develop a method for quantifying  excitatory synaptic connection strength in vivo with the aim of tracking changes in input to the same neurons in motor cortex at a range of periods following motor skill training. Our goal is to identify specific circuit changes associated with learning and the times following training at which they occur. This will offer insight into the circuit mechanisms of cortical plasticity in motor areas, which remain relevant for new skill acquisition throughout adulthood.

Biography：

Bryan Hooks is a native of Montgomery Village, Maryland. He graduated from Harvard University in 1996 with AB (summa cum laude) and AM degrees in Biology.  He completed his PhD in Neuroscience at Harvard Medical School and Children’s Hospital Boston. His research focuses on activity dependent modification of retiogeneiculate synapses, under supervision of Chinfei Chen. Then he completed his postdoc training under supervision of Karel Svoboda and Gordon Shepherd at Janelia Research Campus from 20007-2015, before moving to University of Pittsburg School of Medicine as an assistant professor in the department of neurobiology. He published multiple papers in Neuron, Nature Communications, and J of Neuroscience. His research focuses on the micro-circuitry of the sensori-motor cortex that is underlying sensorimotor integration and motor learning. Specifically, he combines optogenetic stimulation and patchclamp recording, a method called CRACM developed in the Svoboda lab to study local and long-range circuits to pyramidal and interneurons. He further extended the technique to manipulate two independent pathways by using dualchannel photostimulation.