Dwight Bergles, Ph.D. - The Soloman H. Snyder Department of Neuroscience
Johns Hopkins University School of Medicine
Kavli Neuroscience Discovery Institute
Neural pathways that process sensory information rely on both genetically preprogrammed events and active refinement to establish proper connectivity. Remarkably, active processes begin prior to the onset of sensory experience, when neurons fire spontaneous periodic bursts of action potentials. This highly stereotyped, intrinsically generated activity promotes neuronal survival, maturation and initial refinement of their connections. In the auditory system, spontaneous activity arises within the cochlea prior to hearing onset. During this critical developmental stage, glia-like supporting cells that surround inner hair cells spontaneously release ATP, triggering a cascade of events that ultimately results in hair cell depolarization, glutamate release and bursts of activity in groups of auditory neurons that will ultimately process similar frequencies of sound. We used electrophysiological recordings in isolated cochleae and in vivo imaging of auditory neuron activity from pre-hearing mice to uncover the complex molecular steps used to activate hair cells before hearing onset and the macroscopic patterns of activity exhibited by auditory neurons before hearing begins. I will discuss how glial cells control hair cell activity to promote correlated activity of neurons and astrocytes in this developing sensory system.
Jan 25, 2021 @ 4:00 p.m.
Host: Neuroscience Graduate Program