Event Detail (Archived)
Firing Rate Homeostasis in Neocortical Networks
- Friday Lecture Series
Gina G. Turrigiano, Ph.D., Joseph Levitan Professor of Vision Science, department of biology, Brandeis University
Neocortical networks must generate and maintain stable activity patterns despite perturbations induced by learning and experience- dependent plasticity, and this stability must be maintained across distinct behavioral states with very different sensory drive and modulatory tone. There is abundant theoretical and experimental evidence that network stability is achieved through homeostatic plasticity mechanisms that adjust synaptic and neuronal properties to stabilize some measure of average activity, and this process has been extensively studied in primary visual cortex (V1), where chronic visual deprivation induces an initial drop in activity and ensemble average firing rates (FRs), but over time activity is restored to baseline despite continued deprivation. Dr. Turrigaino will discuss recent work from the lab in which they follow bidirectional FR homeostasis in individual V1 neurons in freely behaving animals, as they cycle between natural periods of sleep and wake. They find that - when FRs are perturbed by visual deprivation or eye re-opening - over time they return precisely to a cell-autonomous set-point. Intriguingly, this firing rate homeostasis is gated by sleep/wake states in a manner that depends on the direction of homeostatic regulation: upward firing rate homeostasis occurs selectively during periods of active wake, while downward firing rate homeostasis occurs selectively during periods of sleep. These data indicate that neocortical plasticity is regulated in a complex manner by vigilance state and raise the possibility that temporal segregation of distinct plasticity mechanisms is important for proper circuit refinement.
Dr. Turrigiano received her bachelor’s degree in biology from Reed College in 1984 and her doctorate in neuroscience from University of California, San Diego in 1990. She then trained as a postdoc with Eve Marder at Brandeis University before joining the faculty in 1994. Her scientific interests include understanding how experience rewires cortical microcircuitry, and the stabilization of network function by homeostatic plasticity mechanisms. She has received many awards for her research, including a MacArthur Foundation fellowship, McKnight Foundation Technological Innovation and Brain Disorders awards, a National Institutes of Health Director’s Pioneer Award, the Nakasone Award, Javitz Neuroscience Investigator and MERIT awards, and was recently elected to the American Academy of Arts and Sciences and the National Academy of Sciences.
- Open to
- Priya Rajasethupathy
- Refreshments, 3:15 p.m. - 3:45 p.m., Abby Lounge
- Justin Sloboda
- (212) 327-7785