Control of Neural Synchrony

Date(s) - 11/22/2010
5:00 pm - 6:00 pm

Dr. Sachin S. Talathi, Dept of Pediatric Neurology, University of Florida

Neural synchrony generally refers to the pattern of precisely coordinated dynamics of large numbers of heterogeneously connected networks of neurons, within a given region of the brain or between multiple brain regions, leading to the generation of macroscopically observable brain rhythms. Neural synchrony mediated by network of interneurons, in particular, play an important role in the generation of gamma rhythms (20-80 Hz) in the brain. These rhythms contribute to cognitive functions such as memory formation and sensory processing and are disturbed in certain psychiatric disorders such as autism and schizhophrenia. A possible modality of therapy for these illnesses is through novel brain stimulation techniques that attempt to selectively induce inhibitory neuronal synchrony and thereby restore gamma rhythms in the brain.

Recent technological advances in the field of molecular and genetic engineering allow for target specific delivery of light sensitive genes into neuronal membranes, which make them sensitive to optical stimulation. A distinct advantage of this technology is that it provides an ability to optically interrogate with intact neural circuits with millisecond precision in a cell-specific manner, which in turn allows one to probe brain circuits to study the effects of turning specific cells on or off. It also opens doors for devising new therapeutic approaches regulate activity of only malfunctioning neurons and thereby reducing the side effects of otherwise non-cell specific treatment modalities. In this talk, I will demonstrate a particular application of optical stimulation technique for control of neural synchrony in interneuronal networks. Specifically, I will present a closed-loop-feedback control strategy to induce 1:1 in-phase synchrony in a network of coupled interneurons in the presence of heterogeneity in their intrinsic firing activity.