Significance of Synaptic Dynamicsin Oscillatory Neuronal Circuits

PI: NADIM

Abstract

Rhythmic motor patterns such as walking, swimming and digestion of food are fundamental behaviors in all living animals. These behaviors originate in electrical signals produced by complex networks of the central nervous system. The underlying mechanisms that generate and coordinate these electrical rhythmic patterns are only now beginning to be understood. We study rhythmic pattern generation in a small neuronal circuit, the pyloric network of the lobster Panulirus interruptus. This network is responsible for controlling the muscles involved in chewing and filtering of food in the lobster. This network is an ideal model system for understanding rhythmic motor activity due to its experimental accessibility and small number of neurons.

We focus on understanding how the pyloric network output is shaped by the dynamic behavior of its synapses. We record neuronal waveforms during an ongoing pyloric rhythm in vitro. We then play back these realistic waveforms into the network in

controlled conditions with the aid of a computer. The synaptic response to these waveforms are analyzed and used to build computational models. These model synapses are, in turn, interfaced with the biological network in real time and thus tested directly in an experimental setting. The goal of this work is to further our understanding of the neural basis of behavior by building realistic models that accurately reproduce the behavior.