9309986 Hooper This proposal outlines a combination of electrophysiological experiments and computer simulations on a small, well described invertebrate distributed neural network (the lobster pyloric network) aimed at elucidating these design principles. The pyloric network contains neurons with long lasting active properties, can assume multiple functional configurations, and produces a rhythmic multiphase output. The network has a remarkable dynamic property that may be analogous to the ability to process inputs over a wide temporal range: it maintains constant phase and duty cycle relationships within the pattern as pattern cycle frequency changes. The experimental advantages of this preparation allow all the network's neurons to be individually characterized, and the network to be simulated on the level of the individual conductances of its neurons. It is thus a excellent preparation in which to study the questions outlined above. This work will show how cellular and synaptic properties lead to emergent network functional properties, and elucidate fundamental mechanisms of dynamic regulation in distributed neural networks.***
