? The long-term goal of these studies is to understand the mechanism of spontaneous retinal wave in developing retina. Although the spatiotemporal aspect of retinal wave has been widely studied, little is known about the mechanism underlying the initiation, propagation, and termination. Recently from our lab, it is shown that cholinergic amacrine cells (starburst) display rhythmic burst of sodium and calcium spikes that are correlated with stage II retinal waves. The rhythmic spike in starburst cell still persists in the presence of neurotransmitter blockers that terminate retinal wave. These burst activities are followed by after hyperpolarization potential that set the interval of wave suggesting that starburst cells possess intrinsic property to pace the retinal wave during development. The proposal below addresses questions central to understanding how starburst cell in the mammalian retina operates spontaneous wave: 1) What is the cellular mechanism responsible for pace-making activity in stage II wave? 2) What is the relationship between pace-making and retinal wave? 3) Does bipolar cell, the other type of interneuron, also possess pace-making activity in stage III wave? Answer to these questions will lead to an understanding in the development of neurocircuitry of the retina. ? ? ?
