Function and Mechanism of Neural Spike Coherence in Drosophila

描述（由申请人提供）：整个大脑的神经元组表现出连贯（相关或同步）活动。这一显著的观察结果使许多人假设，神经系统对连贯尖峰的解释可能与非连贯尖峰不同。然而，由于缺乏操纵尖峰相干性的工具，这一假设很难进行实证检验。另一个障碍是缺乏一种体内制备方法，人们可以从已知连接的神经元中记录。我建议使用遗传学、电生理学、药理学和行为学技术来研究果蝇嗅觉系统中穗连贯性的功能。我将首先测量嗅觉受体神经元之间连贯活动的时间尺度，并开发一种遗传技术来操纵连贯性。然后，我将系统地改变嗅觉受体神经元的相干性，同时测量突触后二级神经元的尖峰，以了解相干性如何影响突触后尖峰响应的速度和幅度。然后，我将确定局部抑制如何影响突触后神经元对相干性的敏感性。最后，我将进行行为测量，以询问神经对连贯性的敏感性是否限制了行为敏感性。本研究将有助于阐明大脑中连贯活动的功能和机制及其对行为的重要性。

DESCRIPTION (provided by applicant): Groups of neurons throughout the brain exhibit coherent (correlated or synchronized) activity. This remarkable observation has led many to hypothesize that coherent spikes may be interpreted by the nervous system differently from non-coherent spikes. This hypothesis, however, has been difficult to test empirically because of the lack of tools to manipulate spike coherence. An additional obstacle has been the lack of an in vivo preparation where one can record from neurons whose connectivity is known. I propose to study the function of spike coherence in the olfactory system of the fruit fly using genetic, electrophysiological, pharmacological, and behavioral techniques. I will first measure the timescale of coherent activity among olfactory receptor neurons and develop a genetic technique to manipulate coherence. I will then systematically vary the coherence in olfactory receptor neurons while measuring spikes in postsynaptic second-order neurons to ask how coherence affects the speed and magnitude of the postsynaptic spiking response. I will then determine how local inhibition influences the sensitivity to coherence of the postsynaptic neuron. Finally, I will make behavioral measurements to ask whether the neural sensitivity to coherence limits behavioral sensitivity. This study will help elucidate the function and mechanism of coherent activity in the brain and its importance for behavior.