SYNAPTIC INTEGRATION AND PLASTICITY IN COMMAND NEURONS

说明此建议的总体目标是了解 小龙虾神经元中突触整合的机制 外侧巨细胞(LG)神经元，这使它成为大规模、 汇聚机械感觉输入。符合检测是一种普遍存在的检测方法 神经系统，并已被证明在双耳定位中起中介作用 鸟类，海马区Hebbian突触的联想学习，40赫兹 哺乳动物大脑皮层和节肢动物大脑中的电振荡，并惊吓 脊椎动物和无脊椎动物的反应。影响疾病的病理 符合检测机制可能会影响学习、双眼深度 知觉、双耳定位和运动性能。而它的 重要性已被广泛认识，但对神经元的了解却很少 符合探测机制。 广泛的初步实验表明，LG对 输入的时间，并将对 与间隔小于0.25毫秒的输入相比，重合输入更重要。 LG的兴奋性输入是通过整流电突触，以及 通过这种突触将输入汇聚到脑内的效应分析 模型突触后神经元表明，电压依赖的电 突触为符合检测提供了一个理想的机制。具体的 目的是定义促进重合的刺激条件 利用LG神经元进行检测，以确定符合机制 影响LG响应的检测，并描述了 初级传入与LG之间的电突触及其如何 为LG的符合探测做出贡献。标准电生理学 并将使用解剖学技术。

DESCRIPTION The general goal of this proposal is to understand the mechanisms of synaptic integration in an identified neuron in crayfish, the Lateral Giant (LG) neuron, that make it a coincidence detector for massive, converging mechanosensory input. Coincidence detection is ubiquitous in the nervous system, and has been shown to mediate binaural localization in birds, associative learning at Hebbian synapses in hippocampus, 40 Hz electrical oscillations in mammalian cortex and arthropod brain, and startle responses in vertebrates and invertebrates. Pathologies that affect coincidence detection mechanisms may affect learning, binocular depth perception, binaural localization, and motor performance. While its importance is widely recognized, little is known about the neuronal mechanisms of coincidence detection. Extensive preliminary experiments showed that LG is extremely sensitive to the timing of inputs, and will give substantially larger responses to coincident inputs than to inputs which are separated by less than 0.25 ms. LG's excitatory inputs are through rectifying electrical synapses, and analysis of the effect of converging inputs through such synapses onto a model postsynaptic neuron indicated that voltage-dependent electrical synapses provide an ideal mechanism for coincidence detection. The specific aims are to define the stimulus conditions that promote coincidence detection by the LG neuron, to identify the mechanisms of coincidence detection that affect LG's response, and to describe the properties of the electrical synapses between primary afferents and LG, and how they contribute to coincidence detection by LG. Standard electrophysiological and anatomical techniques will be used.