SYNAPTIC INTEGRATION AND PLASTICITY IN COMMAND NEURONS

描述本提案的总体目标是了解 小龙虾中一个已鉴定的神经元的突触整合机制， 外侧巨（LG）神经元，使其成为大规模， 会聚机械感觉输入。 巧合检测在 神经系统，并已被证明介导双耳定位， 鸟类，海马Hebbian突触的联想学习，40 Hz 哺乳动物皮层和节肢动物大脑的电振荡， 脊椎动物和无脊椎动物的反应。 病理影响 重合检测机制可能会影响学习、双眼深度 感知、双耳定位和运动性能。 而其 重要性被广泛认识，但对神经元的了解甚少。 符合检测机制。 广泛的初步实验表明，LG对 输入的时间，并将给予实质上更大的反应， 同步输入比间隔小于0.25 ms的输入更容易识别。 LG的兴奋性输入是通过整流电突触， 分析通过这种突触将输入会聚到 模型突触后神经元表明，电压依赖性电 突触为重合检测提供了理想的机制。 具体 目的是定义促进巧合的刺激条件 通过LG神经元的检测，以确定重合的机制 检测影响LG的响应，并描述的属性， 初级传入和LG之间的电突触，以及它们如何 有助于LG的符合检测。标准电生理 和解剖技术。

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.