GRADED SYNAPTIC TRANSMISSION IN LOCAL NEURAL CIRCUITS

拟议研究的目的是增加我们对 局部回路神经元使用的突触机制，特别是， 为了研究分级突触传递在发放、局部发放和传递中的作用， 回路神经元。 当前的目标是了解 分级的、棘波诱发的和神经调质突触的贡献 传输到一个小的神经网络的功能， 龙虾和螃蟹的口胃神经节。 在此之前的几年里， 格兰特，生理特性和一些潜在的机制， 的分级突触传递。 在下一个资助期， 重点将放在神经元结构和突触的解剖学方面。 组织，并对相关的生理测量电压 在神经元内和相连的细胞对之间传播。 的方法 包括：细胞内记录和染料注入，电压 钳夹、免疫染色和共聚焦显微镜。 口胃神经元具有串联的突触结构， 树突和分级的突触性质，似乎是理想的 为区域计算而设计。 然而，到目前为止， 他们在区域内计算，不清楚他们如何避免这样做。 神经调质可以在功能上重新连接突触连接， 口胃神经节但我们不知道它们在哪里起作用 因此，在本发明中， 关于这些神经元的突触组织及其 电紧张性是必不可少的，如果我们要了解 每个神经元对这个局部神经元功能的贡献 电路. 提供这些信息是本提案的目标。 这些神经元在结构上与不易接近的丘脑神经元相似 在人类和口胃运动网络作为一个模型， 节律性运动功能，包括行走和咀嚼。 通过增加我们 了解这个模型系统是如何工作的，我们可能会得到一些线索， 是常见运动病理的基础， 恢复正常功能。

The objective of the proposed research is to increase our understanding of the synaptic mechanisms used by local circuit neurons and, in particular, to study the function of graded synaptic transmission in spiking, local circuit neurons. The immediate objective is to understand the contributions of graded, spike-evoked, and neuromodulator synaptic transmission to the functioning of a small neural network, the stomatogastric ganglion of lobsters and crabs. In earlier years of this grant, the physiological properties and some of the underlying mechanisms of graded synaptic transmission were described. In the next grant period, the focus will be on anatomical aspects of neuron structure and synaptic organization, and on correlated physiological measurements of voltage spread both within a neuron and between connected cell pairs. The methods to be used include: intracellular recording and dye injection, voltage clamp, immunostaining, and confocal microscopy. Stomatogastric neurons have the serial synaptic structure, extended dendrites, and graded synaptic properties that appear to be ideally designed for regional computation. However, so far there is no evidence that they regionally compute and it is not clear how they avoid doing so. Neuromodulators can functionally rewire the synaptic connections in the stomatogastric ganglion, but we don't known where they act. Thus, information on the synaptic organization of these neurons and on their electrotonic properties is essential if we are to understand the contribution made by each neuron to the functioning of this local neural circuit. Providing that information is the objective of this proposal. These neurons are structurally similar to less accessible thalamic neurons in humans and the stomatogastric motor network serves as a model for human rhythmic motor functions, including walking and chewing. By increasing our knowledge of how this model system works, we may gain clues to what underlies common motor pathologies and to how the system can be readjusted to restore normal function.