Cerebellar Circuitry and Plasticity in an Electric Fish

小脑的神经回路似乎相对简单和明确，但 这个电路执行的计算是不被理解的。此外，突触的形式 小脑中的可塑性可能与运动学习有关，但 关于这种可塑性的关键问题仍然没有答案。建议的目标是 这项研究是通过对小脑回路和可塑性的研究来解决基本问题的 罗非鱼特有的小脑。小脑的两个特点使它变得更好。 适用于解决这些问题：1)浦肯氏细胞和小脑输出细胞(小脑细胞 哺乳动物的细胞核)在桑鱼中彼此相邻，这使得有可能在 在这两种细胞类型之间的重要突触上的整合和可塑性 在哺乳动物身上完成的。2)上行光纤和平行光纤输入的端接区域 在胚胎动物中，浦肯氏细胞明显且分离良好，而在哺乳动物中则不然。这 分离有助于确定两个树突区域之间的本质差异 以及确定两个输入如何相互作用以产生突触可塑性。 该项目有两个具体的目标：1)确定基本的突触和内在生理学 目的：(1)确定桑鱼的小脑输出细胞；(2)确定 桑鱼平行纤维和浦肯野细胞突触的可塑性。主要方法是 将在体外切片中进行全细胞斑块记录，并结合记录的元素进行标记 形态鉴定。

The neuronal circuitryof the cerebellum appears to be relativelysimple and well defined, but the computation performed by this circuitry is not understood. In addition, forms of synaptic plasticityhave been defined in the cerebellum that may be responsiblefor motor learning, but criticalquestions regarding this plasticityare still unanswered. The objective of the proposed research is to address fundamental issues cerebellar circuitry and plasticitythrough a study of the unique cerebellum of mormyridelectricfish. Two features of the mormyrid cerebellum make itwell suitedto address these issues: 1) Purkinjecells and cerebellar output cells (cells of the cerebellar nuclei in mammals) are adjacent to each other in mormyridfish, making possibleexperiments on integrationand plasticityat the important synapse between these two cell types that can not be done in mammals. 2) The regionsof terminationfor climbingfiber and parallel fiber inputs on Purkinjecellsare distinctand well separated in the mormyrid but not inthe mammal. This separation facilitates the determination of intrinsicdifferences between the two dendritic regions and the determination of how the two inputs interactto generate synaptic plasticity. The project has two Specific Aims: 1) to determine the basic synaptic and intrinsicphysiologyof Purkinjeand cerebellar output cells in mormyrid electricfish; and 2) to determine the types of plasticityat parallel fiber and Purkinje cellsynapses in mormyrid electricfish. The primary method will be whole-cell patch recordingin in vitro slices, combined with labelingof recorded elements for morphologicalidentification.