Synaptic Plasticity in Hebbian Cell Assemblies

描述（由申请人提供）：Donald O.赫布设想用细胞集合体--一个神经元按固定顺序放电的小网络--来代表记忆痕迹。这些细胞组装体被认为是在许多实验制剂中观察到的持续活动模式的基础。然而，目前还不知道这些组件是如何从一群发育中的神经元中从无到有地发展出来的，以及组件一旦出现如何保持稳定。这些问题中的第一个直接关系到记忆痕迹如何在大脑中出现。第二个问题与癫痫直接相关，癫痫是一种以不稳定、过度兴奋的神经元网络为特征的病理学。大鼠海马培养为研究这些问题提供了一个模型系统。除了是一个高度易处理的系统外，它还支持反射电路的自发发展，这是细胞组装的标志。使用这个系统结合穿孔膜片钳记录，我将研究活动依赖性突触可塑性和赫布细胞组装之间的相互关系。

DESCRIPTION (provided by applicant): Donald O. Hebb conceived of the cell assembly - a small network whose neurons fire in stereotyped sequences - to represent a memory trace. These cell assemblies are believed to underlie persistent activity patterns observed in many experimental preparations. However, it is unknown how these assemblies develop ex nihilo from a population of developing neurons, and how an assembly can retain stability once it emerges. The first of these questions bears directly on how memory traces can emerge in the brain. The second question is of direct relevance to epilepsy, a pathology characterized by unstable, hyperexcitable neuronal networks. Rat hippocampal culture provides a model system for studying these questions. In addition to being a highly tractable system, it supports the spontaneous development of reverberatory circuits, a hallmark of cell assemblies. Using this system in combination with perforated patch clamp recordings, I will examine the reciprocal relationship between activity-dependent synaptic plasticity and Hebbian cell assemblies.