MECHANISM OF FUNCTIONAL PRESYNAPTIC HETEROGENEITY IN CNS

在哺乳动物CANS中，动作电位将 触发神经递质释放（P1）从突触到 突触 本研究的目的是确定其机制 突触之间释放概率的差异 terminals. 功能性突触前异质性的基础是 通过比较外侧（促进;低P）和内侧（非 使用全细胞记录促进;高P）穿通通路突触 海马切片中突触反应的光学记录， 突触前钙瞬变和电子显微镜检查。 主要 待检验假设是钙内流的差异和 停靠囊泡的数量是不同释放特性的基础， 侧穿通路终端。 具体目标是： 1.量化外侧和内侧的可能性或释放 穿孔路径突触，并确定是否有差异n释放 概率沿着可以解释成对脉冲的差异 可塑性。 2. 为了确定相关概率的差异是否 外侧和内侧穿通通路突触的产生是由于 突触前钙内流 3. 为了确定释放概率的差异， 外侧和内侧穿通通路突触的产生是由于 一些对接的囊泡。 这些实验将提供有关机制的信息， 支配成年CANS兴奋性突触前末梢的功能。 这些机制可能对正常的 信息处理，并可能在塑料变化过程中改变， 伴随着信息储存和病理过程。

In the mammalian CANS, the probability that an action potential will trigger neurotransmitter release (P1) varies widely form synapse to synapse. The aim of this research is to ascertain the mechanisms underlying the differences in release probability between synaptic terminals. The basis of functional presynaptic heterogeneity will be studied by comparing lateral (facilitating; low P) and medial (non- facilitating ; high P) perforant path synapses using whole-cell recording of synaptic responses in hippocampal slices, optical recording of presynaptic calcium transients, and electron microscopy. The main hypothesis to be tested are that differences in calcium influx and the number of docked vesicles underlie the different release properties of lateral perforant path terminals . the specific aims are: 1. To quantify the probability or release at lateral and medial perforant path synapses, and determine if a difference n release probability along can account for the difference in paired-pulse plasticity. 2. To determine if the difference in the probability of relate sat lateral and medial perforant path synapses results from a difference in presynaptic calcium influx. 3. To determine if the difference in the probability of release at lateral and medial perforant path synapses results from a difference in a number of docked vesicles. These experiments will provide information about the mechanisms that dictate function at excitatory presynaptic terminals in the adults CANS. These mechanisms are likely to be critically important for normal information processing, and may be altered during plastic changes that accompany information storage and pathological processes.