MECHANISM OF FUNCTIONAL PRESYNAPTIC HETEROGENEITY IN CNS

在哺乳动物的罐头中，动作电位 触发神经递质释放(P1)在不同的突触之间差异很大 Synapse。这项研究的目的是弄清其作用机制。 突触之间释放概率差异的基础 终点站。功能突触前异质性的基础将是 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)穿通径突触 在海马片中的突触反应，光学记录 突触前钙瞬变和电子显微镜。主 需要检验的假设是，钙离子内流和 对接的囊泡数量是不同释放特性的基础 侧向穿孔路径末端。 具体目标是： 1.量化外侧和内侧的概率或松动 穿透路径突触，并确定是否有差异n释放 概率分布可以解释成对脉冲的差异 可塑性。 2.确定相关概率的差异是否满足 外侧和内侧穿支路突触的不同 突触前钙内流。 3.确定释放概率的差异是否在 外侧和内侧穿支路突触的不同 一些停靠的小泡。 这些实验将提供有关机制的信息 支配成人罐中兴奋性突触前终末的功能。 这些机制很可能对正常 信息处理，并可在塑料更换过程中更改 伴随着信息存储和病理过程。

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.