HORMONAL REGULATION OF PRESYNAPTIC RELEASE MECHANISMS

该提案的父项目将研究 甲壳类神经肌肉接头处的神经调节激素 特殊离子通道、细胞内钙储备量和第二 肌肉细胞中的信使。协作性提案将利用 来自父项目和分析突触前的录音正在按中 在一份身份不明的日记里。从这一应用程序中，作者推导出 来自多个测量的平均量子含量，以及从它们的 模型计算了释放的概率和数量 已对接/可释放量程。然后，这些变量使他们能够测试 他们的假设是在突触前起作用的荷尔蒙 (如5-羟色胺和肽F1)增加囊泡的动员 而不是释放的概率本身。在 第一个目标，来自Dactyl开启器的细胞外记录的数据 对5赫兹刺激的肌肉进行了分析，得到了稳态平均 多个刺激试验中的量子含量(M)源自 确定突触中屈折形状的算法 作为个体量子的反应。此后，这一分析将被 在沐浴时重复使用激素，在洗澡时再次使用 句号。不同剂量激素对计算结果的影响 释放概率(P)和可释放量子数(N)将为 比较早(第一个50毫秒)和晚(第二个50毫秒) 刺激的目的是分离荷尔蒙对自发性的影响 并引起神经分泌。解决Access的潜在问题 将沐浴测试试剂应用到释放位置，实验将 通过在激素过程中移除记录电极来执行 申请和替换，以供后续录制。第二个目标 将利用频率促进来调查荷尔蒙是否 导致停靠的小泡(N)增加是由于增加 动员或将复员减少到未停靠的池中。这个 稳态，未刺激的动员常数假定为 与受刺激的动员相比微不足道，使 用m-fp倒数图计算这两个参数 确定荷尔蒙对斜率和截距的影响 频率稳态激素效应将通过以下方式建立 换刺激前重复低频刺激 频率最终目标将是测试他们的预期结果在 蒙特卡罗模拟。不同来源的量子含量的结果 模拟频率将作为输入和几个参数 在这个模型中有所不同。这将测试是否更改常量 关于遣散或刺激量子动员到释放地点 更接近于实验结果。这种可能性 激素对释放的非均匀影响在本研究中被考虑 模拟。

The parent project for this proposal will study the effects of neuromodulatory hormones at a crustacean neuromuscular junction on specific ion channels, intracellular calcium stores and second messengers in the muscle cell. The collaborative proposal will utilize recordings from the parent project and analyze presynaptic is in press in an unidentified journal. From this application, the authors derive from multiple measurements the average quantal content, and from their model calculate the probability of release and the number of docked/releasable quanta. These variables then enable them to test their hypothesis that hormones that act presynaptically at this synapse (such as serotonin and peptide Fl) increase mobilization of vesicles to the release site rather than probability of release per se. In the first aim, data from extracellular recordings at the dactyl opener muscle stimulated at 5 Hz are analyzed and the steady state average quantal content (m) in multiple stimulation trials is derived from an algorithm that determines the shape of inflections in the synaptic responses as individual quanta. Thereafter, this analysis will be repeated during bath application of hormones and again during a wash period. The effect of different doses of hormones on calculated probability of release (p) and number of releasable quanta (n) will be compared early (first 50 ms) and late (second 50 ms) following stimulation with the goal of separating hormonal effects on spontaneous and evoked neurosecretion. To address potential problems with access of the bath-applied test reagents to the release site, experiments will be performed by removing the recording electrode during hormone application and replacing for subsequent recordings. The second aim will use frequency facilitation to investigate whether hormonally induced increase in docked vesicles (n) is due to increased mobilization or decrease demobilization to an undocked pool. The steady state, unstimulated mobilization constant is assumed to be negligible compared to the stimulated mobilization, enabling calculation of these two parameters by reciprocal plot of m vs. fp and determining the hormonal effects on slope and intercept at each frequency. Steady state hormone effects will be established by repeated low frequency stimulation before changing stimulation frequency. The final aim will be to test their expected results in a Monte Carlo simulation. Results of quantal content from different simulation frequencies will serve as input and several parameters varied within this model. This will test whether changing the constant of demobilization or stimulated mobilization of quanta to release sites more closely approximates the experimental results. The possibility of non-uniform effects of hormones on release is considered in this simulation.