NEUROBIOLOGY OF IDENTIFIED PEPTIDERGIC NEURONS

该项目的长期目标是在 细胞水平控制相互作用的机制 在肽能神经元和其他细胞之间。神经肽 对身体的许多组织都有深远的影响，包括神经 从低级无脊椎动物到人类的大多数动物的系统。 它们扮演着各种各样的生理角色，从 神经递质转化为神经激素。中国人的神经系统 飞蛾，Manduca sexta，提供了一个特别吸引人的模型 电生理、内分泌、 可以进行生化和发育实验 方便地在体内和体外单独识别的 肽能神经元。神经肽的细胞作用可以 因此在这种无脊椎动物中被更精确地跟踪 系统比目前的任何脊椎动物制剂都要好，其中 神经肽的细胞研究已被证明是困难的。 这项研究的主要焦点将是6个单独确定的 该蛾体内的肽能神经元含有两个新的 神经肽。我们之前已经证明了这两个 被称为心脏加速肽(CAP)的多肽发挥作用 成人羽化过程中重要的心脏调节作用 在飞蛾中的行为。这项提案将利用 多学科方法检查电生理和 CAP功能的生化方面。 人们对其电生理机制知之甚少 调节含肽神经元的活动。 激活的CAP神经元的细胞内记录将是 在成虫羽化行为期间获得。在这些实验中， 单个CAP神经元的电活动将直接 与多肽的释放量有关。实验，其中 CAP神经元的神经元输入被识别，将 提供了关于神经控制的关键新信息 肽能神经元和肽的释放。 上限对其目标的行动模式也将是 探索过了。这些帽子的电生理效应将是 对单独分离的心肌纤维的研究 常规和电压钳位记录。生物化学 CAP对心脏的作用基础也将由 测定CAP诱导的细胞内钙离子水平的变化 环核苷酸和/或肌醇磷酸盐。

The long-term goal of this project is to understand at the cellular level the mechanisms which control the interactions between peptidergic neurons and other cells. Neuropeptides have profound effects on many body tissues including the nervous system of most animals from lower invertebrates to humans. They perform a wide variety of physiological roles ranging from neurotransmitter to neurohormone. The nervous system of the moth, Manduca sexta, provides a particularly attractive model system in which electrophysiological, endocrinological, biochemical and developmental experiments can be performed conveniently in vivo and in vitro on individually identifiable peptidergic neurons. The cellular action of neuropeptides can therefore be followed with greater precision in this invertebrate system than in any present vertebrate preparation, where cellular studies on neuropeptides have proven difficult. The primary focus of this study will be 6 individually identified peptidergic neurons in the moth which contain two novel neuropeptides. We have previously shown that these two peptides, known as cardioacceleratory peptides (CAPs), play important cardioregulatory roles during adult emergence behavior in the moth. This proposal will utilize a multidisciplinary approach to examine electrophysiological and biochemical aspects of CAP function. Little is known about the electrophysiological mechanisms that regulate the activity of peptide-containing neurons. Intracellular recordings from active CAP neurons will be obtained during adult emergence behavior. In these experiments, electrical activity in individual CAP neurons will be directly related to the amount of peptide released. Experiment, in which the neuronal inputs to the CAP neurons are identified, will provide crucial new information on the neural control of peptidergic neurons and peptide release. The mode of action of the CAPs on their targets will also be explored. The electrophysiological effects of the CAPs will be studied in individually dissociated heart muscle fibers using conventional and voltage clamp recordings. The biochemical basis of CAP action on the heart will also be investigated by measuring CAP induced changes in the intracellular levels of cyclic nucleotides and/or inositol phosphates.