INDUCTION OF PRESYNAPTIC SPECIALIZATION--ION CHANNELS

描述：(改编自申请者摘要)交流 神经系统中细胞之间的相互作用依赖于 控制神经递质的释放。快速起效和快速终止 诱发的释放表明，特定的蛋白质 参与调节发射器的释放，这是显而易见的 选择性地将突触前蛋白定位于释放部位 在神经细胞与其特定的接触后迅速发生 目标。离子通道(尤其是钙离子和钙激活的钾离子)是 已知在调节递质方面具有至关重要的作用 释放，并且是已知的选择性靶向的蛋白质 到突触前活动区。然而，人们对此知之甚少 神经末梢离子的特性、特性和发展 洋流。申请者建议研究如何诱导 突触前特化(钙和钙激活的钾通道) 表现为沿途形成的递质释放曲张 非洲爪哇脊髓神经元和心肌细胞培养中的突起。 这些是新形成的突触，周围没有胶质细胞。 干扰访问的细胞。使用膜片钳技术， 申请人建议(1)直接描述电流类型 存在于新形成的突触前结构，(2)确定它们的 在递质释放调节中的作用，(3)识别细胞-细胞 调节这些专业化表达的相互作用， 以及(4)确定可诱导 突触前特化的表现。从这些研究中应该 对运动神经末梢Ca~(++)和 钙激活K+通道及其在递质释放和释放中的作用 突触前特化的诱导。

DESCRIPTION: (Adapted from applicant's abstract) Communication between cells in the nervous system is dependent on the precise control of neurotransmitter release. The rapid onset and termination of evoked release indicate that the specific proteins that participate in the regulation of transmitter release, it is apparent that the selective targeting of presynaptic proteins to release sites occurs rapidly following specific contact between a nerve cell and its target. Ion channels (especially Ca++ and calcium-activated K+) are known to be of critical importance in the regulation of transmitter release, and are among the proteins known to be selectively targeted to presynaptic active zones. Little is known, however, about the identity, properties, and development of nerve terminal ionic currents. The applicant proposes to study the induction of presynaptic specialization (Ca++ and calcium-activated K+ channels) expressed at transmitter-releasing varicosities that form along neurites in cultures of Xenopus spinal cord neurons and myocytes. These are newly formed synapses where there are no surrounding glial cells to interfere with access. Using patch clamp techniques, the applicant proposes to (1) characterize directly the types of currents present at newly formed presynaptic structures, (2) determine their role in transmitter release regulation, (3) identify cell-cell interactions that regulate the expression of these specializations, and (4) identify basal lamina components that can induce the expression of presynaptic specialization. From these studies should come a more thorough understanding of motor nerve terminal Ca++ and calcium activated K+ channels, their role in transmitter release and the induction of presynaptic specialization.