INDUCTION OF PRESYNAPTIC SPECIALIZATION--ION CHANNELS

描述：（改编自申请人摘要）通信 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。 快速发作和终止 这表明， 参与调节发射器的释放，很明显， 突触前蛋白选择性地定位在释放位点， 在神经细胞与其细胞之间的特异性接触后迅速发生。 目标 离子通道（尤其是Ca++和钙激活的K+） 已知在变送器的调节中至关重要 释放，并且是已知被选择性靶向的蛋白质之一 到突触前活跃区 然而，人们对它知之甚少。 神经末梢离子的鉴定、性质和发展 水流 申请人建议研究 突触前特化（Ca++和钙激活的K+通道） 表达为释放发射体的静脉曲张沿着 非洲爪蟾脊髓神经元和肌细胞培养物中的神经突。 这些是新形成的突触，周围没有神经胶质 细胞干扰访问。 采用膜片钳技术， 申请人提出（1）直接表征电流的类型 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 调节这些特化表达的相互作用， 和（4）鉴定可以诱导细胞凋亡的基底层成分。 突触前特化的表达。 这些研究应该 对运动神经末梢Ca ~（++）有了更深入的了解， 钙激活的K+通道，它们在递质释放中的作用， 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.