THE STRUCTURE OF MITOCHONDRIA IN ROD AND CONE PHOTORECEPTORS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 这些研究的总体目标是发展一个全面的结构和功能的理解杆小球和锥椎弓根带状突触终端。脊椎动物光感受器是非尖峰神经元，在黑暗中维持带状突触的持续去极化和神经递质释放，并产生光依赖性分级超极化反应。视杆细胞以高保真度传输单光子响应，而视锥细胞胞吐作用更快。这是由于突触前光感受器线粒体、内质网、质膜Ca ~（2+）-ATP酶和Na ~+-Ca ~（2+）交换体之间的代谢偶联和相互作用的差异造成的。我们正在确定感光突触中代谢偶联的机制。 激光扫描共聚焦显微镜（LSCM），电子显微镜（EM）和三维电子断层扫描（ET）研究的具体目标有三个方面。首先是确定线粒体，ER，PMCA和NCX在视网膜中，特别是在感光突触末梢中的细胞分布和空间相互关系。第二个是确定细胞和亚细胞ATP和Ca 2+的调节机制是否不同的视杆小球和锥蒂突触终末。第三个目标是确定我们的结果在杆和锥突触末端生物能量学，Ca 2+稳态和神经递质释放的功能意义。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overall goal of these studies is to develop a comprehensive structural and functional understanding of rod spherule and cone pedicle ribbon synaptic terminals. Vertebrate photoreceptors are nonspiking neurons that maintain sustained depolarization and neurotransmitter release from ribbon synapses in darkness and produce light-dependent graded hyperpolarizing responses. Rods transmit single photon responses with high fidelity, whereas cone exocytosis is faster. These come from differences in metabolic coupling and cross-talk between presynaptic photoreceptor mitochondria, endoplasmic reticulum (ER), plasma membrane Ca2+-ATPase (PMCA) and Na+-Ca2+ exchanger (NCX). We are determining the mechanisms of metabolic coupling in photoreceptor synapses. The specific aims of the laser scanning confocal microscopy (LSCM), electron microscopy (EM) and three-dimensional electron tomography (ET) studies are threefold. The first is to determine the cellular distribution and spatial interrelation of mitochondria, ER, PMCA and NCX in the retina and especially in the photoreceptor synaptic terminals. The second is to determine if the cellular and subcellular ATP and Ca2+ regulatory mechanisms differed between rod spherule and cone pedicle synaptic terminals. The third goal is to determine the functional significance of our results in relation to rod and cone synaptic terminal bioenergetics, Ca2+ homeostasis and neurotransmitter release.