GABA-ERGIC MECHANISMS OF THE DISTAL RETINA

有令人信服的证据表明，特定类别的视网膜 水平细胞利用抑制性氨基酸GABA作为 神经递质，而GABA在建立 中心-环绕对抗性是接受场的特征 视网膜神经元的特性。载体介导的GABA转运 水平细胞似乎是这一过程的重要组成部分， 并可能同时服务于吸收和释放 神经递质。全细胞记录方法的出现使 允许以前所未有的方式检查这样的运输过程 使用电生理技术进行详细说明。所描述的实验 旨在利用这种技术来检查 视网膜水平细胞运输GABA的潜在机制， 并包括对导致摄取的离子机制的研究， 转运的药理特性及其调节作用 通过神经调节剂多巴胺进行运输。问题是，是否 载体介导的GABA从水平细胞外流是产生电的 也将进行探索。最后，GABA对视杆细胞的影响 将检查光感受器和杆状双极细胞，以便 确定作为GABA突触后靶点的细胞 由水平单元格释放。这项研究应该提供更大的 对GABA在血管形成中的作用的认识 包围部分视觉神经元的感受野。

There is compelling evidence to suggest that specific classes of retinal horizontal cells utilize the inhibitory amino acid GABA as a neurotransmitter, and that GABA plays a key role in establishing the center-surround antagonism that characterizes the receptive field properties of retinal neurons. Carrier-mediated transport of GABA by horizontal cells appears to be an essential component of this process, and serves perhaps both in the uptake and release of the neurotransmitter. The advent of the whole-cell recording method has permitted such transport processes to be examined in unprecedented detail using electrophysiological techniques. The experiments described in this proposal are designed to utilize such techniques to examine the mechanisms underlying the transport of GABA by retinal horizontal cells, and include a study of the ionic mechanisms responsible for uptake, the pharmacological properties of the transport, and the modulation of transport by the neuromodulator dopamine. The question of whether carrier-mediated efflux of GABA from horizontal cells is electrogenic will also be explored. Finally, the effects of GABA on rod photoreceptors and rod bipolar cells will be examined in order to identify the cells that serve as the postsynaptic target for GABA released by horizontal cells. This research should provide a greater understanding of the role that GABA plays in the formation of the surround portion of the receptive fields of visual neurons.