The function of glycine in modulation of cone visual sensitivity

本项目研究甘氨酸在视网膜锥视敏感性微调中的潜在作用。锥状光感受器在明亮的光线下敏感，在昏暗的光线下不太敏感。在昏暗的光线条件下，闪烁的光可以增强视锥细胞的视敏度，视锥细胞视敏度的改变是视网膜内发生的神经调节过程。这种锥体敏感性改变背后的机制尚不清楚。初步研究表明，甘氨酸作为一种神经递质在视网膜中释放，导致在昏暗闪烁的光线下锥体信号的增加。提出的研究目标是发现在昏暗光线下从锥体到二级视网膜神经元的神经传递调节的新机制。最先进的技术，包括电生理记录和荧光成像，将用于研究闪烁光诱导的甘氨酸释放在视网膜神经网络中的影响，以及甘氨酸在增强锥体信号传导到二级神经元中的作用。实验将以蝾螈视网膜作为研究视网膜网络调制的常用模型系统。该项目的结果将有助于更好地理解神经网络的功能相互作用及其行为适应。在电生理学、体内成像和免疫细胞化学等技术要求较高的领域，也将对本科生和研究生进行培训。这项研究和更广泛的影响将使在这些技术要求很高的科学领域培训未来科学家的重要使命成为可能，其中许多科学家来自代表性不足的人口。同时，这项工作将促进佛罗里达州南部老年人终身学习计划的教与学。

This project studies the potential role of glycine in fine-tuning cone visual sensitivity within retinas. Cone photoreceptors are sensitive in bright light and less sensitive in dim light conditions. Flickering light can enhance cone visual sensitivity in dim light conditions, and changing cone visual sensitivity is a neural modulatory process occurring within retina. The mechanism behind this altered cone sensitivity is unknown. Preliminary studies show that glycine released as a neurotransmitter in the retina results in an increase of cone signaling in dim flickering light. The goal of the proposed research is to discover the novel mechanism(s) involved in modulation of neurotransmission from cones to second-order retinal neurons in dim light. State-of-the-art techniques, including electrophysiological recording and fluorescence imaging, will be used to investigate the affects of flickering light-induced glycine release in the retinal neural network and the action of glycine in enhancing cone signaling to the second-order neurons. The experiments will be carried out in salamander retinas commonly used as a model system to study retinal network modulation. The results from the proposed project will serve for better understanding the functional interactions of neural networks and their behavioral adaptations. There will also be training of undergraduate and graduate students in the technically demanding areas of electrophysiology, in vivo imaging, and immunocytochemistry. This research and broader impacts will enable the important mission of training future scientists, many from underrepresented populations, in these technically demanding areas of science. Also, this work will promote teaching and learning in the lifelong learning program for seniors in southern Florida.