Is the input to a GABAergic synapse the sole asymmetry in turtle's retinal directional selectivity?

Author:

Smith Randall D.,Grzywacz Norberto M.,Borg-Graham Lyle J.

Abstract

AbstractWe examined the effects of picrotoxin and pentylenetetrazol (PTZ) on the responses to motions of ON-OFF directionally selective (DS) ganglion cells of the turtle's retina. These drugs are antagonists of the inhibitory neurotransmitter GABA. For continuous motions, picrotoxin markedly reduced the overall directionality of the cells. In 21% of the cells, directional selectivity was lost regardless of speed and contrast. However, other cells maintained their preferred direction despite saturating concentrations of picrotoxin. And in most cells, loss, maintenance, or even reversal of preferred and null directions could occur as speed and contrast were modulated. In 50% of the cells, reversal of preferred and null directions occurred at some condition of visual stimuli. However, picrotoxin did not tend to alter the preferred-null axis for directional selectivity. For apparent motions, picrotoxin made motion facilitation, which normally occurs exclusively in preferred-direction responses, to become erratic and often occur during null-direction motions. Finally, PTZ had effects similar to picrotoxin but with less potency. The results in this paper indicated that models of directional selectivity based solely on a GABAergic implementation of Barlow and Levick's asymmetric-inhibition model do not apply to the turtle retina. Alternative models may comprise multiple directional mechanisms and/or a symmetric inhibitory one, but not asymmetric facilitation.

Publisher

Cambridge University Press (CUP)

Subject

Sensory Systems,Physiology

Cited by 24 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. Emerging computational motifs: Lessons from the retina;Neuroscience Research;2023-11

2. Flexible Neural Hardware Supports Dynamic Computations in Retina;Trends in Neurosciences;2018-04

3. The Role of Acetylcholine and Its Receptors in Retinal Processing☆;Reference Module in Neuroscience and Biobehavioral Psychology;2017

4. Pharmacological study of direction selectivity in the archer fish retina;Journal of Integrative Neuroscience;2015-12

5. GABAergic neurotransmission and retinal ganglion cell function;Journal of Comparative Physiology A;2015-02-06

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3