Analysis of visuo-motor transformation process in the tecto-reticulo-spinal system.

顶盖-网状-脊柱系统中视觉-运动转换过程的分析。

基本信息

批准号：
08458266
负责人：
ISA Tadashi
金额：
$ 4.67万
依托单位：
National Institute for Physiological Sciences, Okazaki National Research Institutes
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08458266/
关键词：
attention express saccades superior colliculus acetylcholine nicotine monkey rats サル脳スライスニコチン

项目摘要

Reaction time of visually guided saccadic eye movements can be a good measure to monitor the state of spatial attention.When our attention on a fixation point in the center of our vesual field is desengaged, and becomes diffused on the periphery of the visual field, extremely short-latency saccadic eye movements (70-100msec after presentation of the target), called express saccades, occur to targets presented in the periphery. We have hypothesized that the express saccades take place when the visual input directly activate the motor output system by taking the short-cut pathway in the central nervous system, and the short-cut pathway is that from the superficial layr to the deeper layrs of the superior colliculus (SC). Furthermore, we hypothesized that acetylcholinergic system plays the dey role in facilitating the signal transmission in the SC to execute the express saccades.To prove these hypotheses, we investigated (1) signal transmission in the local circuit of the SC and function … More of acetylcholinergic input by using slice preparations obtained from rats, and (2) effect of injection of acetylcholine-related substance (especially nicotine) into the SC on saccadic reaction time.(1) We have clarified that there exists an excitatory pathway from the optic tract (OT) to the intermediate layr (SGI) of the SC via neurons in the superficial (SGS) and optic (SO) layrs by suing whole cell patch clamp recording technique in the SC slices obtained from rats. The excitatory transmission in mediated by both AMPA and NMDA type glutamate receptors, and usually under strong suppression by the GABAA system. Nicotine induces inward currents in neurons in the intermediate layr of the SC,by direct action on the nicotinic receptors in these neurons. Furthermore, application of nicotine dramatically enhanced the signal transmission in the OT-SGS/SO-SGI pathway, which was attriuted to the depolarization of the SGI neurons by nicotine.(2) When nicotin (1-10mM,1mul) is injected into the SGI of the monkey SC (n=2), frequency of express saccades (latency below 100 msec) dramatically increased. The mechanisms was supposed to be bypassing the short-cut pathway from the SGS/SO to the SGI neurons by depolarizing the SGI neurons.We are further planning to investigate the effect of acetylcholine antagonists on occurrence of express saccades and activity of cholinergic neurons in the pedunclulopontine tegmental nucleus, which is the input origin of the cholinergic fibers innervating the SC during visually guided saccade task. Less

视觉引导的扫视眼球运动的反应时间可以很好地衡量空间注意力的状态。当我们对位于视野中心的注视点的注意力脱离并分散到视野的外围时，短延迟眼跳（目标呈现后 70-100 毫秒），称为快速眼跳，出现在外围呈现的目标上。快速眼跳是视觉输入通过中枢神经系统中的捷径直接激活运动输出系统时发生的，该捷径是从上丘（SC）浅层到深层的路径此外，我们还发现乙酰胆碱能系统在促进 SC 中的信号传输以执行快速眼跳方面发挥着重要作用。为了证明这些假设，我们研究了 (1) SC 局部电路中的信号传输和功能…通过使用从大鼠获得的切片制剂输入更多的乙酰胆碱能物质，以及（2）将乙酰胆碱相关的（尤其是尼古丁）注射到 SC 中对扫视反应时间的影响。（1）我们已经阐明存在从通过使用全细胞膜片钳记录，通过浅层 (SGS) 和视 (SO) 层中的神经元从视束 (OT) 到 SC 的中间层 (SGI)在从大鼠获得的 SC 切片中，兴奋性传递由 AMPA 和 NMDA 型谷氨酸受体介导，通常在 GABAA 系统的强烈抑制下，通过直接作用在 SC 中间层的神经元中诱导内向电流。此外，尼古丁的应用显着增强了 OT-SGS/SO-SGI 通路中的信号传递，这导致了神经元的去极化。 (2)当尼古丁(1-10mM,1μl)注射到猴子SC(n=2)的SGI中时，快速眼跳(潜伏期低于100毫秒)的频率显着增加。推测其机制。通过去极化SGI神经元来绕过从SGS/SO到SGI神经元的捷径。我们正在进一步计划研究乙酰胆碱拮抗剂的作用脚桥被盖核中快速眼跳的发生和胆碱能神经元的活动，脚桥被盖核是视觉引导眼跳任务期间支配 SC 的胆碱能纤维的输入来源。