MODIFICATION OF SACCADIC EYE-MOVEMENTS BY GABA-RELATED SUBSTANCES .1. EFFECT OF MUSCIMOL AND BICUCULLINE IN MONKEY SUPERIOR COLLICULUS
MODIFICATION OF SACCADIC EYE-MOVEMENTS BY GABA-RELATED SUBSTANCES .1. EFFECT OF MUSCIMOL AND BICUCULLINE IN MONKEY SUPERIOR COLLICULUS
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DOI：
10.1152/jn.1985.53.1.266
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发表时间：
1985-01-01
影响因子：
2.5
通讯作者：
WURTZ, RH
中科院分区：
文献类型：
--
作者：
HIKOSAKA, O;WURTZ, RH
黑质网状部（SNr）的细胞紧张性抑制上级丘（SC）中间层的眼跳相关细胞。在扫视视觉或记忆中的目标之前，SNr中的细胞短暂地减少这种抑制，允许SC细胞爆发尖峰信号，这反过来又导致扫视眼球运动的启动。由于这种抑制可能是由γ介导的，氨基丁酸（GABA），通过将GABA激动剂（蝇蕈醇）或GABA拮抗剂（荷包牡丹碱）注射到上级丘中来测试该假设，并测量对视觉或记忆目标的扫视眼球运动的影响。蝇蕈醇的注射选择性地抑制扫视到注射部位附近的细胞的运动场。受影响的区域随着时间的推移而扩大，从而表明蝇蕈醇在SC中的扩散;该区域从未包括另一半场，这表明扩散仅限于一个SC。其中一只猴子无法对受影响的区域进行任何扫视。与蝇蕈醇相反，荷包牡丹碱的注射促进了扫视的启动。GABA显然对SC具有强大的影响;增强或减少GABA抑制改变扫视眼球运动的执行。SC除了影响扫视眼动的潜伏期和准确性之外，还影响扫视眼动的速度。
Cells in the substantia nigra pars reticulata (SNr) tonically inhibit saccade-related cells in the intermediate layers of the superior colliculus (SC). Before saccades to visual or remembered targets, cells in SNr briefly reduce that inhibition, allowing a burst of spikes of SC cells that, in turn, leads to the initiation of a saccadic eye movement. Since this inhibition is likely to be mediated by .gamma.-aminobutyric acid (GABA), this hypothesis was tested by injecting a GABA agonist (muscimol) or a GABA antagonist (bicuculline) into the superior colliculus and the effects on saccadic eye movements made to visual or remembered targets were measured. An injection of muscimol selectively suppressed saccades to the movement field of the cells near the injection site. The affected area expanded over time, thus suggesting the diffusion of muscimol in the SC; the area never included the other hemifield, suggesting that the diffusion was limited to one SC. One of the monkeys became unable to make any saccades to the affected area. In contrast to muscimol, injection of bicuculline facilitated the initiation of saccades. GABA apparently has a powerful effect on the SC; potentiation or reduction of GABA inhibition alters the execution of saccadic eye movements. SC influences the velocity of saccadic eye movements in addition to their latency and accuracy.