Suppression of visually and memory-guided saccades induced by electrical stimulation of the monkey frontal eye field. II. Suppression of bilateral saccades
Suppression of visually and memory-guided saccades induced by electrical stimulation of the monkey frontal eye field. II. Suppression of bilateral saccades
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DOI：
10.1152/jn.00085.2004
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发表时间：
2004-10-01
影响因子：
2.5
通讯作者：
Shinoda, Y
中科院分区：
文献类型：
--
作者：
Izawa, Y;Suzuki, H;Shinoda, Y
为了了解注视的神经机制，我们研究了额眼场（FEF）及其附近区域的电刺激对受过训练的猴子的视觉引导（Vsacs）和记忆引导眼跳（Msacs）的影响，发现电刺激引起两种类型的抑制：同侧眼跳的抑制和双侧眼跳的抑制。在本报告中，我们描述了双侧 Vsac 和 Msac 的抑制特性。双侧抑制位点的刺激在刺激期间以及刺激后大约 50 毫秒抑制了所有方向上 Vsac 和 Msac 的启动，但不影响这些眼跳的矢量。对于同向较大扫视和相对较小扫视，抑制更强，并且初始眼睛位置在扫视方向上移动更多的扫视。抑制同侧和对侧 Vsacs 的最有效刺激时间类似于眼跳开始前 40 - 50 ms，表明抑制最有可能发生在上丘和/或桥脑旁正中网状结构中。双侧眼跳的抑制位点位于面向下弓状沟的前弓回，刺激在小于或等于40 muA时会引起眼跳，但在80 muA时通常不会引起任何眼跳，这与同侧眼跳的情况不同，刺激在小于或等于50 muA时会引起眼跳。双侧抑制位点包含固定神经元。结果表明，FEF 双侧抑制区域的注视神经元可能通过抑制各个方向的眼跳来维持注视。
To understand the neural mechanism of fixation, we investigated effects of electrical stimulation of the frontal eye field (FEF) and its vicinity on visually guided (Vsacs) and memory-guided saccades (Msacs) in trained monkeys and found that there were two types of suppression induced by the electrical stimulation: suppression of ipsilateral saccades and suppression of bilateral saccades. In this report, we characterized the properties of the suppression of bilateral Vsacs and Msacs. Stimulation of the bilateral suppression sites suppressed the initiation of both Vsacs and Msacs in all directions during and similar to 50 ms after stimulation but did not affect the vector of these saccades. The suppression was stronger for ipsiversive larger saccades and contraversive smaller saccades, and saccades with initial eye positions shifted more in the saccadic direction. The most effective stimulation timing for the suppression of ipsilateral and contralateral Vsacs was similar to 40 - 50 ms before saccade onset, indicating that the suppression occurred most likely in the superior colliculus and/or the paramedian pontine reticular formation. Suppression sites of bilateral saccades were located in the prearcuate gyrus facing the inferior arcuate sulcus where stimulation induced suppression at less than or equal to 40 muA but usually did not evoke any saccades at 80 muA and were different from those of ipsilateral saccades where stimulation evoked saccades at less than or equal to50 muA. The bilateral suppression sites contained fixation neurons. The results suggest that fixation neurons in the bilateral suppression area of the FEF may play roles in maintaining fixation by suppressing saccades in all directions.