Activity of fixation neurons in the monkey frontal eye field during smooth pursuit eye movements
Activity of fixation neurons in the monkey frontal eye field during smooth pursuit eye movements
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DOI：
10.1152/jn.00816.2013
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发表时间：
2014-07-01
影响因子：
2.5
通讯作者：
Suzuki, Hisao
中科院分区：
文献类型：
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作者：
Izawa, Yoshiko;Suzuki, Hisao
我们记录了在额叶眼野（FEF）的注视神经元的活动在训练的猴子和分析他们的活动在平稳的追求眼球运动。固定神经元密集地位于FEF的弓状回的尾侧部分面向下弓状沟，其中局灶性电刺激抑制了扫视的产生，并且以低于诱发电诱发扫视的阈值的强度在双侧方向上平滑地追求。而固定神经元在固定过程中的紧张性放电，他们表现出各种放电模式在顺利的追求，从减少活动的增加。其中，超过三分之二的人被发现在同侧和双侧方向的平稳追踪过程中活动减少。注视神经元的活动减少开始在追求启动，并继续在追求维持。当追赶眼跳在开始追求消除了一个步骤斜坡目标例程，减少活动的注视神经元仍然存在。在追求过程中的活动减少不依赖于没有目标的固定过程中的活动。基于这些结果，我们讨论了FEF在维持与其他各种脑区的固定的作用。我们认为，在FEF的固定神经元有助于抑制顺利的追求。这些结果表明，FEF固定神经元是一个更广义的视觉固定系统的一部分，通过该系统的抑制控制施加在平滑的追求，以及扫视。
We recorded the activity of fixation neurons in the frontal eye field (FEF) in trained monkeys and analyzed their activity during smooth pursuit eye movements. Fixation neurons were densely located in the area of the FEF in the caudal part of the arcuate gyrus facing the inferior arcuate sulcus where focal electrical stimulation suppressed the generation of saccades and smooth pursuit in bilateral directions at an intensity lower than the threshold for eliciting electrically evoked saccades. Whereas fixation neurons discharged tonically during fixation, they showed a variety of discharge patterns during smooth pursuit, ranging from a decrease in activity to an increase in activity. Of these, more than two-thirds were found to show a reduction in activity during smooth pursuit in the ipsilateral and bilateral directions. The reduction in activity of fixation neurons began at pursuit initiation and continued during pursuit maintenance. When catch-up saccades during the initiation of pursuit were eliminated by a step-ramp target routine, the reduced activity of fixation neurons remained. The reduction in activity during pursuit was not dependent on the activity during fixation without a target. Based on these results, we discuss the role of the FEF at maintaining fixation in relation to various other brain areas. We suggest that fixation neurons in the FEF contribute to the suppression of smooth pursuit. These results suggest that FEF fixation neurons are part of a more generalized visual fixation system through which suppressive control is exerted on smooth pursuit, as well as saccades.