Latency of vestibular responses of pursuit neurons in the caudal frontal eye fields to whole body rotation
Latency of vestibular responses of pursuit neurons in the caudal frontal eye fields to whole body rotation
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DOI：
10.1007/s00221-006-0682-5
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发表时间：
2007-03-01
影响因子：
2
通讯作者：
Fukushima, Kikuro
中科院分区：
文献类型：
--
作者：
Akao, Teppei;Saito, Hiroshi;Fukushima, Kikuro
平滑追踪系统和前庭系统相互作用，通过将眼睛在空间的速度与头部和/或全身运动期间的目标速度相匹配，将视网膜目标图像保持在中心凹上。弓状沟底部额叶眼场的尾侧部分含有追踪相关神经元，大多数神经元对全身运动诱发的前庭刺激有反应。为了了解FEF追踪神经元在前庭和追踪信号相互作用中的作用，我们研究了不同前庭任务条件下头部稳定猴对水平全身旋转的放电调制的潜伏期和时程。选择具有水平优先方向的追踪神经元，并根据先前的标准将其分类为凝视速度神经元或眼睛/头部速度神经元(Fukushima等人)。见：《神经生理学杂志》83：563-587,2000)。在消除前庭-眼反射(VOR)、VORx1和无靶点的坐位台阶(VORD)过程中，观察这些神经元对20度/S的全身阶跃旋转的反应。接受测试的大多数追踪神经元(-70%)在Vord中反应潜伏期为80ms。这些初始反应在三种前庭任务条件下基本相似。最短潜伏期为20ms，模态值为24ms。这些反应在凝视速度神经元和眼/头速度神经元之间也是相似的，表明最初的反应(<；80ms)是由半规管输入引起的前庭反应。在VOR取消和X1期间，两组神经元的放电在椅子开始旋转后类似于90ms时出现分歧，与平稳追踪相关的潜伏期一致。平稳追踪时目标开始运动的最短潜伏期为80ms，模态值为95ms。通过平滑追踪相关的放电调制，预测两组神经元在VOR消除时和X1时的放电率差的时程。这些结果进一步支持了尾侧FEF参与前庭输入和追踪信号的整合。
The smooth pursuit system and the vestibular system interact to keep the retinal target image on the fovea by matching the eye velocity in space to target velocity during head and/or whole body movement. The caudal part of the frontal eye fields (FEF) in the fundus of the arcuate sulcus contains pursuit-related neurons and the majority of them respond to vestibular stimulation induced by whole body movement. To understand the role of FEF pursuit neurons in the interaction of vestibular and pursuit signals, we examined the latency and time course of discharge modulation to horizontal whole body rotation during different vestibular task conditions in head-stabilized monkeys. Pursuit neurons with horizontal preferred directions were selected, and they were classified either as gaze-velocity neurons or eye/head-velocity neurons based on the previous criteria (Fukushima et al. in: J Neurophysiol 83:563-587, 2000). Responses of these neurons to whole body step-rotation at 20 degrees/s were examined during cancellation of the vestibulo-ocular reflex (VOR), VOR x1, and during chair steps in complete darkness without a target (VORd). The majority of pursuit neurons tested (-70%) responded during VORd with latencies < 80 ms. These initial responses were basically similar in the three vestibular task conditions. The shortest latency was 20 ms and the modal value was 24 ms. These responses were also similar between gaze-velocity neurons and eye/head-velocity neurons, indicating that the initial responses (< 80 ms) were vestibular responses induced by semicircular canal inputs. During VOR cancellation and x1, discharge of the two groups of neurons diverged at similar to 90 ms following the onset of chair rotation, consistent with the latencies associated with smooth pursuit. The shortest latency to the onset of target motion during smooth pursuit was 80 ms and the modal value was 95 ms. The time course of discharge rate difference of the two groups of neurons between VOR cancellation and x1 was predicted by the discharge modulation associated with smooth pursuit. These results provide further support for the involvement of the caudal FEF in integration of vestibular inputs and pursuit signals.