Fukushima Kikuro, Kasahara Satoshi, Akao Teppei, Kurkin Sergei, Fukushima Junko, Peterson Barry W
Department of Physiology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan.
Cereb Cortex. 2009 Feb;19(2):263-75. doi: 10.1093/cercor/bhn079. Epub 2008 May 14.
Eye and head movements are coordinated during head-free pursuit. To examine whether pursuit neurons in frontal eye fields (FEF) carry gaze-pursuit commands that drive both eye-pursuit and head-pursuit, monkeys whose heads were free to rotate about a vertical axis were trained to pursue a juice feeder with their head and a target with their eyes. Initially the feeder and target moved synchronously with the same visual angle. FEF neurons responding to this gaze-pursuit were tested for eye-pursuit of target motion while the feeder was stationary and for head-pursuit while the target was stationary. The majority of pursuit neurons exhibited modulation during head-pursuit, but their preferred directions during eye-pursuit and head-pursuit were different. Although peak modulation occurred during head movements, the onset of discharge usually was not aligned with the head movement onset. The minority of neurons whose discharge onset was so aligned discharged after the head movement onset. These results do not support the idea that the head-pursuit-related modulation reflects head-pursuit commands. Furthermore, modulation similar to that during head-pursuit was obtained by passive head rotation on stationary trunk. Our results suggest that FEF pursuit neurons issue gaze or eye movement commands during gaze-pursuit and that the head-pursuit-related modulation primarily reflects reafferent signals resulting from head movements.
在无头部限制的追踪过程中，眼睛和头部的运动是协调的。为了研究额叶眼区（FEF）中的追踪神经元是否携带驱动眼球追踪和头部追踪的注视追踪指令，训练头部可绕垂直轴自由旋转的猴子用头部追踪果汁供应器并用眼睛追踪目标。最初，供应器和目标以相同的视角同步移动。在供应器静止时测试对这种注视追踪有反应的FEF神经元对目标运动的眼球追踪情况，在目标静止时测试其对头部追踪的情况。大多数追踪神经元在头部追踪期间表现出调制，但它们在眼球追踪和头部追踪期间的偏好方向不同。虽然峰值调制发生在头部运动期间，但放电起始通常与头部运动起始不同步。少数放电起始同步的神经元在头部运动起始后放电。这些结果不支持头部追踪相关调制反映头部追踪指令的观点。此外，通过在静止躯干上被动旋转头部也能获得与头部追踪期间类似的调制。我们的结果表明，FEF追踪神经元在注视追踪期间发出注视或眼球运动指令，并且头部追踪相关调制主要反映头部运动产生的再传入信号。
