NEURAL ACTIVITY IN CORTICAL AREA MST OF ALERT MONKEY DURING OCULAR FOLLOWING RESPONSES
NEURAL ACTIVITY IN CORTICAL AREA MST OF ALERT MONKEY DURING OCULAR FOLLOWING RESPONSES
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DOI：
10.1152/jn.1994.71.6.2305
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发表时间：
1994-06-01
影响因子：
2.5
通讯作者：
YAMANE, S
中科院分区：
文献类型：
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作者：
KAWANO, K;SHIDARA, M;YAMANE, S
1. 我们研究了行为猴子的颞上沟（STS）神经元的反应特性，这些猴子在短暂、突然的大视场视觉刺激运动中放电，引起眼球跟随。大多数神经元对大视场视觉刺激的运动具有定向选择性，倾向于高刺激速度。神经元主要分布在内侧颞上区（MST）（187/250）和内侧颞中区（MT）（57/250）。进一步研究了MST神经元的反应特性。当一个大视场随机点模式以偏好的方向和偏好的速度移动每个神经元时，测量反应延迟。80%（120/150）的神经元在眼球运动前10毫秒被激活。通过系统改变刺激速度（10 ~ 160度/秒），研究了59个神经元反应潜伏期与眼动潜伏期的关系。随着刺激速度的增加，神经元和眼反应的潜伏期均降低。结果表明，随着刺激速度的变化，神经元反应潜伏期和眼反应潜伏期的时间差变化不大。通过插入一片磨砂玻璃来模糊随机的点图案，增加了神经元反应和眼球运动的延迟。当视觉刺激的时间频率超过20赫兹时，神经元和眼睛的反应都开始迅速下降。在40赫兹的频率下，神经元表现出一种独特的突然-暂停放电模式，眼球运动显示出振荡的迹象。MST神经元在眼跟随过程中的反应特性与之前报道的桥脑背外侧核（DLPN）神经元相似。我们的研究结果表明，MST神经元可能向DLPN神经元提供视觉信息，并可能在引起眼跟随中发挥作用。研究了55个MST神经元在眼球平滑追踪运动中的反应。这些神经元中的每一个都对移动的大视场视觉刺激做出反应，这引发了眼球跟随，其中40个神经元在黑暗中平滑追踪时被激活。在平滑追求和眼球跟随过程中，方向偏好不同的神经元反应潜伏期长，而在平滑追求和眼球跟随过程中，方向偏好相同的神经元反应潜伏期短。对于后者，平滑追逐时的反应潜伏期总是比眼球跟随时的反应潜伏期长。这些神经元可能在眼球跟随和平滑追踪过程中向同一类型的DLPN神经元提供视觉信息。我们观察了11个MST神经元的反应，当追逐目标被短暂关闭时，这些神经元在平滑追逐过程中有反应。在任何情况下，目标眨眼都会降低他们的反应和他们的平滑追踪速度。这在神经元反应中比在眼速度剖面中更早被发现。MST神经元放电频率的降低可能是由于目标的消失（视觉诱导），而不是来自眼速的反馈。
1. We studied response properties of neurons in the superior temporal sulcus (STS) of behaving monkeys that discharged during brief, sudden movements of a large-field visual stimulus, eliciting ocular following. Most neurons responded to movements of a large-field visual stimulus with directional selectivity, preferring high stimulus speeds. Neurons were mostly recorded in the medial superior temporal area (MST) (187/250) and the middle temporal area (MT) (57/250). Further response properties were studied in the MST neurons.2. Response latencies were measured when a large-field random dot pattern was moved in the preferred direction and preferred speed for each neuron. Eighty percent (120/150) of the neurons were activated 10 ms before the eye movements.3. The relationship between the latency of neuronal responses and that of eye movements was studied in 59 neurons by changing the stimulus speed systematically (10-160 degrees/s). The latencies of both neuronal and ocular responses decreased as stimulus speed increased. As a result, the time difference between the response latencies for neuronal and ocular responses varied little with changes in stimulus speed.4. Blurring of the random dot pattern, by interposing a sheet of ground glass, increased the latency of both neuronal responses and eye movements.5. With the use of a check pattern instead of random dots, both neuronal and ocular responses began to decrease rapidly when the temporal frequency of the visual stimulus exceeded 20 Hz. At 40 Hz the neurons showed a distinctive burst-and-pause firing pattern, and the eye movements showed signs of oscillation.6. The response properties of the MST neurons during ocular following were similar to those of the dorsolateral pontine nucleus (DLPN) neurons, reported previously. Our results indicate that the MST neurons may provide visual information to the DLPN neurons and may play a role in eliciting ocular following.7. Responses during smooth-pursuit eye movement were studied in 55 MST neurons. Each of these neurons responded to the moving large-field visual stimulus, which elicited ocular following, and 40 of these neurons were activated during smooth pursuit in the dark. Response latencies during smooth pursuit were long in those neurons having different directional preferences during smooth pursuit and ocular following but were short for those having the same directional preferences during smooth pursuit and ocular following. For the latter the response latency during smooth pursuit was always longer than that during ocular following. These neurons may provide visual information to the same type of DLPN neurons during both ocular following and smooth pursuit.8. We observed responses of 11 MST neurons, which responded during smooth pursuit, when the pursuit target was briefly turned off. In every case, target blinking reduced their responses and their smooth-pursuit eye velocity. This was seen much earlier in the neuronal responses than in the eye-velocity profile. The decrease in firing frequency of the MST neurons may be due to disappearance of the target (visually induced), rather than to feedback from eye velocity.