Volchan E, Rocha-Miranda C E, Picanço-Diniz C W, Zinsmeisser B, Bernardes R F, Franca J G
Instituto de Biofisica CCF da UFRJ, Rio de Janeiro, Brazil.
Exp Brain Res. 1989;78(2):380-6. doi: 10.1007/BF00228910.
Single-units were recorded from the nucleus of the optic tract. Most of the units showed excitation in response to random check patterns presented on a tangent screen to the contralateral eye, moving in a temporal to nasal direction and/or inhibition in the opposite direction. The excitatory response to the temporal to nasal movement, observed in most units, was unchanged throughout the range of speeds tested, except for a decrease at the slowest (0.6 deg/s) and fastest (150 deg/s) speeds. On the other hand, the inhibitory responses evoked by a nasal to temporal movement, had a peak between 3 and 16 deg/s which decreased towards both extremes. An average of 45% of the units were influenced by the stimulation of the ipsilateral eye. In one third of them the response was very weak. In the remainder, the mean frequency of spikes in one direction of the horizontal movement was more than twice that in the opposite stimulus direction. In the great majority of these units, stimulation of each eye yielded the same overall pattern of directionality, that is, movement of the stimulus towards the recording side led to excitation and/or movement in the reverse direction led to inhibition. Inhibition was stronger than excitation in most ipsilaterally responding units. Excitatory responses elicited by the ipsilateral eye were always weaker than those by the contralateral but in a few cases the ipsilateral inhibitory component was more prominent than the contralateral one.
从视束核记录单个神经元活动。大多数神经元对投射到对侧眼切线屏上的随机方格图案产生兴奋反应，图案从颞侧移向鼻侧，和/或对相反方向的移动产生抑制反应。在大多数神经元中观察到的对从颞侧到鼻侧移动的兴奋反应，在测试的整个速度范围内保持不变，但在最慢（0.6度/秒）和最快（150度/秒）速度时有所下降。另一方面，由鼻侧到颞侧移动引起的抑制反应，在3至16度/秒之间有一个峰值，向两个极端方向下降。平均45%的神经元受到同侧眼刺激的影响。其中三分之一的反应非常微弱。在其余的神经元中，水平移动一个方向的平均放电频率比相反刺激方向的平均放电频率高出两倍多。在绝大多数这些神经元中，刺激每只眼睛产生相同的总体方向性模式，即，刺激向记录侧移动导致兴奋和/或向相反方向移动导致抑制。在大多数同侧反应的神经元中，抑制强于兴奋。同侧眼引起的兴奋反应总是弱于对侧眼，但在少数情况下，同侧抑制成分比侧抑制成分更突出。
