Winterson B J, Collewijn H
Brain Res. 1981 Sep 7;220(1):31-49. doi: 10.1016/0006-8993(81)90209-2.
Extracellular recordings were made of 46 well-isolated single units in the nucleus of the optic tract (NOT) from 27 rabbits which were paralyzed but unanesthetized. Rabbits were selected from 3 varieties with ocular albinism. These units showed short latencies (mean = 2.2 msec, S.D. = 0.4) to chiasmic stimulation suggestive of monosynaptic innervation from retinal ganglion cells. Receptive fields were large and receptive field centers were confined to the projection of the visual streak. All units showed direction selectivity in which preferred stimulus motions were always nearly horizontal in the anterior or posterior direction. The direction selectivity of the units was broad in that excitatory acceptance angles were 180 degrees. Single units recorded from NOT in albino rabbits could be classified into 4 types based on regions of direction selectivity. The most common (64%) type of unit had receptive fields with two regions of opposed direction selectivity. The preferred direction of motion was anterior in lateral and posterior visual fields and was posterior in anterior visual fields. Two smaller groups of units (13% and 11%) had receptive fields with only one preferred direction. When the receptive field was anterior, the preferred direction was posterior. When the receptive field was lateral or posterior, the preferred direction was anterior. The least commonly encountered type of unit (7%) had receptive fields with two regions of direction selectivity. Anterior visual fields gave rise to anterior direction selectivity and lateral and posterior visual fields gave rise to posterior direction selectivity. The characteristics of NOT units are similar to those described for NOT units in pigmented rabbits except for an inversion of direction selectivity to stimulation from anterior visual fields. NOT units in albino rabbits show posterior direction selectivity when stimulation arises from anterior visual fields. The difference in directional preference in the visual receptive fields of the units in the NOT of albino rabbit may be responsible for the inversion of optokinetic pursuit eye movements characteristic of albino rabbits.
在27只瘫痪但未麻醉的兔子的视束核（NOT）中，对46个分离良好的单个神经元进行了细胞外记录。这些兔子选自3个患有眼白化病的品种。这些神经元对交叉刺激的潜伏期较短（平均 = 2.2毫秒，标准差 = 0.4），提示来自视网膜神经节细胞的单突触支配。感受野较大，感受野中心局限于视觉条纹的投射区域。所有神经元都表现出方向选择性，其中偏好的刺激运动方向在前部或后部方向上总是接近水平。这些神经元的方向选择性较宽，兴奋接受角为180度。根据方向选择性区域，从白化病兔子的NOT中记录的单个神经元可分为4种类型。最常见（64%）的神经元类型的感受野有两个相反方向选择性的区域。运动的偏好方向在外侧和后部视野中是向前的，而在前部视野中是向后的。两组较小的神经元（13%和11%）的感受野只有一个偏好方向。当感受野在前部时，偏好方向是向后的。当感受野在外侧或后部时，偏好方向是向前的。最不常见的神经元类型（7%）的感受野有两个方向选择性区域。前部视野产生向前的方向选择性，外侧和后部视野产生向后的方向选择性。白化病兔子的NOT神经元的特征与有色兔子中描述的NOT神经元的特征相似，只是对来自前部视野的刺激的方向选择性发生了反转。当刺激来自前部视野时，白化病兔子的NOT神经元表现出向后的方向选择性。白化病兔子NOT中神经元视觉感受野方向偏好的差异可能是白化病兔子特征性的视动性追踪眼球运动反转的原因。
