Fischer W H, Schmidt M, Stuphorn V, Hoffmann K P
Allgemeine Zoologie & Neurobiologie, Ruhr-Universität, Bochum, Germany.
Exp Brain Res. 1996 Aug;110(3):435-45. doi: 10.1007/BF00229143.
Responses of relay cells in the A-laminae of the dorsal lateral geniculate nucleus (LGNd) during spontaneous saccades and saccade-like visual stimulation were extracellularly recorded in awake cats. Ninety-six out of 137 cells recorded (42 X and 54 Y cells) were responsive during spontaneous saccadic eye movements. All Y cells and 67% of the X cells responded with burst activity, i.e. with either one or two activity peaks during and after saccades. Thirty-three percent of the X cells were inhibited during saccades. Excitatory peaks occurred at mean latencies of 33 ms and 31 ms for X and Y cells, respectively. Comparable burst responses were obtained when retinal image shifts similar to those during saccades were induced by external saccade-like stimulus movements. However, the latencies of excitatory peak activity were significantly longer to external stimuli than to the onsets of saccades. This indicates the existence of an eye movement-related input which activates LGNd relay cells in addition to the visual input. We propose that the pretectogeniculate projection may contribute to the responses of LGNd relay cells following saccadic eye movements via a disinhibitory input and that this input could be involved in intra- and postsaccadic modulations of the transfer of visual signals to visual cortex.
在清醒的猫身上，通过细胞外记录的方式，研究了背外侧膝状核（LGNd）A层中继细胞在自发扫视和类扫视视觉刺激过程中的反应。在记录的137个细胞中，有96个（42个X细胞和54个Y细胞）在自发眼球扫视运动期间有反应。所有Y细胞和67%的X细胞以爆发性活动做出反应，即在扫视期间和之后有一个或两个活动峰值。33%的X细胞在扫视期间受到抑制。X细胞和Y细胞兴奋峰值出现的平均潜伏期分别为33毫秒和31毫秒。当通过外部类扫视刺激运动诱导出与扫视期间相似的视网膜图像移动时，可获得类似的爆发反应。然而，外部刺激引起兴奋峰值活动的潜伏期明显长于扫视开始时的潜伏期。这表明除了视觉输入外，还存在一种与眼球运动相关的输入，它能激活LGNd中继细胞。我们提出，顶盖前膝状投射可能通过去抑制性输入对扫视眼球运动后LGNd中继细胞的反应有贡献，并且这种输入可能参与了视觉信号向视觉皮层传递的扫视期间和扫视后的调制。
