Sestokas A K, Lehmkuhle S, Kratz K E
Department of Neurosurgery, University of Maryland School of Medicine, Baltimore 21201.
Vision Res. 1987;27(9):1399-408. doi: 10.1016/0042-6989(87)90150-7.
Visual response latencies and rise times of X and Y ganglion cells recorded in the optic tract of anaesthetized, paralyzed cats were measured during repeated stimulation with sinusoidal gratings. These measures were compared with visual latencies and rise times of X- and Y-cells in the dorsal lateral geniculate nucleus. Measurements were restricted to individual trials on which the instantaneous discharge rate exceeded a criterion amplitude defined in terms of the statistics of the baseline activity of each cell in order to screen out false alarm responses. The onset and peak latencies of ganglion Y-cells are about 10-15 msec shorter than those of ganglion X-cells at low spatial frequencies (less than 0.25 c/deg) but about 10-20 msec longer at higher spatial frequencies (greater than 0.75 c/deg/). The onset latencies of geniculate X- and Y-cells lag their ganglion counterparts by 10-20 msec. Despite a delay in onsets of geniculate responses, the peak latencies of geniculate and ganglion X-cells are similar, and peak latencies of geniculate Y-cells are even shorter than those of their ganglion inputs. The short latencies of the peak responses of geniculate Y-cells are related to their short response rise times. A functional consequence of the bursty, but fast responses of geniculate Y-cells may be to accelerate the processing of lower spatial frequencies by the retino-geniculate Y-cell pathway.
在对麻醉、麻痹的猫的视束中记录的X和Y神经节细胞进行正弦光栅重复刺激期间，测量其视觉反应潜伏期和上升时间。将这些测量结果与背外侧膝状核中X细胞和Y细胞的视觉潜伏期和上升时间进行比较。测量仅限于单个试验，在这些试验中，瞬时放电率超过根据每个细胞基线活动的统计数据定义的标准幅度，以筛选出误报反应。在低空间频率（小于0.25周/度）时，神经节Y细胞的起始潜伏期和峰值潜伏期比神经节X细胞短约10 - 15毫秒，但在高空间频率（大于0.75周/度）时则长约10 - 20毫秒。膝状核X细胞和Y细胞的起始潜伏期比它们对应的神经节细胞滞后10 - 20毫秒。尽管膝状核反应的起始存在延迟，但膝状核X细胞的峰值潜伏期与神经节X细胞相似，并且膝状核Y细胞的峰值潜伏期甚至比其神经节输入的峰值潜伏期更短。膝状核Y细胞峰值反应的短潜伏期与其短反应上升时间有关。膝状核Y细胞爆发性但快速反应的一个功能后果可能是通过视网膜 - 膝状核Y细胞通路加速对较低空间频率的处理。
