Stimulation of the superior colliculus in the alert cat
Stimulation of the superior colliculus in the alert cat
复制标题
刺激警觉猫的上丘
作者：
D. Guitton;M. Crommelinck;A. Roucoux
猫上级丘（SC）的电刺激，结合引起的眼球运动和组织学验证的电极位置的精确测量，揭示了丘组织的显著前后变化。三个区域可以定义在SC的基础上的眼动模式和相关的颈肌肌电活动诱发的更深的层。前区与浅层中包含的视觉视网膜定位编码图的中心25 °同延。从这个区域诱发的眼跳也被视网膜定位编码，并且EMG活动的潜伏期取决于眼睛在眼眶中的位置。类似的观察适用于整个猴SC。中间区与25 °-70 °的视觉投射同延。从这个区域诱发的扫视是“目标导向的”，并与不变的，短潜伏期的EMG反应。后区位于SC的尾外侧部，从该区诱发的眼球运动是与恒定潜伏期EMG活动相关的中心扫视。目前的结果与先前证明的前后变化的预测SC，表明运动策略控制的目光转向视觉目标的变化取决于目标在视野中的位置。
SummaryElectrical stimulation of the cat superior colliculus (SC), in conjunction with the accurate measurement of elicited eye movements and histologically verified electrode positions, has revealed a striking antero-posterior variation in collicular organization. Three zones could be defined in the SC on the basis of eye movement patterns and associated neck muscle EMG activity evoked from the deeper layers. The Anterior zone was coextensive with the central 25 ° of the visual retinotopically coded map contained in the superficial layers. Saccades evoked from this zone were also retinotopically coded, and the latency of EMG activity depended on the position of the eye in the orbit. A similar observation applies to the entire monkey SC. The Intermediate zone was coextensive with the 25 °–70 ° of visual projections. Saccades evoked from this region were “goal-directed” and were associated with invariant, short latency EMG responses. The Posterior zone was found in the extreme caudo-lateral portion of the SC. Eye movements evoked from this zone were centering saccades associated with constant latency EMG activity. The present results in conjunction with previously demonstrated antero-posterior variations in projections to the SC, suggest that the motor strategies controlling gaze shifts toward visual targets vary depending on the location of the target in the visual field.