Márkus Zita, Berényi Antal, Paróczy Zsuzsanna, Wypych Marek, Waleszczyk Wioletta J, Benedek György, Nagy Attila
Department of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10, H-6720 Szeged, Hungary.
Neurosci Lett. 2009 Apr 17;454(1):76-80. doi: 10.1016/j.neulet.2009.02.063. Epub 2009 Mar 3.
Although the visual perception depends on the integration of spatial and temporal information, no knowledge is available concerning the responsiveness of neurons in the intermediate layers of the superior colliculus (SCi) to extended visual grating stimuli. Accordingly, we set out to investigate the responsiveness of these neurons in halothane-anesthetized cats to drifting sinewave gratings at various spatial and temporal frequencies. The SCi units responded optimally to gratings of low spatial frequencies (none of the analyzed SCi units exhibited maximal activity to spatial frequencies higher than 0.3c/deg) and exhibited low spatial resolution and narrow spatial frequency tuning. On the other hand, the SCi neurons preferred high temporal frequencies and exhibited high temporal resolution. Thus, the SCi neurons seem to be good spatio-temporal filters of visual information in the low spatial and high temporal frequency domain. Based upon the above summarized results we suggest that the SCi units can detect large contours moving at high velocities well, but are unable to distinguish small details. This is in line with the generally held view that the SCi could possess visuomotor function, such as organizing the complex, sensory-guided oculomotor and skeletomotor responses during the self-motion of the animal.
尽管视觉感知依赖于空间和时间信息的整合,但关于上丘中间层(SCi)神经元对扩展视觉光栅刺激的反应性,目前尚无相关研究。因此,我们着手研究在氟烷麻醉的猫中,这些神经元对不同空间和时间频率的漂移正弦波光栅的反应性。SCi神经元对低空间频率的光栅反应最佳(所分析的SCi神经元中,没有一个对高于0.3c/deg的空间频率表现出最大活性),并且表现出低空间分辨率和窄空间频率调谐。另一方面,SCi神经元偏好高时间频率并表现出高时间分辨率。因此,SCi神经元似乎是低空间和高时间频率域中视觉信息的良好时空滤波器。基于上述总结结果,我们认为SCi神经元能够很好地检测高速移动的大轮廓,但无法区分小细节。这与普遍认为的SCi可能具有视觉运动功能的观点一致,例如在动物自我运动期间组织复杂的、由感觉引导的眼球运动和骨骼运动反应。