Molotchnikoff S, Dubuc M
Can J Neurol Sci. 1977 Feb;4(1):31-7.
The responsiveness of visual cortex (VC) and superior colliculus (SC) was simultaneously compared following conditioning "ON" or "OFF" stimulation, in the rabbit. Average evoked responses were recorded simultaneously from the visual cortex ans superior colliculus. "ON" or "OFF" steps constituted the conditioning stimuli whereas the test stimulus consisted of optic nerve stimulation. All evoked responses exhibited a reversal of their polarity when the electrode was moved in the dorsoventral direction (Negative-Positive in the SC, Positive-Negative in the VC). This assured the somato-dentritic origin of the potentials. The results showed that responsiveness in both structures was significantly higher following an "OFF" simulus than after an "ON" step. Collicular responsiveness was higher than in the VC when the same conditioning stimulus was applied. The spatial distribution of the source of "OFF" responses was circumscribed to the ventral part of the superficial layer of the superior colliculus. These results suggest specific properties associated with the brightening and dimming systems.
在兔子身上，对视觉皮层（VC）和上丘（SC）在“开”或“关”条件刺激后的反应性进行了同时比较。从视觉皮层和上丘同时记录平均诱发反应。“开”或“关”阶跃构成条件刺激，而测试刺激由视神经刺激组成。当电极在背腹方向移动时，所有诱发反应的极性都会反转（上丘为负-正，视觉皮层为正-负）。这确保了电位的体树突起源。结果表明，在“关”刺激后，这两个结构的反应性均显著高于“开”阶跃后。当施加相同的条件刺激时，上丘的反应性高于视觉皮层。“关”反应源的空间分布局限于上丘表层的腹侧部分。这些结果表明了与亮暗系统相关的特定特性。
