Yinon U, Chen M, Milgram A, Gelerstein S
Physiological Laboratory, Maurice and Gabriela Goldschleger Eye Research Institute Tel-Aviv University, Sackler Faculty of Medicine, Tel-Hasomer, Israel.
Brain Res Bull. 1991 Nov;27(5):553-71. doi: 10.1016/0361-9230(91)90028-i.
We have studied physiologically whether visual cortex cells in areas 17 and 18 of split-brain cats preserve their performance despite the blockage of both binocularity and of interhemispheric communication. The absolute majority of the cells in cats underwent split-brain surgery as kittens and adults and were driven by the ipsilateral eye, resulting in the absence of interhemispheric interaction. Similar results were found in cats and kittens that underwent only chiasm split surgery, although some recovery of callosal transfer was found in the latter. A remarkable loss of binocularity was found when only callosal transection was performed, both in adult cats and in kittens, although some ipsilateral eye dominance was observed in the latter. As to the deprived cats, while in the inexperienced hemisphere (ipsilateral to the deprived eye), the majority of the cells was visually unresponsive, in the contralateral (experienced) hemisphere, the majority was responsive. A considerable reduction in responsiveness was found in the callosally transected cats and kittens. Generally, a degradation of function was found in the various properties as a result of chiasmal and/or callosal transection. The main effect is the increased number of cells with diffuse and incomplete receptive fields. There was also a reduction in the proportion of orientation-selective cells, mainly in the split-brain cats. It was concluded that, despite the high amount of hemispheric independency in the normal brain, the integrity and simultaneous action of the two hemispheres are needed for the normal functioning of visual cortex cells.
我们从生理学角度研究了裂脑猫17区和18区的视皮层细胞，在双眼视觉和半球间联系均被阻断的情况下，是否仍能保持其功能表现。绝大多数接受裂脑手术的猫在幼年和成年时进行手术，且由同侧眼驱动，导致半球间无相互作用。在仅接受视交叉切开手术的猫和幼猫中也发现了类似结果，不过后者的胼胝体传递有一定程度的恢复。在成年猫和幼猫中，仅进行胼胝体横切时，均发现双眼视觉显著丧失，尽管在幼猫中观察到一些同侧眼优势。对于剥夺眼的猫，在未经历视觉刺激的半球（与剥夺眼同侧），大多数细胞对视无反应，而在对侧（经历过视觉刺激）半球，大多数细胞有反应。在胼胝体横切的猫和幼猫中，反应性有相当程度的降低。一般来说，由于视交叉和/或胼胝体横切，各种特性的功能都出现了退化。主要影响是具有弥散和不完整感受野的细胞数量增加。定向选择性细胞的比例也有所降低，主要是在裂脑猫中。研究得出结论，尽管正常大脑中半球独立性很高，但两个半球的完整性和协同作用对于视皮层细胞的正常功能是必需的。
