Minciacchi D, Antonini A
Behav Brain Res. 1984 Aug;13(2):183-92. doi: 10.1016/0166-4328(84)90148-7.
The importance of the corpus callosum for binocular interaction in areas 17 and 18 of the adult cat is still a matter of controversy, since its specific role in integrating information from the two eyes has been suggested by some and questioned by others. We have reanalyzed the problem by assessing binocular interaction for single neurons in areas 17 and 18 of adult cats submitted to section of the posterior two-thirds of the corpus callosum. In 5 cats this interhemispheric disconnection was performed from 10 days to 7 weeks before the electrophysiological recordings; in another cat callosal afferents to the recording sites were at first partially eliminated by an acute lesion of corresponding cortical zones in the other hemisphere, and thereafter completely interrupted by a posterior callosal section performed in the same recording session. Recordings were mainly aimed at the callosal zone of areas 17 and 18, which coincides with the border between these two areas and corresponds to visual field regions bordering the vertical meridian. Electrophysiological recordings were carried out in awake, unanesthetized animals in which all nociceptive pathways were previously interrupted by a midpontine pretrigeminal transection. The results indicate that the interhemispheric disconnection, whether acute or chronic, does not disrupt binocularity in areas 17 and 18; moreover, the analysis of the ocular dominance for binocular neurons did not reveal any imbalance between the inputs from the two eyes, since at all levels of eccentricity the majority of binocular neurons was equally activated by both eyes. Since in previous experiments on anesthetized cats, section of the corpus callosum apparently reduced binocular interaction in areas 17 and 18, we suggest that such an effect, which was lacking in our unanesthetized cats, was probably due to an interaction or summation between callosotomy and anesthesia.
胼胝体对成年猫17区和18区双眼相互作用的重要性仍是一个有争议的问题，因为一些人认为其在整合来自双眼的信息方面具有特定作用，而另一些人则对此表示质疑。我们通过评估成年猫17区和18区单神经元的双眼相互作用，重新分析了这个问题，这些成年猫的胼胝体后三分之二已被切断。在5只猫中，这种半球间的切断在电生理记录前10天至7周进行；在另一只猫中，首先通过对另一半球相应皮质区的急性损伤部分消除了记录部位的胼胝体传入纤维，然后在同一次记录过程中通过胼胝体后部切断将其完全中断。记录主要针对17区和18区的胼胝体区，该区域与这两个区域的边界重合，对应于与垂直子午线相邻的视野区域。电生理记录是在清醒、未麻醉的动物身上进行的，这些动物先前所有的伤害性通路都已通过脑桥中部三叉神经前横断而被中断。结果表明，无论是急性还是慢性的半球间切断，都不会破坏17区和18区的双眼性；此外，对双眼神经元的眼优势分析未发现双眼输入之间存在任何不平衡，因为在所有偏心率水平上，大多数双眼神经元被双眼同等程度地激活。由于在先前对麻醉猫的实验中，胼胝体切断明显降低了17区和18区的双眼相互作用，我们认为在我们未麻醉的猫中不存在这种效应，可能是由于胼胝体切断术与麻醉之间的相互作用或总和。
