胼胝体输入对猫皮层17/18交界区细胞方向和取向选择性的影响

THE INFLUENCE OF CALLOSAL AFFERENCE ONTO THE DIRECTIONAL AND ORIENTATIONAL SELECTIVITIES OF SINGLE NEURONS IN THE 17/18 BORDER REGION OF THE CAT

用抑制性神经递质GABA阻断胼胝体输入、用微机控制的运动光棒作为视觉刺激,用金属电极胞外记录技术,研究猫皮层17/18区交界附近细胞方向选择性和取向选择性的变化.在被检测的48个细胞中,50%细胞的方向选择性强度,54.2%细胞的取向选择性强度发生了改变;约20%细胞的最优反应方向或.及最优取向发生了10-30°的偏移;共有56.2%细胞的方向选择性、58.3%细胞的取向选择性受到明确的影响.这些结果表明胼胝体对皮层细胞视觉反应的贡献是多方面的.

In order to evaluate the influence of callosal afference onto the directional and or orientational selectivities. extracellular recordings with glass-coated tungsten electrodes were performed in the 17 18 border region of anesthetized cats, where transcallosal axons terminate most densely. and a smoothly moving bar on a CRT screen controlled by a mirco-computer was used as the visual stimulus. After blocking the callosal inputs by applying GABA on the surface of the opposite hemisphere (n = 48) . directional tuning strength was altered in 50% of the recorded cells, onentational tuning strength was altered in 54.2% of the cells. and perferred direction or and orientation shifted 10-30 in about 20% of the cells. In total, the directional selectivity in 56.2% of the cells and the orientational selectivity in 58.3% of the cells were altered in one way or both ways. The present studies suggest that the contributions of corpus callosum to the visual response of neurons in the opposite hemisphere are heteroaeneous.