Sherman G F, Garbanati J A, Rosen G D, Yutzey D A, Denenberg V H
Brain Res. 1980 Jun 16;192(1):61-7. doi: 10.1016/0006-8993(80)91008-2.
Rats were handled daily for 3 min between birth and weaning, or were nonhandled controls. When adult, 4 males from each litter received a right neocortical ablation, a left ablation, a sham operation, or no surgery. A month later all animals were tested in the open field for 4 days, and their initial direction of movement from the starting square (whether right or left) was recorded. Non-handled rats with intact brains (sham-operated and no-surgery groups pooled) had a mean directionality score near zero, thus indicating no right-left spatial preference. However, non-handled animals without a left hemisphere were significantly more biased in going to the ipsilateral side than were their siblings with right-brain ablations. Thus, in non-handled animals behavioral symmetry in making spatial choices is due to balanced brain asymmetry, in which the right hemisphere biases the animal to move leftward while the left hemisphere acts to inhibit this response. In contrast, intact handled rats had a significant preference to go to the left, thus suggesting that in handled animals the right hemisphere controls spatial preference.
在出生至断奶期间，每天对大鼠进行3分钟的抚摸，或作为未接受抚摸的对照。成年后，从每窝中选取4只雄性大鼠，分别接受右侧新皮层切除、左侧切除、假手术或不进行手术。一个月后，所有动物在旷场中进行4天测试，并记录它们从起始方格开始移动的初始方向（向右或向左）。大脑完整的未接受抚摸的大鼠（假手术组和未手术组合并）的平均方向性得分接近零，这表明没有左右空间偏好。然而，没有左半球的未接受抚摸的动物比有右脑切除的同胞更倾向于向同侧移动。因此，在未接受抚摸的动物中，做出空间选择时的行为对称性是由于大脑不对称的平衡，其中右半球使动物向左移动，而左半球则抑制这种反应。相比之下，大脑完整且接受抚摸的大鼠明显偏好向左移动，这表明在接受抚摸的动物中，右半球控制空间偏好。
