同时性传入刺激引起大鼠体感皮层的功能重组

Functional Reorganization of Rat Somatosensory Cortex Induced by Synchronous Afferent Stimulation

将大鼠的一对面部须毛粘合以便提供对须毛的同时刺激,4～8d后利用微电极在初级体感皮层测定各须毛的代表区,发现粘合须毛与正常对照大鼠须毛及自身的未粘合须毛相比,其皮层代表区有了显著的改变,主要是该对须毛代表区会聚面积的扩大。这一发现支持过去的假设;皮层代表区及感受野的形成是由输入的相对强度及输入的时间结构决定的。

Detailed microelectrode maps of the S1 vibrissal zone were derived in a series of normal adult rats in which the tips of a pair of adjacent vibrissae had been glued together for 4-8 days to 'promote their simultaneous stimulation. The results showed that there was a significant (on average, 5-to 6-fold)enlargement of the conjoint functional cortical representation of temporarily fused whiskers. when compared with matched normative data. The histological reconstruction of barrel fields in experimental cases revealed that these enlarged cortical repre- sentations of fused whiskers occupied cortical zones equivalent to the areas of several barrels. The present experiments support the hypothesis that cortical representation and receptive fields are shaped by the relative magnitudes and time structures of afferent inputs.