用脑光学成像术研究不同空间拓扑位置猫初级视皮层的空间频率反应特性

Spatial frequency tuning characteristics of cat primary visual cortex at different topological locations by optical imaging

采用基于内源信号的脑光学成像方法 ,在大范围视皮层研究了不同空间拓扑位置对应的皮层区的对光栅刺激空间频率反应特性。结果表明 ,周边视野对应区对高空间频率刺激反应极弱或没有反应 ,中心视野对应区对较宽的空间频率范围内的刺激均有反应 ,但对高频刺激反应更强 ;无论在周边对应区还是中心对应区 ,其视野越靠近中心 ,其空间频率调谐曲线和截止空间频率越靠近高频 ,而且这种过渡是平缓的。以上结果说明 ,猫初级视皮层空间频率反应除了具有柱状分布特点外 ,还随皮层对应的空间拓扑位置而变化 。

Using optical imaging based on intrinsic signals, we studied spatial frequency tuning characteristics of cat primary visual cortex at different visual topological locations. We found that the areas representing the peripheral visual field had null or very weak responses to high spatial frequency grating stimuli, whereas the areas representing the central visual field responded to the stimuli of a wide range of spatial frequencies with greater responses to high spatial frequencies. The more centered the corresponding visual field of the cortical area, the higher the cutoff spatial frequency. The spatial frequency tuning curves also tended to have a smooth shift along the cortical surface. The results above demonstrate that spatial frequency tuning characteristics of the primary visual cortex change according to different visual topological locations of the cortical areas, in addition to the existence of spatial frequency columns. It is suggested that the distribution of spatial frequency columns may be related to visual topology. [WT5HZ]