動的または静的単一方位の継続的視体験によって誘導される方位マップの再組織化

抄録

To examine the plastic changes in orientation selectivity of developing visual cortex, we manipulated visual experience of kittens for 1-7 weeks under a freely moving condition, mounting cylindrical-lens-fitted goggles to present uni-axially elongated images of their environments, or spherical-lens-fitted goggles to present a stationary black-and-white oriented grating. We performed intrinsic signal optical imaging from those animals to reconstruct cortical representation of orientation preferences. For exposure to either a dynamic or stationary single orientation through the goggles, the extreme over-representation of exposed orientation was found in the visual cortex immediately after 1-2 weeks of continuous goggle rearing. For kittens exposed to a dynamic single orientation for a longer time, reorganized orientation maps were preserved although the degree of over-representation was somehow reduced. However, for kittens persistently exposed to a stationary oriented grating for long time, the over-representation effect almost disappeared or in some cases the orientation maps paradoxically exhibited the over-representation of the orientation orthogonal to the exposed orientation. It is suggested that the consolidation of reorganized orientation maps requires the experience of moving visual stimuli with behavioral relevance. [J Physiol Sci. 2006;56 Suppl:S60]