Veraart C, De Volder A G, Wanet-Defalque M C, Bol A, Michel C, Goffinet A M
Positron Tomography Laboratory, University of Louvain, Belgium.
Brain Res. 1990 Feb 26;510(1):115-21. doi: 10.1016/0006-8993(90)90735-t.
Glucose utilization has been studied in the visual cortex of blind human subjects, by comparison with normal volunteers, using positron emission tomography. In 6 subjects who became blind early in life ('early blindness'), metabolism in visual cortex was elevated, comparable to that of normal subjects studied with the eyes open. By contrast, glucose utilization in visual areas of 6 human subjects who became blind after completion of visual development ('late blindness') was decreased, slightly lower than in normal volunteers studied with the eyes closed. This unexpected difference between early and late blind subjects might reflect the persistence, in early blindness, of supranumerary synapses which would escape the normal developmental decrease in synaptic density during infancy.
通过正电子发射断层扫描技术，与正常志愿者相比，对盲人受试者的视觉皮层中的葡萄糖利用情况进行了研究。在6名早年失明的受试者（“早期失明”）中，视觉皮层的代谢增强，与睁眼状态下的正常受试者相当。相比之下，6名在视觉发育完成后失明的受试者（“晚期失明”）的视觉区域中的葡萄糖利用减少，略低于闭眼状态下的正常志愿者。早期和晚期失明受试者之间这种意外的差异可能反映出，在早期失明中，存在多余的突触，这些突触在婴儿期会逃过突触密度正常的发育性降低。
