Chapman B
Center for Neuroscience, 1544 Newton Court, University of California, Davis, CA 95616 USA.
Science. 2000 Mar 31;287(5462):2479-82. doi: 10.1126/science.287.5462.2479.
In the adult mammal, retinal ganglion cell axon arbors are restricted to eye-specific layers in the lateral geniculate nucleus. Blocking neuronal activity early in development prevents this segregation from occurring. To test whether activity is also required to maintain eye-specific segregation, ganglion cell activity was blocked after segregation was established. This caused desegregation, so that both eyes' axons became concentrated in lamina A, normally occupied only by contralateral afferents. These results show that an activity-dependent process is necessary for maintaining eye-specific segregation and suggest that activity-independent cues may favor lamina A as the target for arborization of afferents from both eyes.
在成年哺乳动物中,视网膜神经节细胞轴突分支局限于外侧膝状核中特定眼的层。在发育早期阻断神经元活动可阻止这种分离的发生。为了测试维持特定眼分离是否也需要活动,在分离建立后阻断神经节细胞的活动。这导致了分离的消失,使得双眼的轴突都集中在A层,而该层通常仅由对侧传入纤维占据。这些结果表明,一个依赖活动的过程对于维持特定眼分离是必要的,并表明不依赖活动的线索可能使A层成为双眼传入纤维分支的目标。