Chang K, Van Sluyters R C, Olavarria J F
School of Optometry, University of California, Berkeley, USA.
Biol Res. 1995;28(3):219-26.
It has been previously reported that neonatal monocular enucleation in rats and hamsters induces the development of an anomalous band of callosal connections in the middle of area 17 (primary visual cortex) in the hemisphere ipsilateral to the remaining eye. In order to determine whether this effect is due to elimination of retinal activity in one eye, we used the anatomical tracer horseradish peroxidase (HRP) to study the pattern of visual callosal connections in rats in which retinal activity had been blocked by intraocular injections of tetrodotoxin during the first two weeks of life. We found that the callosal pattern in the hemisphere ipsilateral to the eye not treated with tetrodotoxin was not distinguishable from the pattern present in normal rats. In particular, we did not observe the anomalous extra band of callosal connections that occurs in area 17 in the hemisphere ipsilateral to the remaining eye in monocularly enucleated rats. These results indicate that blockade of retinal activity in one eye is not sufficient to cause the marked changes in the pattern of visual callosal connections that are induced by neonatal monocular enucleation.
先前已有报道称，新生大鼠和仓鼠单眼摘除眼球会导致在剩余眼睛同侧半球的17区（初级视觉皮层）中部出现胼胝体连接异常带。为了确定这种效应是否是由于一只眼睛的视网膜活动被消除所致，我们使用解剖示踪剂辣根过氧化物酶（HRP）来研究在出生后前两周通过眼内注射河豚毒素阻断视网膜活动的大鼠的视觉胼胝体连接模式。我们发现，未用河豚毒素处理的眼睛同侧半球的胼胝体模式与正常大鼠的模式没有区别。特别是，我们没有观察到在单眼摘除眼球的大鼠中，剩余眼睛同侧半球17区出现的胼胝体连接异常额外带。这些结果表明，一只眼睛的视网膜活动被阻断不足以引起新生单眼摘除眼球所诱导的视觉胼胝体连接模式的显著变化。
