AXONAL GUIDANCE OF DEVELOPING OPTIC NERVES IN FROG .2. ELECTROPHYSIOLOGICAL STUDIES OF PROJECTION FROM TRANSPLANTED EYE PRIMORDIA
AXONAL GUIDANCE OF DEVELOPING OPTIC NERVES IN FROG .2. ELECTROPHYSIOLOGICAL STUDIES OF PROJECTION FROM TRANSPLANTED EYE PRIMORDIA
复制标题
DOI：
10.1002/cne.901700104
复制
发表时间：
1976-01-01
影响因子：
2.5
通讯作者：
CAPRANICA, RR
中科院分区：
文献类型：
--
作者：
CONSTANTINEPATON, M;CAPRANICA, RR
当一只原始眼被移植到林蛙胚胎的耳位时，来自异位眼的视神经穿过髓质，并总是在同侧脊髓的背侧白质中建立一个束。为了响应对移植眼的视觉刺激，用金属微电极在变性后动物的脊髓内进行了细胞外记录。只有在移植的视神经成功穿透延髓的实验动物中才能记录到脊髓的视觉活动。这种活动常见于远低于移植视束背外侧位置的脊髓灰质。视觉活动的放电特征和适应特性往往与正常眼的视神经纤维相似，提示轴突或其侧支从移植的视束中分支出来，在脊髓内树枝状分布。然而，与正常视神经纤维不同的是，有时对移植眼的刺激会引起具有适应和/或反应特征的活动。实验动物脊髓中的视觉活动是通过在移植眼视野的限定区域内移动微小的黑色物体来驱动的。然而，没有证据表明移植的视网膜在这些异常穿透的脊髓中进行了系统的映射。
When a primordial eye was transplanted to the ear position in Rana pipiens embryos, the optic nerve from the ectopic eye penetrated the medulla and invariably established a tract in the dorsolateral white matter of the ipsilateral spinal cord. In response to visual stimulation of the transplanted eye, extracellular recordings with metal microelectrodes were conducted within the spinal cords of post-metamorphic animals. Visual activity in the spinal cord were only recorded in those experimental animals in which the transplanted optic nerve succeeded in penetrating the medulla. This activity was frequently encountered in the gray matter of the cord well below the dorsolateral position of the transplanted optic tract. The discharge characteristics and adaptation properties of the visual activity were often similar to that of optic nerve fibers from normal eyes suggesting that axons or their collaterals branch off from the transplanted optic tract and arborize within the spinal cord. However, occasionally stimulation of the transplanted eye evoked activity with adaptation and/or response characteristics unlike that of normal optic nerve fibers. Visual activity in the spinal cords of experimental animals were driven by moving small dark objects within circumscribed regions in the visual field of the transplanted eye. However no evidence of a systematic mapping of the transplanted retina within these abnormally penetrated spinal cords was found.