Evidence for a change in the retino-hypothalamic projection in the rat following early removal of one eye
Evidence for a change in the retino-hypothalamic projection in the rat following early removal of one eye
复制标题
早期摘除一只眼睛后大鼠视网膜-下丘脑投射发生变化的证据
DOI：
10.1016/0006-8993(76)90652-1
复制
发表时间：
1976
期刊：
影响因子：
2.9
通讯作者：
W. Cowan
中科院分区：
文献类型：
--
作者：
B. Stanfield;W. Cowan
自从1958年Liu和Chambers关于脊髓部分去神经支配影响的研究发表以来，人们对神经元可塑性的问题产生了浓厚的兴趣。在过去的四五年里，关于这一主题的快速增长的文献已经被回顾了几次，我们只需要指出，尽管在神经系统的某些部分没有明显的可塑性，现在有证据表明基本上有三种不同类型的；脑和脊髓不同区域对部分去神经支配的反应：(i)去神经支配区域完整轴突的轴突发芽导致新突触的形成；的异常生长或方向错误。通常不终止于无神经区的纤维；(3)被切断的轴突的再生以及随后的无神经支配结构的再神经支配。由于各种原因，主要是技术上的原因，其中一些影响很难明确地证明。例如，许多关于可塑性的报道都是基于变性产物密度的变化，而没有充分考虑组织收缩和可能的跨神经元变化，这些变化在大量脱神经突后并不罕见。如果所讨论的传入神经通常局限于离散的细胞或纤维层（如海马区或外侧曲状体的背核），如果能够证明，在传入神经脱突之后，其他传入神经纤维进入被剥夺区4,7，则大多数困难都可以消除。在本研究中，我们报告了下丘脑视交叉上核的神经支配在早期切除一只眼睛后产生的部分去神经支配的变化。自从证明视交叉上核接受来自视网膜的直接输入以来，人们一直把注意力集中在视交叉上核上，并且这种输入可能是许多减少光线的行为和神经内分泌现象的原因。视网膜-下丘脑投影之所以对我们的目的特别感兴趣，是因为迄今为止所研究的每一种哺乳动物的投影都是双侧的，并且始终比对侧的视交叉上核重
Since the publication in 1958 of Liu and Chambers' study of the effects of partial denervation of the spinal cord 6, a good deal of interest has been generated in the problem of neuronal plasticity. As the rapidly growing literature bearing on this subject has been reviewed several times in the past 4 or 5 years, we need only point out that, although in some parts of the nervous system there is no demonstrable plasticity, there is now evidence for essentially three different types of; esponse to partial denervation in different regions of the brain and spinal cord:(i) axonalsprouting leading to the formation of new synapses by intact axons in the denervated region;(ii) aberrant growth or the misrouting of. fibers which do not normally terminate in the denervated region; and (iii) regeneration of axons which have been severed and the subsequent reinnervation of a denervated structure. For various reasons, mostly technical, some of these effects have been difficult to demonstrate unequivocally. For example, many of the reports of plasticity have been based on changes in the density of degeneration products without adequately taking into consideration tissue shrinkage and possible transneuronal changes which not infrequently occur following massive deafferentation. Where the afferents in question are normally confined to discrete cellular or fibrous laminae (as in the hippocampal region or the dorsal nucleus of the lateral geniculate body), most of these difficulties are obviated if it can be shown that, following deafferentation, other afferent fibers move into the deprived zone 4, 7. In the present study we report changes in the innervation of the suprachiasmatic nucleus of the hypothalamus following partial denervation produced by the early removal of one eye. Attention has been focused on the suprachiasmatic nucleus since the demonstration that it receives a direct input from the retina 3, 9 and that this input is probably responsible for many light-reduced behavioral and neuroendocrine phenomenaaL What makes the retino-hypothalamic projection of particular interest for our purpose is the observation that in every mammal studied so far the projection is bilateral, and consistently heavier to the suprachiasmatic nucleus of the contra-