CHEMOAFFINITY IN ORDERLY GROWTH OF NERVE FIBER PATTERNS AND CONNECTIONS
CHEMOAFFINITY IN ORDERLY GROWTH OF NERVE FIBER PATTERNS AND CONNECTIONS
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DOI：
10.1073/pnas.50.4.703
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发表时间：
1963-01-01
影响因子：
11.1
通讯作者：
SPERRY, RW
中科院分区：
文献类型：
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作者：
SPERRY, RW
1963年7月29日在对神经纤维生长和终止的早期观察中发现，不同类型的纤维必须通过选择性的化学或电力引导到它们各自的末端器官和其他连接部位。像趋化性、趋化性、趋化性和神经趋向性这样的解释术语在本世纪初被Cajal7和其他人普遍使用。这些选择性的概念后来受到了攻击，特别是在1930年的S和40年的S期间，当时更多的分析性实验方法应用于神经生长的力学，似乎排除了化学或电气选择性的存在，而倾向于以机械为主的解释。347我们相信，前面描述的许多明显选择性的例子，以及中枢神经系统和纤维系统的总体发育模式，在力学基础上得到了更恰当和正确的解释，特别是在机械应力对组织超微结构的定向效应以及由此在生长介质的胶体基质中形成亚微观机械导引线系统方面。在这场反选择性运动的巅峰时期，我从间接和部分行为的证据中被引导，在1939年再次假设神经生长中的一种化学选择性形式，在某些方面甚至比先前的提议更极端。该假说简写为18-24，提出神经中枢中突触连接的模式，包括迄今为止主要归因于各种形式的功能塑造的网络组织的精细细节，必须由生长机制直接处理，与功能无关，并且从一开始就具有非常严格的突触形成的选择性。突触联系的建立和维持被认为是由高度特定的细胞化学亲和力调控的，这种细胞化学亲和力通过自我分化、末端接触诱导和胚胎梯度效应在不同类型的神经元中系统地出现。在大多数科学领域，本能仍然是一个不光彩的术语，当神经生长的概念被机械理论强烈主导时，这一点一开始似乎不太可能，而且几乎不比当时一些相反的解释更疯狂，比如2‘33年提出要取代它。然而，当通过实验测试时，从20世纪40年代18-24年代开始的一项又一项研究得出了非常符合的结果。简而言之，每当中央纤维系统被切断并移植或只是被粗糙的手术切面搅乱时，再生总是导致有序的功能恢复，并在排除再教育调整的条件下。功能结果总是像是乱七八糟的纤维在再生过程中不知何故自我解体，并设法“回到”它们最初和正确的中枢神经末梢上。从这些结果看来，似乎有必要得出结论，即大脑和脊髓的细胞和纤维可能带有某种单独的识别标签
Communicated July 29, 1963 In early observations on the outgrowth and termination of nerve fibers, it ap-peared that different fiber types must be guided to their respective end organs and other connection sites by selective chemical or electrical forces. Explanatory terms like chemotaxis, chemotropism, galvanotaxis, and neurotropism were commonly employed by Cajal7 and others early in the century. These selectivity concepts later came under attack, especially during the 1930's and 40's when the application of more analytic experimental approaches to the mechanics of nerve growth seemed to rule out the presence of either chemical or electrical selectivity in favor of a predominantly mechanical interpretation. 347 The numerous examples of apparent selectivity described earlier, as well as the developmental patterning of the central nervetracts and fiber systems in general, we came to believe, were more properly and correctly explained on a mechanical basis, particularly in terms of the orienting effects of mechanical stresses on tissue ultrastructures and the resultant formation of submicroscopic systems of mechanical guide lines in the colloidal matrix of the growing medium. At the height of this antiselectivity movement I was led, from evidence indirect and partly behavioral, to postulate again in 1939 a form of chemical selectivity in nerve growth even more extreme in some respects than in the earlier proposals. The hypothesis, 18-24 in brief, suggested that the patterning of synaptic connections in the nerve centers, including those refined details of network organization heretofore ascribed mainly to functional molding in various forms, must be handled instead by the growth mechanismdirectly, independently of function, and withvery strict selectivity governing synaptic formation from the beginning. The establishment and maintenance of synaptic associations were conceived to be regulated by highly specific cytochemical affinities that arise systematically among the different types of neurons involved via self-differentiation, induction through terminal contacts, and embryonic gradient effects.Coming at a time when" instinctive" was still a disreputable term in most scientific quarters, and when concepts of nerve growth were strongly dominated by the mechanical theory, this seemed a long shot at first and hardly less wild than some of the opposing interpretations of the day like the" resonance principle" 2'33 that it was proposed to replace. When tested experimentally, however, study after study through the 1940's18-24, 29 yielded results that fit nicely. In brief, whenever central fiber systems were disconnected and transplanted or just scrambled by rough surgical section, regrowth always led to orderly functional recovery and under conditions that precluded re-educative adjustments. The functional outcome was always as ifthe scrambled fibers somehow unsorted themselves in regeneration and managed to" home in" on their original and proper central nerve terminals. It seemed a necessary conclusion from these results that the cells and fibers of the brain and cord must carry some kind of individual identification tags, presumably