Huttenlocher P R
UCLA Forum Med Sci. 1975(18):123-40. doi: 10.1016/b978-0-12-139050-1.50013-6.
The hypothesis that specific defects in synaptic and dendritic development of cerebral cortex may form the anatomical basis in some cases of mental defect has been examined by electron microscopy and by use of the Golgi-Cos method. Two types of abnormality have been identified to date. One is a specific lesion of presynaptic terminals, first reported by Gonatas and Goldensohn (14) in a child with mental retardation and myoclonic seizures. This lesion, consisting of massive proliferation of membranous structures in terminal axons, appears to be rare and may be the anatomical substrate of one or more genetically determined dementing illnesses in infancy. More commonly, cerebral cortex from the severely retarded shows defects in number, length, and spatial arrangement of dendrites and synapses, best demonstrated by the Golgi method. Such abnormalities have been found in six out of eleven brains from severely retarded individuals examined by us. The etiology of the retardation was unknown in the majority; two had other recognizable developmental malformations of brain. It is suggested that a number of different etiological factors, if active during the period of rapid synaptic and dendritic growth in cerebral cortex (i. e., from the last trimester of pregnancy to the end of the first postnatal year) may result in stunted development of these structures.
大脑皮质突触和树突发育的特定缺陷可能在某些智力缺陷病例中构成解剖学基础这一假说，已通过电子显微镜检查以及使用高尔基-考克斯法进行了研究。迄今为止，已识别出两种异常类型。一种是突触前终末的特定病变，最早由戈纳塔斯和戈尔登索恩（14）在一名患有智力迟钝和肌阵挛性癫痫的儿童中报道。这种病变由终末轴突中膜性结构的大量增殖组成，似乎很罕见，可能是一种或多种婴儿期遗传性痴呆疾病的解剖学基础。更常见的是，严重智力迟钝者的大脑皮质在树突和突触的数量、长度及空间排列方面存在缺陷，这通过高尔基法能得到最佳证明。在我们检查的11例严重智力迟钝者的大脑中，有6例发现了此类异常。大多数病例中智力迟钝的病因不明；其中两例有其他可识别的脑部发育畸形。有人提出，许多不同的病因因素，如果在大脑皮质突触和树突快速生长的时期（即从妊娠晚期到出生后第一年年底）起作用，可能会导致这些结构发育迟缓。
