Goldman P S, Galkin T W
Brain Res. 1978 Sep 8;152(3):451-85. doi: 10.1016/0006-8993(78)91103-4.
Anatomical and behavioral consequences were examined following bilateral or unilateral resections of the presumptive dorsolateral prefrontal cortex in 4 rhesus monkey fetuses at E102 (102nd embryonic day), E104, E106 and E119, with subsequent replacement in utero and delivery at later stages of development. Unoperated monkeys of appropriate pre- and postnatal ages served as controls for certain features of morphogenesis and tectogenesis. Monkeys given comparable unilateral or bilateral lesions at selected postnatal ages were used as controls for the behavioral effects of prenatal resection as well as for neuropathological examination. The behavioral evaluation provided evidence for extraordinary preservation of function after frontal cortical resection in the prenatal period. During the entire course of its postnatal development, a monkey that sustained bilateral resection as a fetus at E106 performed surprisingly well and clearly with the competence of unoperated monkeys of identical or older ages on tasks selective for dorsolateral prefrontal cortical function; it did not exhibit deficits characteristic of animals that have comparable or even smaller resections as juveniles or adults. Following either unilateral or bilateral resection prior to E106, ectopic sulci and gyri appeared in intact regions of the frontal lobe of each hemisphere, as well as in locations at a considerable distance from the lesions, such as the temporal and occipital lobes. The cytoarchitectonic characteristics of the cortex in these anomalous gyri were typical of adjacent cortex in the regions in which they appeared. Examination of the parvocellular subdivision of the mediodorsal thalamic nucleus yielded the novel finding that this principal source of essential projections to the dorsolateral prefrontal cortex contained a virtually normal number of neurons in postnatal monkeys, following unilateral or bilateral lesions performed at or before E106, and exhibited only a partial loss of neurons after surgery at E119. The same cells regularly degenerate following comparable resections in the postnatal period. The survival of these neurons in prenatally operated monkeys is unprecedented, and can be explained by several hypotheses, including the possibility that their axons become rerouted to their structures in the absence of their normal targets. The present results thus demonstrate that ablation of a circumscript area of the frontal cortex in a non-human primate a full two months before birth may leave the functions later to be subserved by that area unaffected. Such early surgical intervention results in significant alteration in the gross morphological characteristics of the cortex, and apparently induces a functionally compensatory reorganization of thalamocortical connections. Similar principles may account for sparing of function following early damage to the human brain.
对4只恒河猴胎儿（胚胎第102天、第104天、第106天和第119天）双侧或单侧切除推测的背外侧前额叶皮质后，观察其解剖学和行为学后果，随后将其子宫内复位并在发育后期分娩。适当产前和产后年龄的未手术猴子作为形态发生和构造发生某些特征的对照。在选定的产后年龄给予类似单侧或双侧损伤的猴子作为产前切除行为效应以及神经病理学检查的对照。行为评估提供了证据，表明产前额叶皮质切除后功能得到了非凡的保留。在其产后发育的整个过程中，一只在胚胎第106天作为胎儿时接受双侧切除的猴子表现出奇地好，在对背外侧前额叶皮质功能有选择性的任务上，明显具有与同龄或年龄更大的未手术猴子相当的能力；它没有表现出幼年或成年时进行了类似甚至更小切除的动物所特有的缺陷。在胚胎第106天之前进行单侧或双侧切除后，每个半球额叶完整区域以及与病变有相当距离的部位，如颞叶和枕叶，出现了异位沟回。这些异常脑回中皮质的细胞构筑特征与它们出现区域的相邻皮质典型特征相同。对丘脑背内侧核小细胞亚群的检查有了新发现，即这个向背外侧前额叶皮质发出重要投射的主要来源，在胚胎第106天或之前进行单侧或双侧损伤后，出生后的猴子中神经元数量基本正常，而在胚胎第119天手术后仅表现出部分神经元丢失。在产后进行类似切除后，相同的细胞通常会退化。这些神经元在产前手术的猴子中存活是前所未有的，可以用几种假说来解释，包括在没有正常靶标的情况下它们的轴突重新定向到其结构的可能性。因此，目前的结果表明，在出生前整整两个月对非人类灵长类动物额叶皮质的一个限定区域进行切除，可能不会影响该区域后来要承担的功能。这种早期手术干预导致皮质大体形态特征发生显著改变，并且显然诱导了丘脑皮质连接的功能代偿性重组。类似的原理可能解释了人类大脑早期损伤后功能的保留。
