MYELINATION OF CORTICAL-HIPPOCAMPAL RELAYS DURING LATE ADOLESCENCE
MYELINATION OF CORTICAL-HIPPOCAMPAL RELAYS DURING LATE ADOLESCENCE
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DOI：
10.1093/schbul/15.4.585
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发表时间：
1989-01-01
影响因子：
6.6
通讯作者：
BENES, FM
中科院分区：
文献类型：
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作者：
BENES, FM
雅科夫列夫收藏中的正常发育系列大脑已被检查，以探索与精神分裂症有关的各种大脑区域在青春期后期可能显示髓鞘形成变化的可能性，这一时期与这种疾病的早期症状的出现相吻合。前额叶，扣带，海马旁（内嗅）皮质，以及穿通通路，扣带束，海马，进行了仔细检查，因为这些地区最近被发现在精神分裂症中表现出各种神经病理学差异。对这些标本的观察证实了Yakovlev和Lecours（1967）的早期报告，即初级运动和感觉皮质在生命的第一个十年早期就显示出强大的髓鞘形成。相比之下，联合皮质区显示髓磷脂染色量增加，只有到第二个十年，虽然一些皮质区，如扣带和基底额叶皮质，仍然在整个生命中髓鞘化差。然而，最引人注目的发现是在青春期后期，下托和下托前区域的髓鞘形成增加。下托髓鞘形成的增加被定位于表面的一个离散区域，在该区域，穿通通路的纤维在向齿状区行进时聚集。在相邻的下托前区也显示髓鞘染色增加的类似区域可能包含扣带束的远端部分。支持后一种可能性是从一个单一的情况下，立体定位放置的病变引起中断扣带回束显示较少的髓鞘在前的有效病变侧的区域。这些以前未报道的研究结果进行了讨论，在正常的大脑电路介导的动机，注意力和情感行为。有人建议，髓鞘化的关键环节，在这个电路可能是“允许”的表达以前潜在的缺陷，在精神分裂症的大脑。
The normal developmental series brains in the Yakovlev Collection has been examined to explore the possibility that various brain regions implicated in schizophrenia may show changes in myelination during late adolescence, a period coinciding with the appearance of early symptoms of this disorder. The prefrontal, cingulate, and parahippocampal (entorhinal) cortex, as well as the perforant pathway, cingulum bundle, and hippocampus, were closely examined because these regions have recently been found to show various neuropathological differences in schizophrenia. Observation of these specimens has confirmed earlier reports by Yakovlev and Lecours (1967) that primary motor and sensory cortices show robust myelination early in the first decade of life. In contrast, associative cortical areas show increased amounts of myelin staining only by the second decade, although some cortical areas, like the cingulate and basofrontal cortex, remain poorly myelinated throughout life. The most striking finding, however, was the appearance of increased myelination of the subicular and presubicular regions during late adolescent period. Increased myelination in the subiculum was localized to a discrete region at the surface where fibers of the perforant pathway are known to aggregate as they course toward the area dentata. The comparable region in the adjacent presubicular area that also showed increased myelin staining probably contains distal portions the cingulum bundle. Support for this latter possibility was obtained from a single case in which a stereotaxically placed lesion causing interruption of the cingulum bundle showed less myelin in the presubicular area of the effectively lesioned side. These previously unreported findings are discussed in relation to normal brain circuitry mediating motivational, attentional, and affective behavior. It is suggested that myelination of key linkages in this circuitry may be “permissive” for the expression of a previously latent defect in schizophrenic brain.