The time of origin of neurons in the hippocampal region of the rhesus monkey

作者：PASKO T. RAKIC, Richard S. Nowakowski · 发表于：The Journal of Comparative Neurology · 年份：1981 · DOI：10.1002/cne.901960109 · 被引用次数：310 · 研究领域：Neurogenesis and neuroplasticity mechanisms、Axon Guidance and Neuronal Signaling、Neuroinflammation and Neurodegeneration Mechanisms

The time of origin of neurons in the hippocampal region was determined in a series of rhesus monkeys, each of which had been exposed to a pulse of tritiated thymidine (3H-TdR) at a different time during ontogeny and sacrificed between the second and fifth month after birth. No heavily labeled cells were found in the hippocampal region of animals exposed to 3H-TdR before embryonic day 33 (E33). Exposure to 3H-TdR given at E36 labels a few neurons in the deepest layers of the entorhinal area, and 3H-TdR given at E38 labels a small number of neurons in all hippocampal subdivisions. Although the first neurons are generated almost simultaneously throughout the hippocampal region, the proliferation ceases at a different time in each subdivision. The last neurons destined for the entorhinal area and presubiculum are generated between E70 and E75, whereas the last parasubicular neurons are generated between E75 and E80. The production of neurons that form the subiculum ends about two weeks earlier, between E56 and E65. Within the hippocampus, genesis of pyramidal cells ends between E70 and E80 in area CA1, between E56 and E65 in area CA2, between E65 and E80 in area CA1, between E56 and E65 in area CA2, between E65 and E70 in area CA3, and between E75 and E80 in area CA4. In contrast, the genesis of granule cells of the fascia dentata is considerably prolonged. It continues throughout the second half of gestation, declines steadily in the course of the first postnatal month, and tape...