Adolescence is associated with significant reductions in hippocampal cellular proliferation and neurogenesis, the physiological and behavioral implications of which are unclear. Though sex differences exist in these proliferative processes in adulthood, relatively little is known about the role sex plays in these adolescent-related changes. To address this gap, we examined cross-sectional area of the dentate gyrus and cellular proliferation, as measured by Ki-67 immunohistochemistry, in pre- (30 days), mid- (45 days), and post-adolescent (70 days) male and female rats. We also investigated the number of immature neurons using doublecortin (DCX) immunohistochemistry in pre- and post-adolescent males and females. Despite increases in the size of the dentate gyrus during adolescence, we found significant adolescent-related decreases in hippocampal proliferation in both males and females, with a more dramatic decrease in males, indicating both age- and sex-dependent changes in the dentate gyrus. We also found an adolescent-related decline in the number of immature neurons in the dentate gyrus of male rats and a female-biased sex difference in the number of immature neurons in adults. Given these significant changes in the dentate gyrus, these data suggest that this period in development might be particularly sensitive to internal and external factors known to modulate neurogenesis, with potential sex-specific neurobehavioral ramifications.

中文翻译：

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大鼠青春期海马细胞增殖和未成熟神经元数量的性别差异和相似性。

青春期与海马细胞增殖和神经发生的明显减少有关，尚不清楚其生理和行为含义。尽管在成年期的这些增生过程中存在性别差异，但对性别在这些与青少年相关的变化中所起的作用知之甚少。为了解决这一差距，我们在青春期前（30天），中期（45天）和青春期后（70天）检查了通过Ki-67免疫组织化学测量的齿状回的横截面积和细胞增殖。雄性和雌性大鼠。我们还调查了青春期前后男性和女性使用双皮质素（DCX）免疫组织化学的未成熟神经元的数量。尽管青春期齿状回的大小有所增加，我们发现男性和女性的海马增殖均与青春期相关，而男性的下降更为显着，这表明齿状回的年龄和性别相关变化。我们还发现，雄性大鼠齿状回中未成熟神经元的数量与青春期相关，成年后未成熟神经元的数量受女性偏见的性别差异。考虑到齿状回的这些显着变化，这些数据表明，发育的这一时期可能对已知的调节神经发生的内部和外部因素特别敏感，并具有潜在的性别特异性神经行为分支。我们还发现，雄性大鼠齿状回中未成熟神经元的数量与青春期相关，成年后未成熟神经元的数量受女性偏见的性别差异。考虑到齿状回的这些显着变化，这些数据表明，发育的这一时期可能对已知的调节神经发生的内部和外部因素特别敏感，并具有潜在的性别特异性神经行为分支。我们还发现，雄性大鼠齿状回中未成熟神经元的数量与青春期相关，成年后未成熟神经元的数量受女性偏见的性别差异。考虑到齿状回的这些显着变化，这些数据表明，发育的这一时期可能对已知的调节神经发生的内部和外部因素特别敏感，并具有潜在的性别特异性神经行为分支。