Maheu Marissa E, Akbari Emis M, Fleming Alison S
Department of Psychology, University of Toronto at Mississauga, 3359 Mississauga Rd. N., Room 2037B-SE, Mississauga, Ontario, Canada L5L 1C6.
Brain Res. 2009 Apr 24;1267:18-24. doi: 10.1016/j.brainres.2009.02.029. Epub 2009 Feb 25.
Prolactin (PRL), an anterior pituitary hormone with neurogenic properties associated with pregnancy, has been implicated in oligodendrocyte proliferation during gestation, contributing to increased myelination in the maternal brain. However, PRL is elevated during lactation as well, suggesting that the postpartum (PP) period may contribute to additional gliogenesis in lactating females. In the present study, we assessed oligodendrocyte number in the corpus callosum (CC) of female Sprague-Dawley rats near the end of gestation, and at two weeks postpartum in both lactating and non-lactating dams, and in virgins. Though pregnant females did not differ significantly from any other group, lactating females had significantly more oligodendrocytes in the CC than virgins (p=.01), and in medial regions of the CC than non-lactating dams (p<.02). Oligodendrocyte number in the CC of pregnant and PP females correlated positively with the number of pups in their litter (r(2)=.68, p<.005). These results suggest that the gestational period contributes to oligodendrocyte proliferation or survival, likely mediated by an endocrine hormone whose concentration varies with the size of the litter. The PP period also contributes to increases in CC oligodendrocyte number, though it is unclear whether endocrine influences and/or pup-interaction underlie the differences in myelination between lactating and non-lactating groups. Further investigation is required in order to confirm whether the effects observed are mediated by members of the PRL-family, experience, and/or other gestational/PP endocrine hormones.
催乳素（PRL）是一种具有与妊娠相关的神经源性特性的垂体前叶激素，已被证实与妊娠期少突胶质细胞增殖有关，有助于增加母体大脑中的髓鞘形成。然而，PRL在哺乳期也会升高，这表明产后（PP）期可能有助于哺乳期雌性动物产生更多的神经胶质细胞。在本研究中，我们评估了雌性Sprague-Dawley大鼠在妊娠末期、产后两周的哺乳期和非哺乳期母鼠以及未生育母鼠胼胝体（CC）中的少突胶质细胞数量。虽然怀孕母鼠与其他任何组之间没有显著差异，但哺乳期母鼠CC中的少突胶质细胞比未生育母鼠显著更多（p = 0.01），并且在CC的内侧区域比非哺乳期母鼠更多（p < 0.02）。怀孕和产后母鼠CC中的少突胶质细胞数量与它们窝中的幼崽数量呈正相关（r(2)=0.68，p < 0.005）。这些结果表明，妊娠期有助于少突胶质细胞的增殖或存活，可能是由一种浓度随窝大小变化的内分泌激素介导的。产后时期也有助于增加CC中少突胶质细胞的数量，尽管尚不清楚内分泌影响和/或幼崽互动是否是哺乳期和非哺乳期组之间髓鞘形成差异的基础。需要进一步研究以确认观察到的效应是否由PRL家族成员、经验和/或其他妊娠/产后内分泌激素介导。
