Variation in Maternal Care Influences Ventromedial Hypothalamus Activation in the Rat
Variation in Maternal Care Influences Ventromedial Hypothalamus Activation in the Rat
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DOI：
10.1111/j.1365-2826.2011.02124.x
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发表时间：
2011-05-01
影响因子：
3.2
通讯作者：
Meaney, M. J.
中科院分区：
文献类型：
--
作者：
Cameron, N. M.;Soehngen, E.;Meaney, M. J.
大鼠在母体护理方面的自然差异是女性神经内分泌系统和性行为个体差异的重要来源。因此，与低舔和梳理(LG)母亲的雌性后代相比，低舔和梳理(LG)母亲抚养的雌性更容易接受男性，表现出更高的前凸评级，并且更有动力交配。在本研究中，我们研究了母体护理的自然变化对下丘脑腹内侧核(VMHvl)细胞群的影响以及对雌性大鼠生殖成功的影响。应用雌激素受体(PER)和孕激素受体(PR)磷酸化的免疫组织化学方法，研究发情前期和发情间期高LG和低LG母鼠雌性后代的VMHvl。第二个实验调查了性行为和交配对发情前期和卵巢切除高的雌性后代VMHvl中c-Fos表达的影响，以及雌性后代的情况。最后，我们考察了母体效应对孕期状态建立的影响。低LG母鼠发情前期雌性后代中VMHvl Perα免疫反应阳性细胞数较多，发情前期PR含量最高，而间情期PR含量最高。有趣的是，在发情前期组中，在交配后，接受性较差的高密度雌性在VMH中表现出更高的c-Fos表达。当两组切除卵巢并接受激素替代后，交配后c-Fos表达的差异消失。最后，与高LG雌性相比，低LG雌性后代在5分钟间隔内只接受7次插管时，假孕的几率更高。较低的母体护理水平可能有利于低LG后代的繁殖成功，因为它增加了Perα和雌激素依赖的前凸行为，并降低了交配后的c-Fos，从而抑制了发情终止。
Natural variation in maternal care in the rat is an important source of individual differences in the female neuroendocrine system and sexual behaviours. Thus, females reared by low licking and grooming (LG) mothers are sexually more receptive to males, showing higher lordosis ratings, and are more motivated to mate compared to female offspring of high LG mothers. In the present study, we investigated the effect of natural variations in maternal care on the ventrolateral part of the ventromedial hypothalamus (VMHvl) cell population and on the reproductive success of the female rat. Immunohistochemistry for phosphorylated oestrogen-receptor (pER) alpha and progesterone receptor (PR) were used to study the VMHvl of female offspring of high and low LG mothers at pro-oestrus and dioestrus. A second experiment investigated sexual behaviour and the effect of mating on c-Fos expression in the VMHvl of pro-oestrus and ovariectomised high and how female offspring. Lastly, we investigated the maternal effect on the establishment of the progestational state. A greater number of VMHvl pER alpha immunoreactive cells was found in the pro-oestrous female offspring of low LG mothers and PR was most abundant at pro-oestrus compared to dioestrus in both high and low LG females. Interestingly it is the less receptive high females that show the greater c-Fos expression in the VMH after mating in the pro-oestrous group. The difference in c-Fos expression after mating disappeared when the two groups were ovariectomised and received steroid replacement. Finally, low LG female offspring reached pseudopregnancy more often when receiving only seven intromissions at a 5-min interval compared to high LG females. Lower levels of maternal care may favour the reproductive success of low LG offspring by increasing pER alpha and oestrogen-dependent lordosis behaviour and lowering c-Fos after mating, resulting in inhibition of termination of oestrus.