Doctorado en Ciencias Biomédicas, CIB, Universidad Veracruzana, Xalapa, Veracruz, México.
Centro de Investigaciones Biomédicas, Universidad Veracruzana, Av. Luis Castelazo s/n, Col. Industrial Animas, C.P. 91190, Xalapa, Veracruz, México.
Eur J Neurosci. 2017 Jun;45(11):1396-1409. doi: 10.1111/ejn.13571. Epub 2017 Apr 26.
Maternal care is a motivated behavior and in the rabbit it is restricted to the spontaneous return of the mother to nurse her pups for just a few minutes once a day. Previously we have reported neural activation of brain areas and neuroendocrine cells after nursing. However, this daily spontaneous return suggests that the mother is in a high motivational state to nurse her pups. Here we hypothesized that during anticipation of nursing there is an activation of dopaminergic neurons of the mesolimbic system and in their target areas. Then we explored, by the expression of FOS protein, possible activation of the mesolimbic system as well as dopaminergic cells of the A10 cell group before and after nursing and in control does. Additionally, we measured FOS expression in the preoptic area and lateral septum. We found a significant increase of FOS before nursing, and a further increase after nursing, in the mesolimbic system and dopaminergic cells as well as in the preoptic area and lateral septum. Interestingly, the medial prefrontal area shows an intense activation during anticipation of nursing, which remains after nursing. We conclude that the activation of the mesolimbic system before nursing is related to the high locomotor behavior prior to the next nursing bout and support the proposal that the mother is in a high motivational state at the time of returning to the nest. The additional activation after nursing can be related to the neuroendocrine and neural consequences of the milk ejection reflex by suckling.
母性行为是一种动机行为，在兔子中，它仅限于母亲每天自发地回到巢穴中给幼崽哺乳几分钟。之前我们已经报道了哺乳后大脑区域和神经内分泌细胞的神经激活。然而，这种每天的自发回归表明，母亲处于一种高度的哺乳动机状态。在这里，我们假设在哺乳前存在中脑边缘多巴胺能神经元及其靶区的激活。然后，我们通过 FOS 蛋白的表达，探索了在哺乳前和哺乳后以及对照组中，中脑边缘系统以及 A10 细胞群中的多巴胺能细胞是否可能被激活。此外，我们还测量了视前区和外侧隔核中的 FOS 表达。我们发现，在中脑边缘系统和多巴胺能细胞以及视前区和外侧隔核中，FOS 在哺乳前显著增加，在哺乳后进一步增加。有趣的是，内侧前额叶区域在哺乳前的期待中表现出强烈的激活，这种激活在哺乳后仍然存在。我们得出结论，在哺乳前中脑边缘系统的激活与下一次哺乳前的高运动行为有关，并支持这样的观点，即母亲在回到巢穴时处于高度的动机状态。哺乳后的额外激活可能与吸吮引起的射乳反射的神经内分泌和神经后果有关。
