Brain structures mediating the suckling stimulus-induced release of prolactin
Brain structures mediating the suckling stimulus-induced release of prolactin
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DOI：
10.1046/j.0007-1331.2002.00789.x
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发表时间：
2002-05-01
影响因子：
3.2
通讯作者：
Halász, B
中科院分区：
文献类型：
--
作者：
Bodnár, I;Bánky, ZS;Halász, B
哺乳诱导的催乳素释放是一种被广泛研究的神经内分泌反射，包括神经传入和体液传出成分。有关这种反射的大脑结构的信息相当有限。目前的研究主要集中在这个问题上。对哺乳期大鼠的下丘脑进行了以下干预，并测试了哺乳诱导的泌乳素反应：(i)单侧或（ii）双侧下丘脑前部和后部水平的额部切割；（iii）给药5,7-二羟色胺或（iv） 6-羟多巴胺进入下丘脑室旁核（PVN），分别破坏细胞组的血清素能和儿茶酚胺能神经支配；(v) PVN内侧亚段病变；（vi） PVN以下的水平刀切。双侧后、双侧或单侧额前切口可阻断哺乳诱导的催乳素释放。同样，大多数在PVN中接受5,7-二羟色胺的母鼠对哺乳刺激没有反应。免疫细胞化学显示，在那些血浆催乳素没有增加的大鼠中，PVN中几乎没有血清素能纤维和末端，而在表现出反应的大坝中，大量的血清素能元素是明显的。6-羟多巴胺治疗未引起泌乳素反应的显著改变。内侧的病变，主要是PVN的旁细胞亚分裂，或该细胞群下方的水平刀切，阻断了激素反应。研究结果首次证明：(1)脑干和下丘脑之间的连接中断会干扰哺乳刺激对泌乳素的反应；（ii）终止于下丘脑PVN的血清素能纤维参与了哺乳刺激的调解；（iii）在PVN内，位于细胞群内侧的神经元参与神经信号的传递，最终诱导泌乳素的释放。
Suckling-induced prolactin release is a widely studied neuroendocrine reflex, comprising a neural afferent and a humoral efferent component. The information on the brain structures involved in this reflex is fairly limited. The present studies focused on this question. The following hypothalamic interventions were made in lactating rats and the dams were tested for the suckling-induced prolactin response: (i) unilateral or (ii) bilateral frontal cuts at the level of the anterior and posterior hypothalamus; (iii) administration of 5,7-dihydroxytryptamine or (iv) 6-hydroxydopamine into the hypothalamic paraventricular nucleus (PVN) to destroy serotonergic and catecholaminergic innervation of the cell group, respectively; (v) lesion of the medial subdivision of the PVN; and (vi) horizontal knife cuts below the PVN. Bilateral posterior and bilateral or unilateral anterior frontal cuts caused blockade of the suckling-induced release of prolactin. Likewise, most dams receiving 5,7-dihydroxytryptamine in the PVN did not respond to the suckling stimulus. Immunocytochemistry revealed that, in those rats which did not show a rise in plasma prolactin, there were almost no serotonergic fibres and terminals in the PVN, while in dams which exhibited a response, numerous serotonergic elements were evident. 6-Hydroxydopamine treatment did not cause significant alteration in the prolactin response. Lesion of the medial, largely parvocellular subdivision of the PVN, or horizontal knife cuts below this cell group, blocked the hormone response. The findings demonstrate for the first time that: (i) interruption of the connections between the brain stem and the hypothalamus interferes with the prolactin response to the suckling stimulus; (ii) serotonergic fibres terminating in the hypothalamic PVN are involved in the mediation of the suckling stimulus; and (iii) within the PVN, neurones in the medial, largely parvocellular subdivision of the cell group take part in the transfer of the neural signal, eventually inducing prolactin release.