Evidence for a direct projection from the paraventricular nucleus of the hypothalamus to putative serotoninergic neurons of the nucleus paragigantocellularis involved in the control of erection in rats
Evidence for a direct projection from the paraventricular nucleus of the hypothalamus to putative serotoninergic neurons of the nucleus paragigantocellularis involved in the control of erection in rats
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DOI：
10.1046/j.1460-9568.2002.02184.x
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发表时间：
2002-10-01
影响因子：
3.4
通讯作者：
Vergé, D
中科院分区：
文献类型：
--
作者：
Bancila, M;Giuliano, F;Vergé, D
在雄性大鼠中，延髓腹外侧区的肾上腺素能神经元向支配阴茎的脊髓节前神经元发出直接投射。下丘脑室旁核在控制阴茎勃起中的作用已被广泛认识。我们的目的是证明室旁神经元和延髓肾上腺素能神经元支配阴茎之间的解剖关系。在成年雄性大鼠的室旁核进行立体定位离子电渗注射菜豆白细胞凝集素。在延髓腹外侧区的神经元逆行标记使用注射在海绵体中的伪狂犬病病毒的transneuronal逆行运输。用特异性抗体对延髓腹外侧切片进行双重免疫荧光处理，以显示菜豆白细胞凝集素和伪狂犬病病毒。还对切片进行处理，以同时检测伪狂犬病病毒和5-羟色胺。延髓腹外侧区的伪狂犬病毒感染神经元主要分布于巨细胞旁核、延髓网状结构、中缝苍白核和中缝大核。在巨细胞旁核，所有伪狂犬病毒感染的神经元免疫反应5-羟色胺。其中一些接受了菜豆白细胞凝集素标记的静脉曲张纤维，这些纤维沿着伪狂犬病病毒感染神经元的索马。共聚焦显微镜表明它们之间存在几个密切的并列，这是证明了使用三维重建的系列光学切片。我们的研究结果表明，室旁核神经元发送直接投射到神经支配阴茎的旁巨细胞核神经元。他们认为室旁核可能通过控制下行的肾上腺素能中缝核脊髓神经元在阴茎勃起中发挥作用。在这一通路中使用的神经递质仍有待确定。
In the male rat, serotoninergic neurons of the ventrolateral medulla send direct projections onto spinal preganglionic neurons that innervate the penis. The role of the paraventricular nucleus of the hypothalamus in the control of penile erection is well recognized. Our aim was to demonstrate anatomical relation between paraventricular neurons and medullary serotoninergic neurons innervating the penis. In adult male rats, stereotaxic iontophoretic injections of Phaseolus vulgaris leuco-agglutinin were performed in the paraventricular nucleus. Neurons in the ventrolateral medulla were retrogradely labelled using transneuronal retrograde transport of pseudorabies virus injected in the corpus cavernosum. Sections of the ventro-lateral medulla were processed for double immunofluorescence to reveal both Phaseolus vulgaris leuco-agglutinin and pseudorabies virus using specific antibodies. Sections were also processed for the simultaneous detection of pseudorabies virus and serotonin. Pseudorabies virus-infected neurons in the ventrolateral medulla were present in the nucleus paragigantocellularis, reticular formation of the medulla, raphe pallidus and raphe magnus. In the nucleus paragigantocellularis, all pseudorabies virus-infected-neurons were immunoreactive for serotonin. Some of them received Phaseolus vulgaris leuco-agglutinin-labelled varicose fibres that ran along the soma of pseudorabies virus-infected neurons. Confocal microscopy suggested the presence of several close appositions between them, which were demonstrated using three-dimensional reconstruction of serial optical sections. Our results show that paraventricular neurons send direct projections in the nucleus paragigantocellularis onto neurons that innervate the penis. They suggest a possible role of the paraventricular nucleus in penile erection through the control of descending serotoninergic raphe-spinal neurons. The neurotransmitter used in this pathway remains to be determined.