Véronneau-Longueville F, Rampin O, Freund-Mercier M J, Tang Y, Calas A, Marson L, McKenna K E, Stoeckel M E, Benoit G, Giuliano F
Groupe de Recherche en Urologie, Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre, France.
Neuroscience. 1999;93(4):1437-47. doi: 10.1016/s0306-4522(99)00262-6.
In the rat, spinal autonomic neurons controlling penile erection receive descending pathways that modulate their activity. The paraventricular nucleus of the hypothalamus contributes oxytocinergic fibers to the dorsal horn and preganglionic sympathetic and parasympathetic cell columns. We used retrograde tracing techniques with pseudorabies virus combined with immunohistochemistry against oxytocin and radioligand binding detection of oxytocinergic receptors to evidence the oxytocinergic innervation of thoracolumbar and lumbosacral spinal neurons controlling penile erection. Spinal neurons labelled with pseudo-rabies virus transsynaptically transported from the corpus cavernosum were present in the intermediolateral cell column and the dorsal gray commissure of the thoracolumbar and lumbosacral spinal cord. Confocal laser scanning microscopic observation of the same preparations revealed close appositions between oxytocinergic varicosities and pseudorabies virus-infected neurons, suggesting strongly the presence of synaptic contacts. Electron microscopy confirmed this hypothesis. Oxytocin binding sites were present in the superficial layers of the dorsal horn, the dorsal gray commissure and the intermediolateral cell column in both the thoracolumbar and lumbosacral segments. In rats, stimulation of the paraventricular nucleus induces penile erection, but the link between the nucleus and penile innervation remains unknown. Our findings support the hypothesis that oxytocin, released by descending paraventriculo-spinal pathways, activates proerectile spinal neurons.
在大鼠中，控制阴茎勃起的脊髓自主神经元接受调节其活动的下行通路。下丘脑室旁核向背角以及节前交感和副交感神经细胞柱投射催产素能纤维。我们使用伪狂犬病病毒逆行追踪技术，结合针对催产素的免疫组织化学和催产素能受体的放射性配体结合检测，来证明控制阴茎勃起的胸腰段和腰骶段脊髓神经元的催产素能神经支配。从海绵体经突触转运伪狂犬病病毒标记的脊髓神经元存在于胸腰段和腰骶段脊髓的中间外侧细胞柱和背侧灰质连合中。对相同标本进行共聚焦激光扫描显微镜观察发现，催产素能曲张体与伪狂犬病病毒感染的神经元紧密相邻，强烈提示存在突触联系。电子显微镜证实了这一假设。在胸腰段和腰骶段，背角浅层、背侧灰质连合和中间外侧细胞柱均存在催产素结合位点。在大鼠中，刺激室旁核可诱导阴茎勃起，但该核与阴茎神经支配之间的联系仍然未知。我们的研究结果支持这样的假设，即由室旁核 - 脊髓下行通路释放的催产素激活促进勃起的脊髓神经元。
