Penile erection is due to activation of proerectile neurons located in the sacral parasympathetic nucleus of the L6-S1 spinal cord in the @entity35 . Contraction of the ischiocavernosus and bulbospongiosus striated muscles, controlled by motoneurons located in the ventral horn of the L5-L6 spinal cord, reinforces penile erection. Physiological and pharmacological arguments have been provided for a role of @entity398 and @entity750 in the spinal regulation of penile erection. Immunohistochemistry of oxytocinergic and serotonergic fibres was performed at the lumbosacral level of the male @entity35 spinal cord, and combined with retrograde tracing from the pelvic nerve or from the ischiocavernosus and bulbospongiosus muscles using @entity3505 germ agglutinin-horseradish @entity3698 . Sacral preganglionic neurons retrogradely labelled from the pelvic nerve formed a homogeneous population, predominant at the L6 level. Motoneurons retrogradely labelled from the ischiocavernosus and bulbospongiosus muscles were observed in the medial part of the dorsolateral and in the dorsomedial nuclei. Fibres immunoreactive for @entity398 were mainly distributed in the superficial layers of the dorsal horn, the dorsal gray commissure and the sacral parasympathetic nucleus. Some of these fibres were apposed to retrogradely-labelled sacral preganglionic neurons and at the ultrastructural level, some synapses were evidenced. Fibres immunoreactive for @entity750 were largely and densely distributed in the dorsal horn, the dorsal gray commissure, the sacral parasympathetic nucleus and the ventral horn. Some serotonergic fibres occurred in close apposition with retrogradely-labelled sacral preganglionic neurons and motoneurons, and synapses were demonstrated at the ultrastructural level. This study provides morphological support for a role of @entity398 and @entity750 on sacral preganglionic neurons innervating pelvic organs and motoneurons innervating the ischiocavernosus and bulbospongiosus muscles.

Oxytocinergic and serotonergic innervation of identified lumbosacral nuclei controlling penile erection in the male XXXX .

@entity398 :: ('MESH:D010121', 'Chemical') :: ['oxytocin'] @entity3505 :: ('4565', 'Species') :: ['wheat'] @entity3698 :: ('543313(Tax:4565)', 'Gene') :: ['peroxidase'] @entity750 :: ('MESH:D012701', 'Chemical') :: ['serotonin'] @entity35 :: ('10116', 'Species') :: ['rat']
@entity35 :: (10116,Species) :: ['rat']
