Neural pathways mediating vaginal function: the vagus nerves and spinal cord oxytocin.
The initial observations, made in our laboratory with Knut Larsson, of the ability of vaginocervical stimulation (VCS) to block withdrawal responses to foot pinch in rats has led to findings of multiple behavioral, autonomic, and neuroendocrine effects of this potent stimulus in rats and also in women. It has led to an understanding of: (1) the neuroanatomical and neurochemical basis of a novel and potent pain-blocking mechanism; (2) likely neuroanatomical pathways mediating both the Ferguson reflex and a specific autonomic response - the pupil-dilating effect of VCS; (3) a role for oxytocin as a putative central nervous system neurotransmitter that stimulates autonomic sympathetic preganglionic neurons within the spinal cord; and (4) a novel pathway that can convey sensory activity from the cervix, adequate to induce orgasm, via the vagus nerves. This latter pathway bypasses the spinal cord and projects directly to the medulla oblongata, and thus can convey genital afferent activity despite complete spinal cord injury at any level.
Komisaruk
Barry R
BR
Department of Psychology and Biological Sciences, Rutgers, The State University of New Jersey, Newark, New Jersey 07102, USA. komisarb@nigms.nih.gov
Sansone
Giorgio
G
D000818:Animals; D005260:Female; D006801:Humans; D009434:Neural Pathways / Q000502:physiology*; D010121:Oxytocin / Q000502:physiology*; D051381:Rats; D013116:Spinal Cord / Q000502:physiology*; D014621:Vagina / Q000294:innervation* / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology*
D010121:Oxytocin