| Abstract No.: | C-D3158 |
| Country: | Morocco |
| | |
| Title: | SPINAL CORD AND MEDULLA SENSITIVE AFFERENT MESSAGES INDUCED BY VAGINOCERVICAL STIMULATION |
| | |
| Authors/Affiliations: | 1 Nadia Zouhairi*; 1 Abderrazzak Ghanima; 1 Saadia Ba M'hamed; 1 Mohamed Bennis;
1 Faculty of Sciences Semlalia, Marrakech, Morocco
|
| | |
| Content: | Innervation of female genital tract is ensured by the autonomic nervous system constituted by sensitive and motoric pelvic and hypogastric nerve connecting genital tract to spinal cord or medulla.
Stimulation of female genital tract as vaginocevical stimulation (VCS) has been reported to produce a variety of responses including multimodal analgesia and other behavioural, autonomic and neuroendocrine responses. The vagus nerve is also involved in the sensory activity of the reproductive tract in female rats and in women, bypassing the spinal cord and its activation by vaginal or cervical stimulation can evidently attenuate pain, and also induces orgasm in women.
The present study examined the influence of the reflexive vaginocervical activity on the sensitive flux towards the thoraco-lumbar spinal cord and medulla following artificial mechanical vaginocervical stimulation, using immunodetection of Fos, as endogenous marker of neural activity. The experiment was performed in animals which received or not a chemical efferent sympathetic or parasympathetic denervation (guanethidine, hexamethonium and atropine).
The result showed that thoraco-lumbar Fos labelling was highly increased in vaginocervical stimulated rats relative to control. Superficial and intermediolateral dorsal horn contained more neurons than other spinal areas (dorsal grey commissure, sacral parasympathetic nucleus, and ventral horn). Concerning the treated and untreated females with chemical denervation, the results show no significant difference in the number of Fos-immunoreactive neurons in different spinal cord segments and in the NTS (Nucleus tractus solitary) following vaginocervical stimulation.
The results of the present work indicate that the sensitive message projecting to the spinal cord and to the central nervous system, could have an analgesic effect as shown by Komisaruk et al (2003). This analgesic effect is not influenced by both cholinergic and adrenergic systems, responsible for the classical innervation of the genital tract, since the chemical denervation are not influenced the message towards the spinal cord. Otherwise, the no significant change in the expression of number of Fos immunorective neurons in the NTS after this denervation could be in favor of the intervention of other neurotransmitters in the transmission of the sensitive message (analgesic effect).
Multiple neurotransmitters and neuromodulators contribute to VCS-produced analgesia: VIP, norepinephrine, 5-HT, GABA, glycine, and enkephalins. The analgesic effect of VCS can be intensified by estrogen and the NMDA receptor inhibitor AP-5, Komisaruk et al (2003). In addition neuropeptides as NPY and VIP could be incriminated in afferent flux to the spinal cord, because it has been admitted that these peptides are implicated in the control of the contraction or the relaxation of female genital tract, Houdeau et al (1997).
|
| | |
| Back |
|
