Brain (PET) responses to vaginal-cervical self-stimulation in women with complete spinal cord injury: preliminary findings.

Our recent research provides evidence that women with complete spinal cord injury (SCI) at the midthoracic level show perceptual responses to vaginal and/or cervical self-stimulation (for example, pain suppression and sexual response, including orgasm). On the basis of studies in laboratory rats, we hypothesized that the vagus nerves provide a sensory pathway from the vagina, cervix, and uterus directly to the brain in women. To test this hypothesis, we performed a PET-MRI study on two women with complete SCI and 1 woman with no injuries. Whereas control foot stimulation of the women with SCI did not activate the somatosensory thalamus, cervical self-stimulation increased activity in the region of the nucleus of the solitary tract, which is the brainstem nucleus to which the vagus nerves project. These preliminary findings suggest that the vagus nerves can convey genital sensory input directly to the brain in women, completely bypassing SCI at any level.