R. Cuevarolon et al., VAGOTOMY BLOCKS RESPONSES TO VAGINOCERVICAL STIMULATION AFTER GENITOSPINAL NEURECTOMY IN RATS, Physiology & behavior, 60(1), 1996, pp. 19-24
To ascertain whether any effects of vaginocervical stimulation (VS) ar
e mediated by the vagus nerve, all known afferent nerves from the repr
oductive tract to the spinal cord were transected and the rats were te
sted for residual responses to VS. After combined bilateral transectio
n of the pelvic, hypogastric, and pudendal nerves (NX), the following
responses to VS were greatly reduced or abolished: lordosis to flank-p
erineum palpation, leg extension, immobilization, and blockage of both
tail withdrawal to radiant heat and leg withdrawal to foot pinch. How
ever, after these nerve cuts, the following persisted as significant r
esidual responses to VS: 1) analgesia [measured as increase in vocaliz
ation threshold (VOCT) to tailshock], 2) pupil dilatation (PD), and 3)
increase in heart rate (HR). Subsequent bilateral subdiaphragmatic va
gotomy (VX) significantly reduced the magnitude of PD and abolished th
e analgesia. By contrast, VX produced no significant effect on the HR
increase to VS. The above findings provide evidence that brain-mediate
d responses to vaginocervical stimulation can be elicited via the vagu
s nerves.