Antinociceptive action of vaginocervical stimulation in rat spinal cord: 2-DG analysis

Using [14C] 2-deoxyglucose (2-DG) autoradiography with computerized densitometric analysis, unilateral foot pinch was found to significantly increase the relative optical density in laminae I and II of the ipsilateral, compared to the contralateral, spinal cord at lumbar 5 (L5). However, during vaginocervical mechanostimulation applied concurrently with the unilateral foot pinch, no comparable difference was observed. No response to foot pinch was observed in other laminae of the spinal cord at L5, and no effects comparable to the above were observed at L3. These findings indicate that vaginocervical mechanostimulation suppresses neural responses to noxious foot pinch stimulation selectively at the laminae I and II level of the spinal cord at L5, but not at L3.