Suppression of tooth pulp evoked responses by activation of raphe-trigeminal neurons in rat

Electrical stimulation (0.1 msec duration, 50 Hz, 1 min) applied to the nucleus raphe magnus markedly suppressed the tooth pulp evoked responses in caudal part of the spinal trigeminal nucleus but only slightly altered those in its rostral area. Raphe stimulation also greatly suppressed jaw opening reflex evoked by tooth pulp stimulation, which lasted longer than suppression of spinal trigeminal nucleus.