A mechanism of carbamazepine-analgesia as shown by bradykinin-induced trigeminal pain.

Single neuronal responses induced by micro-application of bradykinin solution to the tooth pulp of the rabbit were recorded in the subnucleus reticularis dorsalis and trigeminal subnucleus caudalis and characterized by intermittent episodes of paroxysmal activities. Carbamazepine, the primary agent for trigeminal neuralgia, suppressed such a paroxysmal response, suggesting that an analgesic action of the drug results from the suppression of synaptic transmission at the subnucleus reticularis dorsalis and trigeminal subnucleus caudalis.