Decanoic acid attenuates the excitability of nociceptive trigeminal primary and secondary neurons associated with hypoalgesia.

Background: Acute application of decanoic acid (DA) in vivo suppresses the excitability of spinal trigeminal nucleus caudalis (SpVc) wide dynamic range (WDR) neurons associated with the short-term mechanical hypoalgesia via muscarinic M receptor signaling; however, the effect of DA on nociceptive trigeminal ganglion (TG) and SpVc nociceptive-specific (NS) neuronal excitability under in vivo conditions remains to be determined. The present study investigated whether this effect could be observed in naive rats.

Results: Extracellular single-unit recordings were made from TG and SpVc NS neurons of pentobarbital-anesthetized rats in response to orofacial noxious mechanical stimuli.