Effects of noxious stimuli on neurons of the lateral reticular nucleus region in rabbits.
The responses of neurons in the lateral reticular nucleus region (LRN) to both noxious spinal (radiant heat) and trigeminal inputs (tooth pulp stimulation), were analyzed in 12 anesthetized and paralyzed rabbits. It was found that 20% of neurons tested were affected by one or both noxious stimuli and 58% of these cells could be antidromically activated by stimulation of the cerebellum. In the majority of cell (85% of the heat-responding, and 72% of the tooth pulp-responding) the effect of noxious stimuli was excitatory and in the remaining cells was inhibitory. Furthermore 53% of responding neurons showed a convergence to spinal and trigeminal input. The type of response was the same (excitation) in 63% of these units, but was different in the others. These data support the view of an involvement of the LRN region in the mechanisms of the nociceptive information and suggest the possibility that the cerebellum may also contribute to some aspects of these mechanisms.
D000818:Animals; D003782:Dental Pulp / Q000294:innervation; D004558:Electric Stimulation; D005071:Evoked Potentials; D006358:Hot Temperature; D009474:Neurons / Q000145:classification / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000503:physiopathology; D011817:Rabbits; D012018:Reflex / Q000502:physiology; D012154:Reticular Formation / Q000502:physiology*