[Features of the activation of neurons of the reticular formation of the brain stem in the cat to somatic stimuli of various modality].

Neuronal responses of two reticular structures--nucleus reticularis pontis caudalis (RPC) and nucleus reticularis gigantocellularis (RGC)--to electrical nociceptive stimulation of the internal intercostal nerve and non-nociceptive, tactile stimulation of the skin in the same somatic area have been studied in chloralose anesthetized cats. It was shown that the mean number of action potentials in responses of RPC-neurons to tactile stimulation exceeded that for FGC-neurons by 20-150%. On the opposite, the average number of action potentials in RPC-neurons in response to nerve stimulation was lower by 15-54% than those of bulbar neurons. Data obtained indicate the existence of spatial rostro-caudal differentiation of somatosensory modalities in the reticular brainstem formation.