Electrophysiological effects of propranolol and carbachol locally injected into nucleus raphe dorsalis in cats.
The effect of propranolol and carbachol injected directly into nucleus raphe dorsalis (RD) on the evoked potentials, their recovery cycles and on the spontaneous EEG activity recorded in the RD and the visual and somatosensory cortical regions was investigated. It was found that the changes in these electrophysiological parameters induced by propranolol and carbachol were similar and showed an increase in the excitability level in both the RD and the neocortex, mainly in the somatosensory cortex. The activating effect of carbachol was much more pronounced as compared with that of propranolol. The results are discussed in relation to the possible interactions between various neurotransmitter systems within the RD as well as to the data about the presumed role of this nucleus in some behavioral and/or electrophysiological manifestations. The findings suggest that raphe dorsalis participates in the regulation of the cortical excitability and apparently represents a system which modulates the transMission and integration of sensory information.
D000818:Animals; D001921:Brain / Q000187:drug effects*; D002217:Carbachol / Q000494:pharmacology*; D002415:Cats; D004569:Electroencephalography; D004594:Electrophysiology; D005071:Evoked Potentials / Q000187:drug effects; D007267:Injections; D007545:Isoproterenol / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology*; D011903:Raphe Nuclei
D002217:Carbachol; D011433:Propranolol; D007545:Isoproterenol; D009638:Norepinephrine