title: Effect of morphine-induced cortical excitation on somatosensory responses evoked in the periaqueductal grey matter.
abstract: The somatosensory cortex responses and periaqueductal grey matter responses evoked by electric peripheral nerve stimulation were studied following topical application of 1% morphine solution to the primary somatosensory area of rat cerebral cortex. Cortically applied morphine increased the negative component of cortical potentials and enhanced the peak-to-peak amplitude of the periaqueductal grey responses. It is suggested that cortical excitation induced by morphine generates descending bioelectrical impulses modulating neuronal activity at this mesencephalic level.
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009475:Neurons, Afferent / Q000187:drug effects; D010487:Periaqueductal Gray / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013003:Somatosensory Cortex / Q000187:drug effects* / Q000502:physiology
chemical_list: D009270:Naloxone; D009020:Morphine