title: Evidence that the opiate receptors of the substantia gelatinosa contribute to the depression, by intravenous morphine, of the spinal transmission of impulses in unmyelinated primary afferents.
abstract: In barbiturate anaesthetized cats, dorsal horn neurones were excited by electrical stimulation of the common tibial nerve. The numbers of action potentials evoked by excitation of C fibres were depressed by analgesic doses of morphine (1-4 mg/kg i.v.). Naloxone, administered electrophoretically in the substantia gelatinosa, fully reversed the inhibitory action of morphine. The results suggest that opiate receptors in the substantia gelatinosa play a role in morphine analgesia.
mesh_terms: D000344:Afferent Pathways / Q000187:drug effects; D000818:Animals; D002415:Cats; D003864:Depression, Chemical; D005071:Evoked Potentials / Q000187:drug effects; D005727:Ganglia, Spinal / Q000187:drug effects; D009020:Morphine / Q000494:pharmacology*; D009412:Nerve Fibers / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects; D009619:Nociceptors / Q000187:drug effects; D011957:Receptors, Opioid / Q000187:drug effects*; D013116:Spinal Cord / Q000187:drug effects*; D013376:Substantia Gelatinosa / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*; D013979:Tibial Nerve / Q000187:drug effects
chemical_list: D011957:Receptors, Opioid; D009020:Morphine