Lack of habituation of pain evoked potentials after naloxone.
Pain evoked potentials (EPs) were recorded in nucleus caudatus (NC) of rabbits after electric stimulation of the dental pulp. After 50--60 noxious stimuli the decrease in amplitude of evoked potentials occured. Naloxone, 1 mg/kg, temporarily abolished this effect and even after 350 noxious stimuli the habituation was not observed. On the other hand, naloxone did not affect the diminution of monosynaptic transcallosal potentials (TC--EP) evoked by repeated stimulation. It may be suggested that the habituation of EPs elicited by pain stimulation is due to endorphin release.
D000818:Animals; D003782:Dental Pulp / Q000502:physiology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D006185:Habituation, Psychophysiologic / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology*; D011817:Rabbits
D009270:Naloxone