Effects of naloxone and repeated stimulus presentation on cortical somatosensory evoked potential (SEP) amplitude in the rat.
The effects of naloxone (1 mg/kg) and of repeated stimulus presentation were investigated on a cortical somatosensory evoked potential elicited by innocuous stimulation of the spinal trigeminal tract in awake, minimally restrained rats. The amplitude of an early cortical component (9-ms latency) habituated after administration of saline but did not habituate after naloxone. Naloxone also enhanced the response decrement of late somatosensory evoked potential components (60 to 120 ms) produced by repeated stimulation. The amplitude of midlatency components (14 to 50 ms) did not change after administration of saline and repeated stimulus presentation. However, the amplitude of these components increased after administration of naloxone and repeated stimulus presentation.
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D004723:Endorphins / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D006185:Habituation, Psychophysiologic / Q000502:physiology; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D004723:Endorphins; D009270:Naloxone; D009020:Morphine