Behavioral and physiological studies of non-narcotic analgesia in the rat elicited by certain environmental stimuli

摘要: These experiments characterized the analgesia resulting from exposure to certain noxious and/or stressful manipulations. Rats exposed either electric grid shock (0.35-2.0 mA for 10-30 sec) or 5 min of presumably non-painful centrifugal rotation (about 7.0 transverse g's) were analgesic as measured by tail-flick, hot plate and responses applications a calibrated paw pinch alligator clip. Analgesia produced (SA) (RA) persisted after termination these Neither SA nor RA attended generalized sensory, attentional motoric deficits. Intraperitoneal injection hypertonic saline also increased tail-flick latencies. Exposure brief ether anesthesia horizontal oscillation, both which have been reported increase ACTH secretion (a commonly used indicator stress), did not produce test. The use classical conditioning procedures pair with environmental stimuli resulted in narcotic antagonist naloxone (1 mg/kg, i.p.) reduce inhibition shock, rotation, conditioning. Chlordiazepoxide (5 failed antagonize latencies Tail-flick was markedly reduced complete spinal cord transection at thoracic levels. results suggest that: (1) selective modulation nociceptive input level can be mediated supraspinal system systems physiologically distinct those involved administration opiates; (2) non-narcotic occurring within learned procedures; (3) are sufficient but necessary analgesia; stress alone, however, is always this analgesia.