Stimulation-produced and stress-induced analgesia: cross-tolerance between opioid forms.
Electrical stimulation of medial brainstem sites produces potent analgesia in rats that is either opioid- or non-opioid-mediated depending on the specific brain region stimulated. Footshock stress also causes opioid and non-opioid forms of analgesia in rats depending on the exact parameters of footshock administered. We now report that opioid, but not non-opioid, stress analgesia demonstrates cross-tolerance with opioid, but not non-opioid, stimulation-produced analgesia. This finding suggests that opioid forms of stimulation-produced and stress-induced analgesia share a common substrate.
D000818:Animals; D001931:Brain Mapping; D001933:Brain Stem / Q000503:physiopathology*; D004558:Electric Stimulation; D004597:Electroshock; D004723:Endorphins / Q000502:physiology*; D008297:Male; D009433:Neural Inhibition; D010146:Pain / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012684:Sensory Thresholds; D013312:Stress, Physiological / Q000503:physiopathology*
D004723:Endorphins