title: Body region shocked need not critically define the neurochemical basis of stress analgesia.
abstract: Both opioid and non-opioid forms of stress-induced analgesia have been demonstrated in rats, although the conditions leading to their selective activation are still being investigated. We have shown that variations in shock intensity, duration or temporal pattern can determine whether opioid or non-opioid stress analgesia occurs. Others have suggested that body region shocked is the critical determinant, analgesia from front paw shock being opioid and that from hind paw shock non-opioid. We now report that either opioid or non-opioid stress analgesia can be evoked from either front or hind paws depending only on footshock intensity when duration and temporal pattern are held constant.
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000503:physiopathology*; D004597:Electroshock; D004723:Endorphins / Q000502:physiology*; D005552:Forelimb; D006614:Hindlimb; D008297:Male; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004723:Endorphins