[The role of opioids in mediating the antinociceptive influences of hypothalamic "pleasure zones"].
In 41-60-day old rabbits, the antinociceptive effect of stimulation of the hypothalamic "rewarding areas" was estimated by a decrease in the EPs' amplitude as recorded in the thalamus' parafascicular complex in response to nociceptive stimulation of a hind-limb. The EPs were inhibited at a certain power of the current stimulating the "rewarding areas" in all the animals. In complete inhibition of nociceptive EPs, low doses of naloxone weakened it in 4 rabbits out of 6, whereas high doses only weakened it in 1 animal out of 4. In incomplete inhibition of the EPs, low doses of naloxone enhanced the antinociceptive effect up to complete suppression of EPs in 3 cases out of 6, whereas high doses did not affect this effect in 5 cases out of 7. Neurochemical mechanisms of the EPs inhibition in unspecific nociceptive complex of the thalamus during stimulation of hypothalamic "rewarding areas", are discussed.
Butkevich
I P
IP
Mikhaĭlenko
V A
VA
Kassil'
V G
VG
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004723:Endorphins / Q000187:drug effects / Q000502:physiology*; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects / Q000502:physiology*; D011817:Rabbits; D012201:Reward; D012653:Self Stimulation / Q000187:drug effects / Q000502:physiology*
D004723:Endorphins; D009270:Naloxone
Rol' opioidov v oposredovanii antinotsitspetivnykh vliianiĭ gipotalamicheskikh "zon nagrady".