TY - JOUR
T1 - Stimulation of the hypothalamic paraventricular nucleus produces analgesia not mediated by vasopressin or endogenous opioids
AU - Yirmiya, Raz
AU - Ben-Eliyahu, Shamgar
AU - Shavit, Yehuda
AU - Marek, Przemyslaw
AU - Liebeskind, John C.
PY - 1990/12/24
Y1 - 1990/12/24
N2 - The analgesic effect of electrical stimulation of the hypothalamic paraventricular nucleus (PVN) was studied. Additionally, the involvement of vasopressin and opioid peptides in this process was examined by comparing vasopressin-deficient (Brattleboro) and Long-Evans rats and by administering the opiate antagonist naloxone. Rats were chronically implanted with a stimulating electrode in the parvocellular (PVN-Pc) and magnocellular (PVN-Mg) divisions of the PVN. At least 10 days after surgery, the analgesic effects of PVN stimulation were examined in lightly anesthetized rats, using the tail-flick method, and in unanesthetized rats, using the hot-plate test. PVN stimulation produced marked analgesia in both tests. Current threshold for analgesia was lower from PVN-Pc than from PVN-Mg. Threshold did not differ significantly between Brattleboro and Long-Evans rats and was not affected by naloxone administration. The results indicate that the PVN is part of the brain's pain inhibitory system, and show that the analgesia induced by PVN stimulation is not mediated by either vasopressin or opioid peptides.
AB - The analgesic effect of electrical stimulation of the hypothalamic paraventricular nucleus (PVN) was studied. Additionally, the involvement of vasopressin and opioid peptides in this process was examined by comparing vasopressin-deficient (Brattleboro) and Long-Evans rats and by administering the opiate antagonist naloxone. Rats were chronically implanted with a stimulating electrode in the parvocellular (PVN-Pc) and magnocellular (PVN-Mg) divisions of the PVN. At least 10 days after surgery, the analgesic effects of PVN stimulation were examined in lightly anesthetized rats, using the tail-flick method, and in unanesthetized rats, using the hot-plate test. PVN stimulation produced marked analgesia in both tests. Current threshold for analgesia was lower from PVN-Pc than from PVN-Mg. Threshold did not differ significantly between Brattleboro and Long-Evans rats and was not affected by naloxone administration. The results indicate that the PVN is part of the brain's pain inhibitory system, and show that the analgesia induced by PVN stimulation is not mediated by either vasopressin or opioid peptides.
KW - Brattleboro
KW - Naloxone
KW - Opioid
KW - Pain
KW - Paraventricular nucleus
KW - Rat
KW - Stimulation-produced analgesia
KW - Vasopressin
UR - http://www.scopus.com/inward/record.url?scp=0025598307&partnerID=8YFLogxK
U2 - 10.1016/0006-8993(90)90354-E
DO - 10.1016/0006-8993(90)90354-E
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C2 - 1982239
AN - SCOPUS:0025598307
SN - 0006-8993
VL - 537
SP - 169
EP - 174
JO - Brain Research
JF - Brain Research
IS - 1-2
ER -