PT  - JOURNAL ARTICLE
AU  - E Wei
AU  - S S Sigel
AU  - H H Loh
AU  - E L Way
TI  - Central sites of naloxone-precipitated shaking in the anesthetized, morphine-dependent rat.
DP  - 1975 Dec 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 480--487
VI  - 195
IP  - 3
4099  - http://jpet.aspetjournals.org/content/195/3/480.short
4100  - http://jpet.aspetjournals.org/content/195/3/480.full
SO  - J Pharmacol Exp Ther1975 Dec 01; 195
AB  - Naloxone hydrochloride, an opiate antagonist, administered via the intracranial or parenteral route precipitates shaking behavior in the morphine-dependent rat. We made localized bilateral injections of naloxone HCl, 1.5 mug/rat, into 60 subcortical sites of the pentobarbital-anesthetized, morphine-dependent rat and found that two circumscribed areas of the brain, the medial hypothalamus and the periaqueductal-4th ventricular spaces, were selectively sensitive to naloxone-precipitated shaking. In the nondependent rat, morphine injections into the anterior diencephalon inhibited the shaking response to ice water; injections of morphine into the medial diencephalon were less effective. However, naloxone antagonized the morphine-inhibited shaking more effectively when injections of naloxone were made in the medial diencephalon than when injections were made in the anterior diencephalon. These results suggest that the reciprocal relationship of morphine and morphine-naloxone effects on shaking behavior may be regulated by topographically different structures in the diencephalon.