Title
Effects of Opioid Antagonists on Unconditioned and Conditioned Hyperactivity to Morphine
Document Type
Article
Publication Date
10-2002
Department
Psychology
Language
English
Publication Title
Pharmacology Biochemistry and Behavior
Abstract
In a series of experiments, the ability of selective μ- (β-funaltrexamine, β-FNA), δ- (naltrindole, nalt) and κ- (nor-binaltorphimine, nor-BNI) opioid receptor antagonists to attenuate the unconditioned and conditioned hyperactive effects of morphine was examined. For comparison, the nonselective opioid receptor antagonist naloxone (nalx) was also examined. Locomotor activity served as the behavioral measure. Experiment 1 found that doses of 1 and 4, but not 16 mg/kg, of morphine effectively produced conditioned hyperactivity (CH). Experiments 2a–d found that β-FNA, nalt, nor-BNI and nalx, respectively, attenuated unconditioned morphine-induced hyperactivity. Experiments 3a–c, however, found that none of the selective antagonists, given individually, attenuated CH. In contrast, nalx did attenuate CH (Experiment 3d). Collectively results suggest that the unconditioned and conditioned hyperactive responses to morphine are mediated by different receptor systems and that activation of multiple opioid-receptor subtypes mediate expression of CH.
DOI
10.1016/S0091-3057(02)00855-9
Recommended Citation
Rauhut, Anthony S., Brenda J. Gehrke, Scott B. Phillips, and Michael T. Bardo. "Effects of Opioid Antagonists on Unconditioned and Conditioned Hyperactivity to Morphine." Pharmacology Biochemistry and Behavior 73, no. 3 (2002): 611-622.
Comments
For more information on the published version, visit Science Direct's Website.