title: Hyperlocomotion and paw tremors are two highly quantifiable signs of SR141716-precipitated withdrawal from delta9-tetrahydrocannabinol in C57BL/6 mice.
abstract: Increasing evidence suggests that marijuana abstinence leads to clinically significant withdrawal symptoms in humans. In mouse models, following chronic treatment with delta9-tetrahydrocannabinol (THC), administration of the selective cannabinoid CB1 receptor antagonist SR141716 (rimonabant) elicited varying behavioral responses, depending on mouse strain and dosing regimen. In the present study, C57BL/6 mice were injected s.c. with THC (25 mg/kg) or vehicle twice daily for 4.5 days. SR141716 (15 mg/kg) was administrated i.p. 4 h following the last THC treatment. During a 2-h observation period immediately following the SR141716 challenge, the total locomotor, ambulatory and stereotypic activities of THC-treated mice were 4.1, 3.3, and 3.8 times those of vehicle-treated mice, respectively. The number of paw tremors elicited in THC-treated mice was 111+/-11 during the 45 min immediately following SR141716, whereas only 1.1+/-0.4 was associated with vehicle-treated animals. In contrast, the number of scratching bouts was higher in vehicle-treated (182+/-20) vs THC-treated (17+/-4) mice. The present study is the first to demonstrate hyperlocomotion as an explicit sign of THC abstinence in mice. Together with paw tremors, the two unambiguous withdrawal signs may permit highly quantitative investigation of THC abstinence in C57BL/6 mice and may facilitate investigation of the mechanisms involved via both pharmacological and genetic manipulations, and ultimately potential treatments for cannabis dependence.
authors.affiliation: Department of Pharmacology and Center for Substance Abuse Research, Temple University School of Medicine, 3420N Broad St, OMS333, Philadelphia, PA 19140, USA. phuang@temple.edu
authors.forename: Peng
authors.initials: P
authors.lastname: Huang
authors.forename: Lee-Yuan
authors.initials: LY
authors.lastname: Liu-Chen
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Unterwald
authors.forename: Alan
authors.initials: A
authors.lastname: Cowan
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D013759:Dronabinol / Q000009:adverse effects* / Q000494:pharmacology; D004409:Dyskinesia, Drug-Induced; D005552:Forelimb / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects; D010880:Piperidines / Q000494:pharmacology; D011619:Psychotropic Drugs / Q000009:adverse effects* / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors; D000077285:Rimonabant; D013375:Substance Withdrawal Syndrome; D014202:Tremor / Q000139:chemically induced
chemical_list: D010880:Piperidines; D011619:Psychotropic Drugs; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D013759:Dronabinol; D000077285:Rimonabant