Pharmacological effects of cannabinoids on the reference and working memory functions in mice.
BACKGROUND
Evidence indicates cannabinoid receptor agonists impair performance in procedures to assess memory that may also be confounded by motivational or motor effects, both of which occur with cannabinoids. Thus, convergence of evidence from a variety of procedures that differ in motivation, attention, arousal and response requirements, but share a common reliance on memory, is required. There are no current reports on cannabinoid effects on mice tested in the radial arm maze.


OBJECTIVE
The objective was to determine the effects of the cannabinoid agonist CP 55940 and the dependence of any such effects on the CB1 receptor using the CB1 receptor antagonist SR 141716A on two strains of mice in the eight-arm radial maze procedure.


METHODS
Male C57BL/6J (N = 36) and C3H/HEJ (N = 12) mice were trained to a criterion and then were treated (IP) with vehicle + vehicle, SR 141716A + vehicle, vehicle + CP 55940 and SR 141716A + CP 55940 in a fully balanced mixed design prior to further tests in the maze. Reference (long-term) and working (short-term) memory were assessed.


RESULTS
CP 55940 impaired performance of the reference memory task in the C57BL/6J strain but not the C3H/HEJ strain; SR 141716A reversed the effect of CP 55940 on these measures. CP 55940 also increased working memory errors in the C57BL/6J mice only, which was not affected by SR 141716A.


CONCLUSIONS
The present study provides evidence for a strain-specific effect of a dose of CP 55940 on reference memory. While the cannabinoid agonist also impaired working memory in one strain, this effect was apparently not mediated by CB1 receptors.
Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Perth, Western Australia, Australia. chaudharyavdesh@gmail.com
Avdesh
A
Avdesh
Yikai
Y
Hoe
Ralph N
RN
Martins
Mathew T
MT
Martin-Iverson
D000818:Animals; D063386:Cannabinoid Receptor Agonists / Q000494:pharmacology; D063387:Cannabinoid Receptor Antagonists / Q000494:pharmacology; D002186:Cannabinoids / Q000494:pharmacology*; D003511:Cyclohexanols / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D043884:Receptor, Cannabinoid, CB1 / Q000187:drug effects / Q000378:metabolism*; D000077285:Rimonabant; D013045:Species Specificity
D063386:Cannabinoid Receptor Agonists; D063387:Cannabinoid Receptor Antagonists; D002186:Cannabinoids; D003511:Cyclohexanols; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; C054649:3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol; D000077285:Rimonabant