Psychopharmacology (Berl). 2013 Mar 13. [Epub ahead of print]
Dissociable effects of CB1 receptor blockade on anxiety-like and consummatory behaviors in the novelty-induced hypophagia test in mice.
Gamble-George JC, Conger JR, Hartley ND, Gupta P, Sumislawski JJ, Patel S.
Department of Psychiatry, Vanderbilt University School of Medicine, Robinson Research Building, Rm 724B, Nashville, TN, 37212, USA.
RATIONALE:
Central CB1 cannabinoid receptors regulate anxiety-like and appetitive consummatory behaviors. Pharmacological antagonism/inverse-agonism of CB1 receptors increases anxiety and decreases appetitive behaviors; however, neither well-defined dose nor context dependence of these effects has been simultaneously assessed in one behavioral assay.
OBJECTIVES:
We sought to determine the context and dose dependence of the effects of CB1 receptor blockade on anxiety-like and consummatory behaviors in a model that allowed for simultaneous detection of anxiety-like and consummatory-related behaviors.
METHODS:
We determined the effects of the CB1 receptor antagonist/inverse-agonist, rimonabant, in the novelty-induced hypophagia (NIH) assay in juvenile male ICR mice.
RESULTS:
Rimonabant dose-dependently decreased consumption of a palatable reward solution completely independent of contextual novelty. Grooming and scratching behavior was also increased by rimonabant in a context-independent manner. In contrast, rimonabant increased feeding latency, a measure of anxiety-like behaviors, only in a novel, mildly anxiogenic context. The effects of rimonabant were specific since no effects of rimonabant on despair-like behavior were observed in the tail suspension assay. Blockade of CB2 receptors had no effect on novelty-induced increases in feeding latency or palatable food consumption.
CONCLUSIONS:
Our findings indicate that CB1 receptor blockade decreases the hedonic value of palatable food irrespective of environmental novelty, whereas the anxiogenic-like effects are highly context-dependent. Blockade of CB2 receptors does not regulate either anxiety-like or consummatory behaviors in the NIH assay. These findings suggest that rimonabant modulates distinct and dissociable neural processes regulating anxiety and consummatory behavior to sculpt complex and context-dependent behavioral repertories.
Duh! Just distribute a well-designed survey, at the local patient collective. No need to torture mice. |
