In the present study, whereas the CB1 receptor antagonist rimonabant blocked the anxiolytic effects of PF-3845 and JZL184, it had no effect on benzodiazepine suppression of marble burying. This is in contrast to a recent report that that the anxiolytic effects of the benzodiazepine alprazolam were blocked by pretreatment with the CB1 antagonist AM251 in the light/dark box (Garcia-Gutierrez and Manzanares, 2010). This apparent discrepancy may be due to intrinsic differences between exploratory tests, such as the light/dark box, and marble burying, as described above.
