Anxiogenic effects of the intraamygdala injection of flumazenil, a benzodiazepine receptor antagonist.

The effects of bilateral intraamygdala microinjection of flumazenil, a benzodiazepine receptor (BZD-R) antagonist, on the exploratory activity in an elevated plus maze were examined in chronically implanted rats. This compound induced a significant decrease in the time spent in the open arms, which is consistent with an anxiogenic action. No effect was observed after intrastriatal injections of flumazenil. Naive rats exposed to the elevated plus maze showed a rapid and selective decline in the content of BZD-like molecules in amygdala (-68%) but not in striatum and hippocampus. These data suggest that the anxiogenic effects of the intraamygdala injection of flumazenil is probably due to the blockade of BZD-like molecules released during the performance.