Dissecting the role of diazepam-sensitive γ-aminobutyric acid type A receptors in defensive behavioral reactivity to mild threat

► Lack of GABAA receptor α2 subunits results in elevated risk assessment to novelty. ► Lack of GABAA receptor α2 subunits gives rise to enhanced behavioral aversion. ► Drug activation of diazepam-sensitive α1-GABAA receptors reduces risk assessment. ► Diazepam-sensitive α2-GABAA receptors mediate the anti-aversive drug action.