Virus-mediated conditional KO of GABRA4 in the MD facilitates extinction. (A) Experiment scheme. (B) The GABRA4flx/flx mice injected with AAV-mCherry (filled circles, n = 6) or AAV-mCherry-Cre (empty circles, n = 11) into the MD showed no difference in fear conditioning. The Cre-virus injected group showed significantly lower freezing levels in the extinction learning and the recall test in comparison to the control virus injected group. (C and D) The two groups did not differ in the locomotion or anxiety. Data are means ± SEM.