To examine the role of CeA KOR and dynorphin in discriminative fear learning and anxiety-like behavior, we reduced Oprk1 and Pdyn expression in the CeA by injecting floxed Oprk1 and floxed Pdyn mice with and adeno-associated virus (AAV) containing an expression cassette for Cre-EGFP (AAV1-Cre-EGFP). This evidence concerns the gene OPRK1 and Anxiety.