AAVs with synthetic CRMs can target PV+ neurons in the brain.A, the schematics of the PV synthetic CRMs. B–D, representative images of infected brain regions and quantification of the labeling specificity and efficiency of AAV-pAllPV-GFP (B), AAV-pPV-GFP (C), and AAV-pPV-gCre (D). For each panel, top, experimental design. Middle, representative images showing AAV labeled cells (GFP or tdTomato signals) and PV antibody staining. Scale bar: 100 μm. Bottom, quantification of the labeling specificity and efficiency. Mean ± SD. N ≥ 4 mice. AAV, adeno-associated virus; CRM, cis-regulatory module; PV, parvalbumin.