GSK3B and infection: Three weeks after injection of AAV Gsk3 sgRNA/GFP or AAV GFP viruses, the infection area included PL, IL, and Cg cortexes, as shown by the expression of GFP in serial coronal sections of the mouse brain (Supplementary Fig. S1B).11 Thus, we investigated the ability of intersectional CRISPR-Cas9 to knock out GSK3β in D2 neurons of PL, IL, and Cg cortexes.