Focal deletion of Cav1.2 in the dorsal hippocampus induces a deficit in extinction of cocaine CPP. A, D, Representative images of green fluorescent protein (GFP)-positive cells and representations of coronal sections showing spread of AAV expression, as indicated by green symbol labeling, resulting from AAV bilaterally microinjected into dorsal hippocampus (A) or ventral hippocampus (D) of cacna1cfl/fl mice. B, Deletion of Cav1.2 in the dorsal hippocampus had no effect on acquisition of cocaine CPP, but attenuated extinction significantly compared with mice injected with AAV-GFP. C, Deletion of Cav1.2 in the dorsal hippocampus had no effect on maintenance of cocaine CPP when tested 4 d after the acquisition test. E, Deletion of Cav1.2 in the ventral hippocampus had no effect on acquisition or extinction of cocaine CPP. F, Deletion of Cav1.2 in the ventral hippocampus had no effect on maintenance of cocaine CPP. ***p < 0.001 compared with baseline test; #p < 0.05, ###p < 0.001 compared with acquisition test. Data are presented as mean ± SEM.