Gene delivery by stereotaxis. (A) Cross-section of mouse brain, injected in one hemisphere with AAV2/1-CAG-GFP-WPRE, reveals widespread green fluorescence in the striatum. (B) Similar distributions are seen when injecting the GFP construct in both hemispheres (as for the behavioral assay). The zinc finger construct AAV2/1–CAG–ZF11xHunt–Kox-1–WPRE was injected at an identical titer in one or both hemispheres as described. (C) Schematic drawings show the maximum and minimum volume covered by GFP expression in mice injected in both hemispheres (n = 4). AP levels are as in the Paxinos and Watson atlas of the mouse brain (54). aca, anterior comissure; Acb, nucleus accumbens; AP, anteroposterior; lo, olfactory tract; St, striatum; Tu, olfactory tubercle. (Magnification, A, B: 2.5× objective; Scale bar, C: 1 mm.)