FIG. 4.

Decreased expression with time in the neocortex and dentate gyrus. Shown is AAV2-HβH expression in the neocortex (A to C) and dentate gyrus (D to I). The number of in situ-hybridization-positive cells in the neocortex at 1 month (A) was substantially greater than that at 6 (B) and 12 (C) months p.i. Abundant expression was detected in the GCL at 1 month p.i. (D and E), followed by a continual decrease in expression at 6 (F and G) and 12 (H and I) months p.i. Viral vector expression was confined to the outer tier of the GCL in all time points. Scale bars: 500 μm (A to D, F, and H) and 50 μm (E, G, and I). Abbreviations: HL, hilus; IT, inner tier of the GCL; ML, molecular layer of the dentate gyrus; OT, outer tier of the GCL.