Figure 4.
Neuroterminal size (A–D), density (number of cells per μm2, E–H), and area fraction (% tissue represented by each terminal type, I–L), are shown for large, medium, small, and all terminals (mean ± SEM) from left to right. There were significant effects of age on the average size of the large terminals, and an age by treatment interaction (panel A, p<0.01; *p < 0.05 AV vs. AE, and AV vs. YV; ap < 0.05 YE vs. AE). A treatment effect and an age by treatment interaction were found for the % tissue, driven by E2 monkeys of both ages having a smaller tissue fraction compared to age-matched vehicle counterparts (panel I, bp < 0.05 YV vs. YE, and AV vs. AE). Abbreviation: Trt, Treatment.