Fig. 2.

Calcium transients are ablated in fibers overexpressing Foxo1-GFP. A: control fibers (n = 24, N = 4) exhibit calcium transients in response to either a single 25-V field stimulation pulse (1-ms duration) or a 180-ms, 100-Hz train of such stimuli. B: fibers expressing Foxo1-GFP (n = 35, N = 5) show decreased calcium transients in response to the same pattern of electrical stimulation. C: fibers expressing GFP (n = 40, N = 4) alone respond to electrical stimulation with a calcium transient in a manner consistent with typical healthy FDB fibers. N indicates number of mice per condition, and n indicates number of fibers tested. D: average change in the indo-1 ratios of fibers in response to electrical simulation is dramatically decreased in fibers expressing Foxo1-GFP compared with control and GFP fibers. *P < 0.05, compared with control and GFP fibers. E: indo-1 resting ratios are not statistically different in fibers expressing Foxo1-GFP and fibers expressing GFP alone compared with control fibers. F: distribution of Δindo-1 amplitude in response to a single stimulus. The majority of Foxo1-GFP fibers have a range of no response to decreased intensity, whereas control and GFP fibers have varying degrees of strength. G: percentage of Foxo1-GFP fibers that exhibited a calcium transient, as defined by peak Δindo-1 ratio >0.1 in response to electrical stimulation is significantly lower than that of control fibers and GFP fibers.