Figure 2

Activity dependent inactivation of NFATc1. Representative confocal images of intercostal (A-C; ItC), soleus (D-F; Sol) and flexor digitorum brevis (G-I; FDB) muscle fibers expressing NFATc1-GFP. The atypical response of intercostal fibers (A-C) compared to Soleus (D-F) and FDB (G-I) after stimulation is quantified by comparing baseline (J, black line) to the change in N/C ratio after 90 minutes of stimulation (J, red line). Although there is substantial heterogeneity in the responses of individual nuclei (K), the overall behavior of nuclei in fibers from intercostal muscles is significantly different from either FDB or soleus (L). Panels M, N, O show representative confocal images of ItC, Sol and FDB fibers expressing GFP. n = 40, 37, 38 nuclei from 15, 14, 25 fibers isolated from 4, 4, 3 animals for ItC, Sol and FDB respectively. Error bars show SEM.