Fig. 7. Western blot analyses of NFATc1 and MEF2A in muscle fiber nuclear extracts. Innervated (SC) and non-innervated PM and MA muscle fibers were cultured in control medium or medium supplemented with 100 µM 2-APB. Muscle fiber nuclear extracts were prepared, electrophoresed and immunoblotted. NFATc1 and MEF2A were detected with respective primary antibodies and HRP-conjugated secondary antibodies. Inhibition of IP3R1 activity by 2-APB reduced NFAT abundance in nuclear extracts from all muscle fibers compared to the same cultures incubated in control medium. MEF2A nuclear abundance was not obviously affected by any of the other conditions tested.