Transgenic (Tg) neuronal rescue of FIG4 expression largely restores plt myofiber size. (A) Hematoxylin and eosin–stained sections of gastrocnemius muscle from wild-type (WT) and Fig4−/−/NSE-FIG4 (that is, plt with transgenic expression of Fig4 driven by the neuron-specific enolase (NSE) promoter). The plt muscle is essentially indistinguishable from WT, with the exception of mild reduction in fiber size. (B) Quantification of myofiber size from quadriceps muscles of 8-month-old Fig4−/−/NSE-FIG4 and WT animals. There was a small but significant reduction in total fiber area in transgenically rescued plt muscle: 2,799 μm2 ± 165 for WT vs 2,322 μm2 ± 121 for plt (n = 60, P = 0.02). (C) Transmission electron photomicrographs from tibialis anterior muscle. Normal triads and mitochondria were present in both WT and plt/Tg-NSE-Fig4 animals.