FIG. 2.

Morphological changes at the diaphragm neuromuscular junction (NMJ). Diaphragm neuromuscular junctions (NMJs) were assessed via labeling with rhodamine-α-bungarotoxin (red), SMI-312R (green) and SV2-s (green). All NMJs were completely intact in uninjured control rats, characterized by complete overlap of the presynaptic axon and presynaptic vesicles with postsynaptic acetylcholine receptors (Inset in A). Bar represents 50 μm in A. Following injury (A), the number of intact NMJs progressively decreased, reaching significance at 8 days post-injury (DPI) and 14 DPI (B). A significant portion of the abnormal junctions at 4, 8, and 14 DPI were categorized as partially denervated (D), although the presence of fully denervated NMJs was also observed at these time points (C). Signs of reinnervation, supported by the presence of multiply innervated NMJS (E) and thin axonal terminal sprouts (F), were detected as early as 4 DPI. Results are expressed as means±SEM. Statistical significance was assessed by analysis of variance (one-way ANOVA) and multiple comparisons post-hoc test (Bonferroni's method). *DPI versus uninjured (p<0.05); ***DPI versus uninjured (p<0.001). n=3 animals per group for all groups. Color image is available online at www.liebertpub.com/neu