Fig. 3
Developing NMJs are not affected in VAChTHyp mice. Multiple axons (arrowheads) innervating the same postsynaptic site in P9 EDL muscles from control and VAChTHyp mice (a, b). Comparison of structural features revealed no discernable differences between genotypes. The size of AChR clusters (c), apposition between the presynaptic (green in a and b) and postsynaptic apparatus (red in a and b), d and the incidence of multiply innervating NMJs (e) were unchanged in VAChTHyp mice. Transcripts for the gamma and epsilon subunits of AChRs were also unchanged in developing (P9) EDL and TA muscles from VAChTHyp mice (f). Similar levels of myosin heavy chains type 2A, 2B, and 2X were also found in TA + EDL of developing (P9) control and VAChTHyp mice (g). While VAChT mRNA is elevated in the spinal cord of VAChThyp; Chat-cre;tdTom mice, it is unchanged in the spinal cord of 3-month-old Chat-cre;tdTom mice compared to wild-type mice (h). All mice used in this study were maintained on a C57BL/6 background. The following mice were used for NMJ analysis: Ctrl = Chat-cre;tdTom and VAChTHyp = VAChThyp;Chat-cre;tdTom. At least four mice were used for each genotype and per experiment. At least 25 NMJs per animal were examined. Scale bar = 10 μm. Error bar = Standard Error. P = 0.008