Figure 2. Ergometry.

Mice were subjected to exercise tests on a treadmill before and 40^th week after plasmid immunization. The pre-immunization mice (eight weeks old) are represented by gray bars (N = 10). Non-immunized mice (N = 5, dashed bars) with the same age as immunized mice (57 weeks old) were submitted to the same test. Mice immunized with pcDNA3-hM2 are represented by black bars (N = 5) and with pcDNA3 plasmid by white bars (N = 5). The letter a indicates a comparison between the WT pcDNA3 and WT M₂AChR groups, while letter b indicates a comparison between the P2×7^−/− pcDNA3 and P2×7^−/− M₂AChR groups. In these cases p < 0.05 was considered statistically significant. **(p < 0.01) and ***(p < 0.001) indicate comparison of the results obtained for immunized mice groups at 40 weeks with those obtained at the pre-test (grey bar).