Table 2.
Activity bursts were of similar duration but of significantly greater amplitude in gastrocnemius from 2‐month‐old HyperKPP mice than in 2‐month‐old wild type and 6‐month HyperKPP mice while reduction in EMG activity after an activity burst was predominantly observed in HyperKPP gastrocnemius
| Parameters | FVB | HyperKPP | |
|---|---|---|---|
| 2 months old | 2 months old | 6 months old | |
| Activity burst | |||
| Total number analyzed | 243 | 329 | 436 |
| Time fraction (%) | 0.43 ± 0.16 | 0.47 ± 0.08 | 0.53 ± 0.16 |
| Duration (msec) | 240 ± 23 | 260 ± 36 | 200 ± 24 |
| Amplitude (mV) | 1.32 ± 0.04 | 2.64 ± 0.46a | 1.70 ± 0.11b |
| Reduced EMG activity | |||
| Total number analyzed | 232 | 10 | |
| Time fraction (%) | 3.31 ± 2.04 | 0.11 ± 0.07 | |
| Duration (sec) | 2.85 ± 0.33 | 0.41 ± 0.26b | |
| Amplitude (μV) | 22.4 ± 9.9 | 14.2 ± 3.2 | |
The “total number analyzed” represents the number of all activity bursts/reduced EMG activity for a period of 1 h from all mice. Time fraction represents the total duration of all activity bursts/reduced EMG activity calculated as a percent of the total time analyzed. Measurement for the duration of an activity burst is as shown with arrows in Figure 7. Amplitudes of activity bursts/reduced EMG activity were calculated as the difference from the highest and lowest EMG peak. For each parameter, an average value was calculated for each mouse and those values were used to calculate the final mean. Data are expressed as mean ± SE of five mice. EMG, electromyography; ANOVA, analyses of variance; HyperKPP, hyperkalemic periodic paralysis.
Mean value for HyperKPP significantly different from mean value for FVB.
Mean value for 6 month HyperKPP significantly different from mean value of 2 month HyperKPP, ANOVA P < 0.05.