Table 2. Plateau potential parameters in 9-AC treated wild-type and ncDHPR muscle.
| Pre-myotonia vm (mV) | Initial plateau vm (mV) | PP repol slope (mV/s) | Final PP vm (mV) | Max repol rate (mV/s) | Post PP vm (mV) | Duration of PP (s) | |
|---|---|---|---|---|---|---|---|
| Wild type | −79.3 ± 0.9 (−79.5) |
−36.0 ± 1.6 (−36.0) |
−3.3 ± 0.7 (−3.1) |
−48.1 ± 1.2 (−48.5) |
−125 ± 6 (125) |
−79.5 ± 0.4 (−79.7) |
3.9 ± 0.7 (3.8) |
| ncDHPR | −78.9 ± 0.6 (−79.0) |
−37.2 ± 0.8 (−37.1) |
−5.4 ± 0.6* (−5.3) |
−49.2 ± 1.1 (−49.7) |
−134 ± 10 (138) |
−79 ± 0.8 (−79.3) |
2.4 ± 0.3* (2.3) |
Shown are the mean value and the standard deviation for parameters of plateau potentials in 9-AC treated wild-type and ncDHPR fibers. Below the mean value in parentheses is the median value. n = 41 fibers from four wild-type mice and n = 47 fibers from three ncDHPR mice. Vm is membrane potential, and repol is repolarization. Pre-myotonia Vm is the resting membrane potential prior to stimulation. Initial PP Vm is the membrane potential at the beginning of the plateau potential. Final PP Vm is the membrane potential prior to the sudden repolarization terminating the plateau potential. Max repol rate is the maximum rate of repolarization during the sudden repolarization. Post PP Vm is the membrane potential following termination of the plateau potential. * indicates p=0.01 for both significant differences (t-test).