Partial Block by Riluzole of Muscle Sodium Channels in Myotubes from Amyotrophic Lateral Sclerosis Patients

Figure 2

Effect of riluzole on action potentials. Action potentials (a) elicited by a depolarizing current (top, 0.2 nA) and phase plot (b) of the same traces. In the presence of riluzole (grey traces), both peak depolarization and rate of rise were reduced, in spite of unchanged holding potential. Magnification of the inflection point (inset) discloses a depolarizing shift of the threshold of spike onset. The inflection point represents the threshold potential, the positive peak corresponds to the maximal depolarization rate, and the largest value on the horizontal axis is the spike peak value.

(a)

(b)