Figure 1

Wedensky Ratio vs. Stimulation Frequency in Hexb+/- and Hexb-/- Mice. Wedensky ratios (see Materials and Methods) for Hexb+/- (○, dashed line) and Hexb-/- (●, solid line) mice were plotted against the stimulation frequency with linear regressions (n = 6–10) to analyze frequency-dependent conduction failure in the two mouse models. As evidenced by the decrease in the Wedensky ratio in both groups, conduction failure after a one second stimulus train increased in alternating CAP signals with increasing stimulation frequency. The slopes of the linear regressions were not different within 95% confidence levels indicating similar conduction failure behavior in the Hexb+/- and Hexb-/- mice. The first CAP signal recorded during a 1 second supramaximal stimulation at 600 sec^-1 is compared to the last four CAP signals in the train (scale conserved). Wedensky inhibition is observed. T _l , latency used for CNCV calculations; a, stimulus artifact; 1, amplitude of first CAP in stimulus train; L, S, CAP amplitudes after 1 sec of 600 Hz stimulation (1.67 msec between stimuli).