CAP from C57BL/6N sciatic nerves axotomized 0–48 hr in vivo and in vitro.A, A wave. B, C wave. In the first 6 hr after axotomy the CAP actually is increased. This is unlikely to be attributable to decreased temporal dispersion because the area of the waveform is increased. In both A and C waves, 80% of the CAP is lost between 24 and 36 hr. A similar time course for loss of the CAP is seen in vivo and in vitro. *p < 0.05.