Fig. 1. Effect of spinal transection on isoflurane mean alveolar concentration (MAC). Mean MAC values obtained from tail clamp (  open circles ) and hind paw (HP) clamp (  filled triangles ) and forepaw (FP) electrical stimulation (  filled squares ) before (BL) and up to 28 days after spinal transection. Mean MAC values for both tail and hind paw clamp decreased significantly after transection and remained significantly reduced during the entire 28-day period, although there were significant increases in MAC values at 14 and 28 days after transection (D14 and D28). Mean MAC values obtained from forepaw stimulation remained unchanged after transection. * Significantly decreased compared with pretransection values. + Significantly decreased from pretransection values, but significantly increased from 3-day values.  Error bars = mean ± SD.