Figure 2. An example of the conduction velocity-slowing (latency increasing) effects of stepwise increases in bupivacaine concentration in two dorsal root axons. The deflection at the furthest left is the stimulus artifact in six superimposed traces. The responses of two axons can be seen (data were not collected from the low spike amplitude axon because of its unfavorable signal-to-noise ratio). As the bupivacaine concentration was increased from 0 micro Meter in five steps to 30.6 micro Meter (10.6, 16.0, 23.2, 26.4, and 30.6 micro Meter), the conduction latency (time between stimulus artifact and action potential) progressively increased.