Activation threshold of dorsal root in control and OA animals.

<p>A 0.04 ms rectangular pulse stimulus was delivered to dorsal roots at 4 weeks after surgery in control and in OA animals. (A) Shows the comparison of minimal electrical current sufficient to evoke an AP between OA (<i>N</i> = 25) and control muscle afferent neurones (<i>N</i> = 21). The Mann-Whitney <i>U</i>-test was used. (B) Shows the number of neurones evoked at various current strengths to the dorsal root in both control and OA muscle afferent neurones.