Figure 6. Action potential characteristics of capsaicin‐sensitive double‐labelled and Fast Blue‐labelled afferent neurons.

Representative recordings of action potentials in double‐labelled, dichotomized afferent neurons from vehicle‐injected (A) and formalin‐injected rats (B), and Fast Blue‐labelled bladder afferent neurons from vehicle‐injected (C) and formalin‐injected rats (D). The thresholds for eliciting action potentials (panels a of A–D) in formalin‐injected rats was lower than those in vehicle‐injected control rats (Aa vs. Ba or Ca vs. Da). The number of action potentials during 800 ms membrane depolarization (panels b of A–D) in formalin‐injected rats was greater than that in control rats (Ab vs. Bb or Cb vs. Db). ^*Firing thresholds of action potentials.