Fig. 4. Inhibition of Ca2+-induced Ca2+release by dantrolene. ( A ) Control small dorsal root ganglion (DRG) neurons show decreased area of depolarization-induced (K+, 50 mm) transients in the presence of dantrolene (10 μm), whereas the transient in neurons isolated from the fifth lumbar (L5) DRG after spinal nerve ligation (SNL) is not diminished by dantrolene. ( B ) Summary data shows that SNL L5 neurons lack inhibition of Ca2+-induced Ca2+release by dantrolene, compared to control and SNL L4 neurons. One-way ANOVA with Bonferroni post hoc testing, numbers in bars indicate n for number of neurons; brackets indicate significant difference ( P < 0.05); bars indicate mean ± SD.