Effect of chloroquine intratechal injection on mechanical sensitivity. (A) Baseline mechanical thresholds were assessed in naïve mice for 2 consecutive days before the first injection. Chloroquine (300pmoles/3 μl) or vehicle were then injected intrathecally once daily. Two hours after treatment, mechanical sensitivity was measured by Von Frey’s test. The protocol was repeated for three consecutive days. (B) Localised spinal block of autophagy significantly reduced the threshold of mechanical sensitivity, in comparison to vehicle-treated mice. Data were expressed as mean ± SEM of the threshold of mechanical sensitivity. **P < 0.01. Vehicle n = 3, chloroquine (CQ) n = 6.