Mechanical allodynia in different models of neuropathic pain. A severe and persistent hypersensitivity developed following SNL, SNI and CCI surgery. Calibrated von Frey filaments were used to determine the withdrawal threshold for punctate mechanical stimulation. Data were expressed as means of ± SEM of threshold of mechanical sensitivity. ***P < 0.001 for all three models in comparison to the sham group. SNL n = 6, SNI n = 8, CCI n = 5.