Figure 1

Behavioural assessment at day 14 after monosodium iodoacetate ( n  = 27) or saline injection ( n  = 17). Monosodium iodoacetate (MIA injection) into the knee resulted in behavioural hypersensitivity, compared with the sham controls that received saline injections, as evidenced by the significant reduction in the paw withdrawal threshold to mechanical punctate stimulation (a), an increased paw withdrawal frequency to acetone application (b) and a decrease in the amount of weight borne on the hind limb ipsilateral to injection (c). *P < 0.05 compared with shams by Mann-Whitney U test. Values are means ± SEM.