Reduction in peripheral inflammation by changes in attention.
Peripheral inflammation in response to intra-articular injection of sodium urate was measured in birds showing pain-coping behaviour as well as in birds showing endogenous analgesia produced by changes in attention. Sixteen birds were injected with sodium urate into the left ankle joint. Eight birds were returned to their cages, and eight were placed in pairs into a novel pen. The birds placed into the novel pen showed significantly less pain coping behaviour in the 3-h period after injection than those birds returned to their cages. Both groups of birds showed elevated skin temperature over the inflamed joint, but in the birds in the novel pen this increase in temperature was significantly less than in the birds in cages. These results demonstrate that attentional shifts cannot only reduce the severe tonic pain of sodium urate arthritis, but also reduce peripheral inflammation.