Chemokines increased [Ca2+]i levels in acutely isolated rat DRG cells following focal demyelination injury. The figure shows examples of responses of cells acutely isolated from rat DRGs ipsilateral to the nerve injury at various days after a focal demyelination injury. Under normal conditions, cells rarely respond to any chemokine but did respond to other stimuli such as high K or ATP (A). However, there was an increased responsiveness of the cells, the majority of which could be characterized as neurons, between post-operative days 14–28 (B and C, respectively). The frequency of the responses to chemokines returned to approximately the same level as control animals by post-operative day 35 (D). For all experiments, MCP-1 (M), IP-10 (I), RANTES (R), SDF1 (S) were applied at a concentration of 100 nM. Capsaicin (C), high K (K) and ATP (A) were applied at concentrations of 100 nM, 50 mM and 100 uM, respectively.