Figure 3

CCL2 evokes a calcium-mediated activation of DRG neuronal and non-neuronal cells. A) Representative neuronal (n) and non-neuronal (g) in bright field (1) and at various times of the fluorescent calcium imaging recording (2-5) indicated in B. Concentration-dependent calcium rise evoked by CCL2 (black bar, 10, 50, 100 and 300 nM) in DRG neurons (left) and in non-neuronal cells (right). Traces are average calcium responses for all recorded cells. C) Calcium rise peak normalized to maximal neuronal response represented in a concentration-response curve (EC50 58.5 nM and 55.6 nM for neuronal and non-neuronal cells respectively). D) and E) Average calcium response curves evoked by 100 nM CCL2 (black bar) in DRG neurons in the presence of AZ889 0.1 nM (n = 9 cells), 1 nM (n = 7 cells), 10 nM (8 cells) and 100 nM (8 cells) normalized to control responses without AZ889 (IC50 1.5 nM). F) Calcium rise evoked by 100 nM CCL2 (black bar) in DRG neurons from CCI rats bathed in control conditions (grey) and in the absence of extracellular calcium (black). Peak amplitudes in control and in the absence of extracellular calcium are not significantly different (p > 0.05). G) Calcium rise evoked by 100 nM CCL2 (black bar) in DRG neurons from CCI rats bathed in control conditions (grey) and in the presence of U73122 (1 μM). U73122 produced a significant block of the calcium rise peak (p < 0.05).