Expression of CCR2 mRNA and protein immunoreactivity in rat lumbar DRG ipsilateral to focal nerve demyelination. A) Lumbar DRG removed from vehicle-treated animals at POD7 did not exhibit CCR2 mRNA expression (n = 5). B) Many lumbar DRG neurons in vehicle-treated rats sensory neurons were positive for isolectin IB4, a neuronal phenotype that distinguishes some C-fiber nociceptors (green cells). There was no evidence of CCR2 protein expression in sham animals (n = 5). C) Lumbar DRG neurons from nerve-injured rats on POD7 exhibited CCR2 mRNA transcripts in some small and medium diameter neurons (black arrows). Open black arrowhead indicates a neuron without CCR2 mRNA transcripts (n = 4). D) Lumbar DRG neurons from a rat subjected to focal nerve demyelination exhibited few CCR2 immunopositive (white arrows) sensory neurons (n = 4). E) Many lumbar DRG neurons on POD14 exhibited CCR2 mRNA transcripts (black arrows). Open arrowhead indicates non-labeled neuron. F) CCR2 immunoreactivity was present in an increased number of neurons at POD14 (white arrows; n = 5). Scale bar is; 30 μm (A, C), 50 μm (B, D, F), and 100 μm (E).