Representative sections of L4–L5 dorsal root ganglia (DRG) immunostained for CB2R from naive rats (A), from ipsilateral (D, F) and contralateral (E, G) DRG of chronic constriction injury (CCI) rats, and ipsilateral (H, J) and contralateral (I, K) DRG of sham-operated rats (sham). Control incubations with antibody after its absorption by protein (B) and with omission of primary antibody (C) displayed no immunostaining. Three days after CCI (D, E), both neurons (arrowheads) and satellite glial cells (SGCs; arrows) exhibited immunofluorescence for CB2R. Immunostaining was more pronounced ipsilaterally (D), and small- and medium-sized neurons displayed accentuated staining. Fourteen days from surgery (F, G), the immunostaining was much less. Sham-operated animals exhibited also higher immunostaining in contrast to that of naive rats, both ipsilaterally and contralaterally. Scale bars = 50 µm.