We assessed hyperalgesia, histopathological changes, immunoreactive (-ir) neurons for calcitonin gene-related peptide and activating transcription factor 3 in DRG, and immunoreactive neurons for ionized-calcium-binding adaptor molecule 1 (Iba1) in the dorsal horn of the spinal cord.
Results revealed that increased hyperalgesia was concurrent with an increment of Iba1 (P < 0.001), TNF-α (P < 0.001), PTEN (P < 0.01), cleaved caspase-3 (P < 0.001), and a decrement of P.Akt (P < 0.01) during the acute phase of CFA-induced inflammation, while, at the same time as decreasing hyperalgesia during the chronic phase of study, Iba1 and TNF-α expression significantly decreased and PTEN, cleaved caspase-3, and P.Akt restored to baseline on day 0.
Behavioral tests revealed allodynia, ongoing pain, and increased expression of c-fos, GFAP, and Iba1, as well as the absence of hyperalgesia in Burn7s.
Immunohistochemical analysis showed that spinal microglia were activated and that the P2X4R level was increased and colocalized with ionized calcium-binding adapter molecule 1 in NTW-induced hyperalgesia.