Figure 4.

Intrathecal injection of Il-6 resulted in changes reminiscent of CCI-induced alterations in the rat dorsal spinal cord. Vehicle-injected rats showed almost undetectable pSTAT3-IR. In contrast, we observed bilateral accumulation of pSTAT3-IR (pSTAT3–Tyr705, in green) in the superficial layers of the dorsal spinal cord 15 min and 3 h after intrathecal acute injection of IL-6 (1 μg in 25 μl). At both time points, pSTAT3 labeling colocalized mainly with Iba1 microglial marker, showing some colocalization with the NeuN neuronal marker in only a very few cells and almost no colocalization with GFAP-labeled astrocytes. Scale bars, 200 μm.