Inhibition of the cAMP/PKA/CREB Pathway Contributes to the Analgesic Effects of Electroacupuncture in the Anterior Cingulate Cortex in a Rat Pain Memory Model

Figure 1

Flow chart of the procession of a pain memory model and intervening measures. The pain memory model was induced by two injections of carrageenan. The first inflammatory reaction was induced with carrageenan injection in the left hind paw at day 0. The paw withdrawal thresholds (PWTs) at days −1, 0, 1, 3, and 5 were recorded and that the one at day −1 was regarded as the baseline value. The EA/indo interventions were administered at 5 h, 1–5 d after the first carrageenan injection. The second inflammatory reaction was induced by injection in the right hind paw at day 14. The PWTs at day 13 through 17 were recorded and the one at day 13 was regarded as the new baseline value. The PWTs of the left (uninjected in the second injection of carrageenan) hind paw on day 15 through 17 manifested the memory of pain.