Density of CREB and p-CREB immunoreactivity after intrathecal treatment with the adenylate cyclase inhibitor, SQ 22536, or saline. A, CREB remains unchanged after spinal inhibition of adenylate cyclase with SQ22536. B, The increase in p-CREB is prevented after spinal inhibition of adenylate cyclase with SQ22536 compared with the intrathecal saline control. I–II, Laminas I and II; III–VI, laminas III–VI. Data are presented as the average with the SEM. *Significantly different from saline control; p ≤ 0.05.