Coadministration of the adenosine A₁ receptor agonist N⁶-sulfophenyl adenosine (SPA) and antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) to the pontine reticular formation (A) blocked the SPA-induced decrease in acetylcholine (ACh) release, and (B) increased time to resumption of righting after isoflurane anesthesia. Data for SPA (solid bars) are from figure 6A and B (0.1 mm SPA). Asterisks indicate a significant (P < 0.05) difference from SPA.