Fig. 11. Recovery from halothane anesthesia in the cat is delayed by administering an adenosine ^A1 receptor agonist into the medial pontine reticular formation (mPRF). The three functions plot the time course of recovery from halothane anesthesia during control dialysis (Ringer’s) and microdialysis delivery of two levels of the adenosine A¹ receptor agonist N⁶-p-sulfophenyladenosine (SPA). Simultaneous measures revealed that SPA also decreased acetylcholine (ACh) release (not shown). The study from which these data are taken support the interpretation that adenosine A¹ receptors in mPRF regions known to modulate sleep also contribute to generating halothane anesthesia. From Tanase  et al. ;  used with permission.