Adenosine A1 Receptor Blockade Mimics Caffeine's Attenuation of Ethanol‐Induced Motor Incoordination

: The effects of co‐administration of caffeine and ethanol were assessed on the motor coordination of rats on the accelerating rotarod (accelerod). Ethanol (2.5 g/kg, orally) decreased motor performance on the accelerod. Co‐administration of caffeine (5 and 20 mg/kg, orally) dose‐dependently attenuated this ethanol‐induced deficit. Caffeine (20 mg/kg, orally) alone did not affect motor performance in the test. As caffeine is a non‐selective adenosine receptor antagonist the ability of adenosine A1 and A2A receptor blockade to attenuate ethanol‐induced motor incoordination was determined. Pre‐treatment with the adenosine A1 receptor antagonist DPCPX (5 mg/kg, intraperitoneally) attenuated ethanol (2.5 g/kg, orally)‐induced motor incoordination. By contrast, prior administration of the adenosine A2A selective antagonist SCH 58261 (10 mg/kg intraperitoneally) had no effect on the ethanol‐induced motor deficit. These data demonstrate that adenosine A1 receptor blockade mimics the inhibitory action of caffeine on ethanol‐induced motor incorordination, and may contribute to the ability of caffeine to offset the acute intoxicating actions of ethanol.