Caffeine withdrawal affects central adenosine receptors but not benzodiazepine receptors.

The effects of chronic caffeine administration on both adenosine and benzodiazepine receptors were studied in mouse brain membranes. Animals were fed on a diet enriched with caffeine (600 mg/kg diet) for 15 days and sacrificed 2, 4, 8 and 15 days after withdrawal. Compared with controls fed on a regular diet, animals receiving a caffeine-enriched diet showed an increase in the number of brain adenosine receptors labeled with [3H]-DPX in both the cerebellum and forebrain regions. This up-regulation was still significant 15 days after withdrawal in the cerebellum but not in the forebrain, where the number of adenosine receptors returned to control levels within 8 days following withdrawal. Benzodiazepine receptors labeled by [3H]-B-CCE were not influenced by chronic caffeine diet or withdrawal.