Opposite changes in adenosine A1 and A2A receptor mRNA in the rat following sleep deprivation

Extracellular levels of adenosine increase in basal forebrain following prolonged wakefulness. Moreover, perfusion of adenosine into basal forebrain increases sleep. In this study we have examined the adenosine receptor subtypes, A(1) and A(2A), for changes in the levels of mRNA using RT-PCR and in situ hybridization and the receptor ligand binding efficiency using autoradiography following 3 and 6 h of sleep deprivation. We observed that A(1) receptor mRNA levels increased in basal forebrain with no changes in other forebrain areas examined. A(1) receptor binding was not affected. A(2A) receptor mRNA and ligand binding were undetectable in basal forebrain. However, in the olfactory tubercle, A(2A) mRNA and receptor binding decreased significantly. Based on the significant increase in the A(1) but not in A(2A) receptor, we hypothesize that the effects of sleep deprivation-induced increased adenosine are mediated by A(1) receptor in basal forebrain of rats. NeuroReport 12:1577-1580 (C) 2001 Lippincott Williams & Wilkins.