Roles of adenosine and its receptors in sleep-wake regulation.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing mechanistic and preclinical data without systematic methodology.
PubMed 25175972 · doi:10.1016/B978-0-12-801022-8.00014-3
What was done
This narrative review summarizes literature on the role of adenosine and its receptor subtypes (A1R, A2AR, A2BR, A3R) in sleep-wake regulation, focusing on adenosine brain levels, nucleotide breakdown, and pharmacological and molecular manipulations.
What was found
The abstract reports no numerical data or effect sizes. Extracellular adenosine increases in the cortex and basal forebrain during prolonged wakefulness and decreases during recovery sleep. Prostaglandin D2 elevates extracellular adenosine in the basal forebrain to promote sleep. Infusion of an A2AR agonist into the brain increases sleep, and caffeine-induced arousal is dependent on A2AR. A1R activation inhibits wake-promoting neurons to mediate sleep, but stimulates wakefulness when activated specifically in the lateral preoptic area.
Why it matters
The review synthesizes mechanistic evidence clarifying how adenosine acts as a homeostatic sleep regulator, highlighting the predominant sleep-inducing role of A2A receptors over site-dependent A1 receptor pathways.
Limits
This is a non-systematic narrative review providing no quantitative meta-analysis, sample sizes, or formal risk of bias assessments. The summarized findings rely heavily on preclinical animal and mechanistic models without direct human clinical data in the abstract.
Cited by
- supports Adenosine is cleared from the brain and body during sleep.