Intracerebral Adenosine During Sleep Deprivation: A Meta-Analysis and New Experimental Data.
Level 5 - mechanism / opinion, no new human data
Preclinical animal microdialysis experiment combined with a meta-analysis of animal studies.
PubMed 30483348 · doi:10.5334/jcr.171
What was done
Researchers conducted a 64-hour microdialysis experiment measuring extracellular adenosine and adenosine monophosphate (AMP) concentrations in the medial prefrontal cortex of rats across five phases: 12-hour wash-out, baseline light phase, baseline dark phase, 12 hours of sleep deprivation via forced locomotion, and 12 hours of recovery. They also conducted a meta-analysis of published animal microdialysis experiments evaluating extracellular adenosine concentrations across brain regions during sleep deprivation.
What was found
In the rat prefrontal cortex experiment, median adenosine concentration was 0.36 nM (range: 0.004 to 27 nM) and showed no significant differences across the five conditions. Median AMP concentration was 0.10 nM (range: 0.001 to 7.56 nM), significantly increased during sleep deprivation (T = 47, p = 0.047), and normalized during recovery. In the meta-analysis, basal forebrain dialysate adenosine increased by 74.7% (95% CI: 54.1% to 95.3%) over baseline during sleep deprivation; cortical dialysate adenosine was reported by only 2 publications.
Why it matters
The findings suggest that sleep-deprivation-induced adenosine increases may be region-specific to the basal forebrain rather than brain-wide, with the cortex showing changes in AMP instead of free adenosine.
Limits
The study is restricted to animal models with an unstated sample size in the abstract. Sleep deprivation by forced locomotion introduces exercise and stress as confounders. Data on non-basal-forebrain regions remain extremely scarce.
Cited by
- supports Neuroplasticity occurs during sleep, and sleep reduces adenosine levels in the brain.