Effects of chronic sleep restriction on blood vessel density in the prefrontal cortex and hippocampus in rats

Abstract

Increased blood vessel density could increase the efficiency of the glymphatic system which removes waste from the brain. This study tested the hypothesis that chronic sleep restriction (CSR) increases blood vessel density in brain regions, such as the prefrontal cortex, where wake and sleep deprivation are associated with higher levels of neuronal activity compared to sleep, but not in those regions where neuronal activity does not increase during wake, such as the hippocampus. In the prefrontal cortex, a small increase in newly grown blood vessels was observed after four days of CSR while total blood vessel density did not increase. No increase in newly grown vessels occurred after 4 four-day cycles of CSR. In the hippocampus, there was no effect of CSR on blood vessel density. Based on these results, it is unlikely that CSR under the current condition has a major effect on the efficiency of the glymphatic system.