The blood–brain barrier (BBB) is a large regulatory and exchange interface between the brain and peripheral circulation. We propose that changes of the BBB contribute to many pathophysiological processes in the brain of subjects with chronic sleep restriction (CSR). To achieve CSR that mimics a common pattern of human sleep loss, we quantified a new procedure of sleep disruption in mice by a week of consecutive sleep recording. We then tested the hypothesis that CSR compromises microvascular function. CSR not only diminished endothelial and inducible nitric oxide synthase, endothelin1, and glucose transporter expression in cerebral microvessels of the BBB, but it also decreased 2-deoxy-glucose uptake by the brain. The expression of several tight junction proteins also was decreased, whereas the level of cyclooxygenase-2 increased. This coincided with an increase of paracellular permeability of the BBB to the small tracers sodium fluorescein and biotin. CSR for 6 d was sufficient to impair BBB structure and function, although the increase of paracellular permeability returned to baseline after 24 h of recovery sleep. This merits attention not only in neuroscience research but also in public health policy and clinical practice.And, Weljie et al. find cross-species molecular markers of sleep debt:
Reduced sleep duration is a hallmark of modern-day society and is increasingly associated with medical conditions, such as diabetes, obesity, metabolic syndrome, and cardiovascular disease. Here we present data from a rat model and human clinical study of chronic sleep restriction, both revealing that two metabolites in blood, oxalic acid and diacylglycerol 36:3, are quantitatively depleted under sleep-restricted conditions and restored after recovery sleep. Our findings also reveal a significant overall shift in lipid metabolism, with higher levels of phospholipids in both species and evidence of a systemic oxidative environment. This work provides a potential link between the known pathologies of reduced sleep duration and metabolic dysfunction.