The blood brain barrier (aka, BBB) can be a royal pain in the arse for pharmacologists and pharmaceutical companies. The ultimate goal of the neuro division of big pharm is to design drugs that can be taken orally and yet still cross the BBB with little issues. Billions of dollars can be gained or lost at the helm of the BBB. Well, new research in the recent issue of Journal of Neuroscience just introduced another conundrum for BBB permeability: sleep deprivation.

ResearchBlogging.orgThis BBB group in Louisiana investigated BBB permeability in lieu of chronic sleep deprivation on many levels. First, they found a reduction in glucose uptake by the brain, especially in regions that are in constant need of glucose like the cortex. Glucose uptake was measured by injecting radioactive glucose into the gut region and then measuring its transport up to the brain. A reduction in glucose uptake was complemented with a reduction in GLUT transporters which initiate the process of glucose being taken up by a tissue.



Glucose uptake compromised by sleep deprivation

The researchers also found an increase in COX-2, an enzyme involved in the initiation of pro-inflammation, with chronic sleep deprivation. This increase in pro-inflammation was accompanied by a decrease in forms of nitric oxide synthase which is responsible for vasodilation.

sleep deprivation interferes with vasodilation


What is most interesting is that all these pathologies disappeared with letting the mice get a day’s worth of recovery sleep. I’m a little skeptical about a day being enough to reverse a week’s worth of sleep loss even though the data reveals as such. But this is just the problem; we have no idea what the sleep deprivation protocol actually is and it is too difficult to interpret from the first figure! I’m starting to doubt that any of the reviewers are actually sleep researchers. It’d be acceptable for a middle-tier journal, but certainly not for a high-impact journal. One of the unwritten responsibilities of any reviewer is to ensure that the manuscript reads in such a way wherein the experiments can be replicated and the current hypothesis can either continue to be accepted or brought into question. The reviewers failed to do their jobs and the authors failed as scientists and now us readers of the flagship journal of the largest society of neuroscientists must scratch our heads and wonder what is so “unique” and ground-breaking about this protocol of chronic sleep deprivation that allows an animal and its body to recover in a single day.

He, J., Hsuchou, H., He, Y., Kastin, A., Wang, Y., & Pan, W. (2014). Sleep Restriction Impairs Blood-Brain Barrier Function Journal of Neuroscience, 34 (44), 14697-14706 DOI: 10.1523/JNEUROSCI.2111-14.2014