Chronic sleep restriction disrupts interendothelial junctions in the hippocampus and increases blood –brain barrier permeability

In this study we characterised the ultrastructure of interendothelial junctions in the hippocampus, the expression of tight junction proteins, and quantified blood–brain barrier permeability to fluorescein‐sodium after chronic sleep restriction. Male Wistar rats were sleep restricted using the modified multiple platform method during 10 days, with a daily schedule of 20‐h sleep deprivation plus 4‐h sleep recovery at their home‐cages. At the 10th day hippocampal samples were obtained immediately at the end of the 20‐h sleep deprivation period, and after 40 and 120 min of sleep recovery. Samples were processed for transmission electron microscopy and western blot. Chronic sleep restriction increased blood–brain barrier permeability to fluorescein‐sodium, and decreased interendothelial junction complexity by increasing the frequency of less mature end‐to‐end and simply overlap junctions, even after sleep recovery, as compared to intact controls. Chronic sleep loss also induced the formation of clefts between narrow zones of adjacent endothelial cell membranes in the hippocampus. The expression of claudin‐5 and actin decreased after chronic sleep loss as compared to intact animals. Therefore, it seems that chronic sleep loss disrupts interendothelial junctions that leads to blood–brain barrier hyperpermeability in the hippocampus. Lay description Sleep function has remained elusive since the past century. Previous reports have shown that sleep is fundamen...
Source: Journal of Microscopy - Category: Laboratory Medicine Authors: Tags: Original Article Source Type: research