April 24, 2017Basic Biology
The blood-brain barrier is the layer of cells that line the blood vessels of the brain. The inner cell layer that lines vessels, known as the endothelium, is present in all the blood vessels of the body. Within the blood vessels of the brain, endothelial cells and other adjacent cells form a tight barrier that helps to prevent toxins and microbes from entering the brain. Although their function is not completely understood, a special population of cells covering the blood vessels on the brain's surface is thought to contribute to the organ's protection. The cells act as sentries, engulfing toxins, cellular wastes and microbes and then encasing them in sphere-like structures called vesicles. These sentry cells are called fluorescent granular perithelial cells (FGPs) because the vesicles they contain give off a yellow glow in the presence of light. FGPs are thought to be important in a variety of human brain disorders and conditions. These cells appear to be a major entry point for HIV infection of the brain. Age-related decline in cognitive function is associated with a decline in the scavenging function of FGPs. According to the authors, learning more about how FGPs function may lead to a greater understanding of dementia and other conditions.