The astrocytes are specialized brain cells arranged in a specific geometric pattern. The location of astrocytes forming icosahedrons adds to their functional importance. By connecting the capillaries with the neurons they transport nutrients and energy that help the neurons function properly. Without the astrocytes the neuron would die. The astrocytes functionally create the blood brain barrier as they regulate the interstitial fluid, part of the glyphatic system. The interstitial fluid works to provide nutrition and allows the brain to clear waste materials in a manner that increases with proper sleep. There exists a general flow of interstitial fluid through the brain tissue.