Tau proteins are important to a properly functioning nervous system. They interact with tubulin (a spherical protein, which is the building block of microtubules and important to the cell’s structure). When functioning properly, tau proteins interact with tubulin and strengthen the neural tubes in the axon (a process that extends from the neuron, or nerve cell, to carry a signal). The neural tubes are like highways that allow the nervous signal to travel down the axon.
There are neurodegenerative diseases, like Alzheimer’s disease, that are known a tauopathies. This means that there has been disruption in the tau protein, creating instability in the neural tubes. This disrupts the signals in the central nervous system, leading to symptoms like dementia.