Glia limitans

The Glia limitans is the outermost layer of proper nervous tissue of the brain, directly under the pia mater. They arise from astrocytes. They protect the brain tissue by providing a barrier of protection. The end feet of astrocytes cover the outside surface of brain tissue and make a physical barrier between the brain tissue and the connective coat on the outside. The glia limitans is better known as the blood-brain barrier.