Extracellular Matrix: Functions in the Nervous System

An astonishing number of extracellular matrix glycoproteins are expressed in dynamic patterns in the developing and adult nervous system. Neural stem cells, neurons, and glia express receptors that mediate interactions with specific extracellular matrix molecules. Functional studies in vitro and genetic studies in mice have provided evidence that the extracellular matrix affects virtually all aspects of nervous system development and function. Here we will summarize recent findings that have shed light on the specific functions of defined extracellular matrix molecules on such diverse processes as neural stem cell differentiation, neuronal migration, the formation of axonal tracts, and the maturation and function of synapses in the peripheral and central nervous system. E xtracellular matrix (ECM) glycoproteins are widely expressed in the developing and adult nervous system. Tremendous progress has been made in defining the roles of specific ECM components in controlling the behavior of neurons and glia Here, we will provide an overview of ECM functions in the nervous system, emphasizing recent findings that have shed light on the mechanisms by which ECM glycoproteins regulate such diverse processes as neural stem cell (NSC) behavior, neuronal migration, formation of axonal processes and their myelin sheets, and synapse formation and function.