Objective: The myelin-associated inhibitors play a very important role in preventing the regeneration of the adult central nervous system. Among these inhibitors it is Nogo-A, a recently cloned protein expressed by oligodendrocytes. However, after its discovery as a myelin-associated protein, there has been described new functions for Nogo-A far from its role in the oligodendrocytes myelin.

Development: After an introduction to the molecular changes that occur after a central nervous system (CNS) injury we focus in the figure of Nogo-A and its family of proteins. Finally, we make a revision of the different functions that have been described to date for Nogo-A, from the development of the CNS to the inhibition of axonal regeneration in the adult, highlighting the therapeutic potential of the selective blockade of Nogo-A.

Conclusions: Although Nogo-A was discovered in the context of axonal growth inhibition, in which it is indeed playing a determining role, Nogo-A has turned out to be also a neuronal protein involved in diverse processes that go from axonal fasciculation to apoptosis. As we deepened in our knowledge about the molecular mechanisms that organize the complex functioning of the CNS, it is clearer that the proteins implicated in fasciculation and axonal guidance during development also play equally important roles in mechanisms like the axonal inhibition or the regulation of the synaptic plasticity in the adult CNS.