Neuron-Astroglial Interactions in Cell Fate Commitment in the Central Nervous System

Until about 100 years ago, astroglial cells were regarded solely as passive components of the nervous system. During the past few years, however, increasing knowledge of these cells has completely changed this scenario: rather than mere inert “brain glue”, astroglial cells are now considered active partners of neurons, and they seem to be much more actively involved in brain function than was formerly thought. Recent evidence shows that astroglia, in addition to their previously known roles in neurotransmitter clearance, ion buffering, and neuronal trophic support, are also involved in other functions, such as synapse development and neurogenesis. In this review, we will focus on the role of astroglial cells, mainly radial glia and astrocytes, in several events of nervous system development such as cell fate commitment, neuronal and astrocyte maturation, and synapse formation. We will argue that the functional architecture of the brain depends on an intimate neuron-glia partnership. Finally, we will briefly discuss the emerging view of astrocytes as essential actors in neurodegenerative diseases and neurological disorders, and how a better understanding of glial development might open new avenues to develop therapeutic approaches to these pathologies.