Astrocytes in the normal brain possess a stellate shape reflecting their non-migratory properties.
Alternatively, in neurodegenerative diseases or after injury, astrocytes become “reactive” in a process known
as astrocytosis or reactive gliosis, retract their processes, become polarized and acquire front-to-rear
asymmetry typical of migratory cells. On the other hand, neuronal migration is a common process during
embryonic development, but only few types of neurons can migrate and differentiate during adult life in the
central nervous system. Those that do migrate follow tracks made by glial cells and mainly give rise to
interneurons. In vitro, molecular mechanisms involved in adhesion of cells to and migration on extracellular
matrix proteins have been widely studied; however, signal transduction pathways explaining how particularly
neurons and astrocytes, mutually modulate adhesion and migration are less well known. In this review, we
describe and discuss how ligand/receptor interactions in astrocytes and neurons trigger signaling events
leading to actin and microtubule reorganization, changes in cell morphology, as well as cell adhesion and
migration. The biological significance these cell-cell interactions and signaling events might have in the brain
Astrocytes, cell adhesion, cell migration, neurons, signaling pathways.
Programa de Biología Celular y Molecular, Facultad de Medicina, Universidad de Chile, Santiago, Chile.