Astrocyte alterations in α-synucleinopathies

Despite long being considered to be passive and supportive cells, in the last decades astrocytes have arisen as key regulators of neuronal excitability, synaptic transmission and plasticity. Since the discovery of the tripartite synapse, accumulating evidence suggests that astrocytes are involved in the pathogenesis of neurodegenerative diseases, including α-synucleinopathies. Here we will discuss recent evidence showing that astrocytes express endogenous α-synuclein and the implications of this protein in astrocyte cellular processes. Furthermore, we review how the expression of pathological forms of this protein in astrocytes leads to aberrant cytosolic Ca²⁺ activity in these cells and to alterations in gliotransmission and pathology progression.