Alpha-synuclein belongs to a family of vertebrate proteins, encoded by three different genes: alpha, ss, and gamma. The protein has become of interest to the neuroscience community in the last few years after the discovery that a mutation in the alpha-synuclein gene is associated with familial autosomal-dominant early-onset forms of Parkinson Disease. However, it is not yet clear how the protein is involved in the disease. Several studies have suggested that alpha-synuclein plays a role in neurotransmitter release and synaptic plasticity. This hypothesis might help elucidate how alpha-synuclein malfunctioning contributes to the development of a series of disorders known as synucleinopathies.