Vivo: Afegostat (AT2101) increases GCase activity in brain, liver, and spleen. Afegostat (100 mg/kg) administrates orally for 4 months to Thy1-aSyn mice improved motor and nonmotor function, abolishes microglial inflammatory response in the substantia nigra, reduces α-synuclein immunoreactivity in nigral dopaminergic neurons, and reduces the number of small α-synuclein aggregates, while increasing the number of large α-synuclein aggregates.