To test whether Parkin deficiency alters the presynaptic release of two neurotransmitters with pivotal role in PD, i.e. dopamine and glutamate, we compared basic release parameters in wild-type versus parkin−/− mice a single layer of vertically superfused synaptosomes, where there is no interaction among the seeded nerve terminals and their neurotransmitters, thus allowing to study pure presynaptic release parameters [49]. Here, PRKN is linked to Parkinson disease.