LRRK2 and late-onset Parkinson disease: PD mutations in VPS35, a part of the retromer complex, also serve to potentiate the actions of LRRK2 kinase activity (Mir et al., 2018) and impact AMPA receptor recycling in cortical and hippocampal neurons and hippocampal LTP (Munsie et al., 2015; Temkin et al., 2017).