The alterations in the levels of mGluR5 in selected brain regions display increased α-syn accumulation in patients with DLB or PD, as well as in α-syn transgenic mice; thus, the vulnerability of hippocampal neurons to α-syn and Aβ might be mediated by mGluR5 [18, 19]. The gene discussed is GRM5; the disease is Lewy body dementia.