P2RY2 and Senile plaques: Accordingly to these opposite effects, it has been shown that P2Y2 haploinsufficiency increases senile plaques loading and enhances Aβ levels in the hippocampus of an amyloid mouse model [48], whereas the P2X7R pharmacological or genetic blockage reduces the number and size of amyloid plaques by reducing Aβ levels [21, 36].