P2X4, P2X7 and P2Y12 immunoexpression in AMC in postnatal rat brain. By immunofluorescence labeling, P2X4 is colocalized with OX42 in the amoeboid microglial cells. Colocalization of OX42 and P2X4 in cells (arrows) is seen in the corpus callosum and subventricular zone (Aa-c, Scale bar = 100 μm). Immunopositive cells are round and have a typical morphology of amoeboid microglial cells (B/Ca-c. Scale bar = 20 μm). The amoeboid microglial cells exhibit a stronger P2X4 immunoreactivity compared with that of P2X7 and P2Y12 (D/Ea-c, Scale bar = 20 μm.).