Confocal images of mixed hippocampal cultures immunostained with anti-P2Y receptors (green) and neuronal markers anti-MAP-2 (red). Both P2Y2 and P2Y4 receptor immunostaining is not seen in neuronal cell bodies or processes but astrocytes are profusely stained. In merged images, some pixels appear yellow because of the neurons (red) overlying the brightly stained (green) astrocytes.