Figure 3. Representative photomicrographs of double immunostaining of the P2X₇ receptor and neuron-specific class III β-tubulin (TUJ1) in the normal retina and in the retina on days 1, 2, 3, and 7 after intraocular pressure (IOP) elevation. Immunoreactivity of the P2X₇ receptor was upregulated after IOP elevation, and the ganglion cell layer (GCL) cells were costained with anti-P2X₇ receptors and anti-TUJ1, especially in the retina on day 2. Upregulation of the P2X₇ receptor was suppressed by treatment with oxidized adenosine triphosphate (OxATP; 30 µM). Bar=100 µm.