Figure 1.

Oligodendrocytes express functional P2X receptors with high Ca²⁺permeability. A, ATP and BzATP, but not α,β-meATP, evoke inward, nondesensitizing currents, which are potentiated in the absence of Ca²⁺and Mg²⁺. ATP currents are blocked by PPADS (100 μm), a nonselective P2X antagonist. B, C, The P2X₇ antagonists oATP (1 mm) and BBG block ATP and BzATP currents. **p < 0.01. D, E, ATP and BzATP induce a rapid increase in [Ca²⁺]_i, an effect that is blocked by PPADS (50 μm) and in Ca²⁺-free incubation buffer, and greatly reduced by the P2X₇ antagonists oATP (1 mm) and BBG (100 nm). **p < 0.01 and ***p < 0.001.