Fig. 2.

Whole-cell patch-clamp recordings showed inward currents during exposure to ATP or to the P2X₇receptor-selective agonist BzATP. Representative recordings from single astrocytes are shown in A and B. Dose–response curves from averaged data (means ± SE) are plotted in C and D and expressed as the percentage of the 1 mm ATP-induced responses in normal divalent cation (standard) medium (n = 3–10 for each data point). Currents recorded in low Ca²⁺, low Mg²⁺ medium were significantly greater than in normal medium at all ATP and BzATP concentrations tested (p < 0.05). External solution, 100 mm NaCl; internal solution, 100 mm NMDG-Cl; holding potential, −40 mV.