Fig. 7.
Differential action of the ATP analogs ADP and α,β-mATP suggests expression of multiple subtypes of P2X receptors in RGCs with fast inactivating and slowly or noninactivatingIATP. A, B, D, E, Specimen recordings from four different RGCs with fast (A, D) and slow (B, E) decay kinetics ofIATP, respectively (Vh = −70 mV; CsCl-based pipette solution).IATP (top panels) and current responses to the respective analogs (bottom panels) elicited at the same agonist concentration (100 μm) are illustrated for comparison. C, F, Pooled data plotted as the ratio ofIADP/IATPandIα,β-mATP/IATPagainst peak amplitudes of IATP for 28 and 10 different RGCs, respectively. Note the large scattering of the data points.