Fig. 5.
AMPA receptor subunit expression in physiologically characterized interneurons. A, An interneuron with outwardly rectifying kainate I–Vrelation that expressed all four AMPA receptor subunits by RT-PCR. Theinset shows an agarose gel separation of RT-PCR products from this cell. The open circles are fits of the Woodhull equation [KD(0)/[polyamine] = 6.28,z(1 − δ) = 1.01]. B, Neuron with inwardly rectifying kainate current [KD(0)/[polyamine] = 0.33,z(1 − δ) = 0.87] that expressed GluR1 and GluR3 mRNAs, but not GluR2 or GluR4. C, I–Vrelation from an interneuron showing strong inward rectification [KD(0)/[polyamine] = 0.14,z(1 − δ) = 0.92]; this neuron expressed GluR2, GluR3, and GluR4 in sufficient amounts to be detected by RT-PCR.D, Cumulative distributions of the affinity of internal blocker for 38 interneurons lacking GluR2 mRNA and 44 interneurons that expressed GluR2.