L-glutamate concentration-response relationships of SmGluCl-1:SmGluCl-2.1 and SmGluCl-1:SmGluCl-3 hetero-oligomers in <i>Xenopus</i> oocytes.

<p>L-glutamate concentration-response relationships from oocytes injected with a 1∶1 ratio of <i>SmGluCl-1</i> cRNA and <i>SmGluCl-2.1</i> or <i>SmGluCl-3</i> cRNA. <b>A.</b> L-glutamate concentration-response relationships from oocytes injected with <i>SmGluCl-2.1</i> cRNA alone or injected with a 1∶1 ratio of <i>SmGluCl-1</i> and <i>SmGluCl-2.1</i>cRNAs. Co-injection of <i>SmGluCl-1</i> cRNA with <i>SmGluCl-2.1</i> cRNA decreased the response to glutamate compared to oocytes injected with <i>SmGluCl-2.1</i> cRNA alone (P<0.05, paired-T test), suggesting that SmGluCl-1 is a GluCl subunit and can form a heteromeric receptor with SmGluCl-2.1. <b>B.</b> L-glutamate concentration-response relationships from oocytes injected with <i>SmGluCl-3</i> cRNA alone or injected with a 1∶1 ratio of <i>SmGluCl-1</i> and <i>SmGluCl-3</i> cRNAs. Co-injection of <i>SmGluCl-1</i> and <i>SmGluCl-3</i> cRNAs did not alter the concentration-response relationship to glutamate compared to SmGluCl-3 homomeric receptors (P>0.05, paired-T test), suggesting that SmGluCl-1 cannot form a hetero-oligomer with SmGluCl-3 in <i>Xenopus</i> oocytes. All experiments were performed at a holding potential of ⁻80 mV. For the concentration-response curves, responses to each application were normalized by assigning 100% to the maximum amplitude of the response to L-glutamate. N = 3 (where N is batches of oocytes) and n = 8 (where n is the number of individual oocytes) for each data point. Values of EC₅₀ and the Hill coefficient are indicated as the mean ± SE. Error bars represent SD.