Figure 2.

Zn²⁺ mediated effects at NR1/NR3A receptors. (A) Zn²⁺ potentiation of glycine-induced currents at NR1/NR3A receptors. Normalized I–V plot of NR1/NR3A receptor currents activated by a saturating glycine concentration in the absence (triangle) and presence (square) of 50 μM Zn²⁺. Similar to MDL, also co-application of 50 μM Zn²⁺ with 100 μM glycine causes a linearization of NR1/NR3A receptor I–V relationship. (B) MDL potentiation of Zn²⁺-induced currents at NR1/NR3A receptors. Normalized I–V plot of NR1/NR3A receptor currents activated by a saturating Zn²⁺ concentration in the absence (triangle) and presence (square) of 200 nM MDL. Note that NR1/NR3A receptors display an outwardly rectifying I–V curve upon activation by Zn²⁺ irrespectively of whether MDL is present or not. (C) Normalized I–V plot of the LBD-mutant NR1^F466A/NR3A receptor currents activated by a saturating glycine concentration. Note that NR1^F466A/NR3A receptors display a linear I–V relation. (D) Rectification indices (R_i) of I–V relationships of wt and mutant NR1/NR3 receptors in the absence (black bars) and presence (gray bars) of potentiators.