Raw data for Selective reduction of Ca2+ entry through the human NMDA receptor - a quantitative study by simultaneous Ca2+ and Na+ imaging

Excessive Ca2+ influx through N-methyl-D-aspartate type glutamate receptors (NMDAR) is associated with excitotoxicity and neuronal death. Thus, a reduction of NMDA-mediated Ca2+ entry could represent a valid neuroprotective strategy. We developed a new two-fluorophore approach to efficiently assess the Ca2+ permeability of ligand-gated ion channels, including NMDARs, in different conditions. This technique was able to discriminate differential Ca2+ permeation through different receptor-channels, and through the same channel in different conditions. With this method we confirmed that EU1794-4, a negative allosteric modulator of NMDARs, decreased their Ca2+ permeability. Furthermore, we measured for the first time the fractional Ca2+ current (Pf, i.e. the percentage of the total current carried by Ca2+ ions) of human NMDARs in the presence of EU1794-4, exhibiting a 40 % reduction in comparison of control conditions. EU1794-4 was also able to reduce NMDA-mediated Ca2+ entry in human neurons derived from induced pluripotent stem cells. This last effect was stronger in the absence of extracellular Mg2+, but still significant in its presence, supporting the hypothesis to use NMDA-selective allosteric modulators to lower Ca2+ influx in human neurons, to prevent Ca2+-dependent excitotoxicity and consequent neurodegeneration. To use data please refer to each figure legend in the associated paper. Data are organized following the figure order (1 figure, 1 directory), with subdirectory including each distinct experimental condition. Data used as control and used in multiple figures are only reported in the directory related to the first figure in which they are displayed. Files including fluorescence microscopy data (concerning all figures) are derived and must be visualized using the Sofware MetaPhluor (Molecular Devices). Files including electrophysiological data (patch-clamp; Fig.5 only) can be visualized by using ClampFit (Molecular Devices). For any further information please contact Prof. Sergio Fucile ([e-mail])