Figure 1: Compartimentalized expression of KARs in CA3 PCs. | Nature Communications

Figure 1: Compartimentalized expression of KARs in CA3 PCs.

From: Molecular determinants for the strictly compartmentalized expression of kainate receptors in CA3 pyramidal cells

Figure 1

(a) Schematic experimental setting. (b) Voltage-clamp recordings performed on CA3 PCs from acute and organotypic slices prepared from GluK2+/+ and GluK2−/− mice, in the presence of bicuculline (10 μM), D-AP5 (50 μM) and a low concentration of NBQX (150 nM), to limit polysynaptic activity. In all, average of 30 responses evoked at 3 Hz in the absence and in the presence of 25 μM LY303070, to isolate the mf-CA3 AMPAR-EPSCs and KAR-EPSCs, respectively. Insert, enlargements of isolated KAR-EPSCs. (c) Summary graphs for the relative amplitude of KAR-EPSCs versus AMPAR-EPSCs obtained in acute and organotypic slices prepared from GluK2+/+ and GluK2−/− mice. Mf KAR/AMPA ratio, acute GluK2+/+: n=6 cells; organotypic GluK2+/+: n=8 cells; acute GluK2−/−: n=5 cells; organotypic GluK2−/−: n=12 cells; A/C KAR/AMPA ratio: acute GluK2+/+: n=7 cells; organotypic GluK2+/+: n=7 cells; 27 mice. (d) Confocal image of a CA3 PC transfected with GFP illustrating glutamate uncaging spots (MNI glutamate, 500 μM) and corresponding evoked KAR currents. Purple arrowheads represent time of uncaging (405 nm, 2 ms). Average of five responses evoked at 0.1 Hz at each uncaging site. (e,f) Sample traces illustrating currents evoked by glutamate uncaging (bicuculline 10 μM, D-AP5 50 μM and NBQX 150 nM) in GluK2+/+ organotypic slices in different compartments of CA3 PCs, soma (S), thorny excrescences (TE), proximal shaft (PS) and distal dendrites (DDs). Summary graph of the average of net amplitude of evoked currents. Uncaging sites: S, n=3; TE, n=7; PS, n=3; DD, n=10, from 4 cells; 2 mice. (g,h) Sample traces illustrating KAR currents evoked by glutamate uncaging in GluK2+/+ organotypic slices in different compartments of CA3 PCs. Graph summarizing the average net amplitude of evoked KAR currents. Uncaging sites: S, n=7; TE, n=10; PS, n=5; DD, n=10, from 10 cells; 6 mice. (i,j) Sample traces illustrating the lack of KAR currents evoked by glutamate uncaging in GluK2−/− organotypic slices in different compartments of CA3 PCs. Graph summarizing the average net amplitude of the evoked currents. Uncaging sites: S, n=8; TE, n=18; PS, n=1; DD, n=8, from 5 cells; 4 mice.

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