Tonically active NMDA receptors--a signalling mechanism critical for interneuronal excitability in the CA1 stratum radiatum.

摘要: In contrast to tonic extrasynaptic γ-aminobutyric acid (GABA)A receptor-mediated signalling, the physiological significance of N-methyl-D-aspartate (NMDA) receptor (NMDAR)-mediated signalling remains uncertain. this study, reversible open-channel blockers NMDARs, memantine and phencyclidine (PCP) were used as tools examine NMDAR-mediated in rat hippocampal slices. Memantine concentrations up 10 μM had no effect on synaptically evoked responses pyramidal neurons or GABAergic interneurons. On other hand, reduced currents interneurons by approximately 50%. These contributed significantly excitability disynaptic inhibitory postsynaptic current cells about Moreover, memantine, but also PCP ≤ 1 μM, increased magnitude population spike, likely because disinhibition. The relatively higher impact was at least partly explained expression GluN2D-containing which not observed mature cells. results are consistent with idea that low doses readily NMDAR preferentially inhibit tonically active they suggest NMDARs contribute more prominently intrinsic excitation than It is proposed specific difference between can explain disinhibition caused Alzheimer's disease medication memantine.