Functional exploration of metabotropic glycine receptors in cultured rat hippocampal slices
Kirika Takenaka, Masahiro MoriObjective
Metabotropic glycine receptors (mGlyRs) have been identified in the prefrontal cortex and nucleus accumbens, but their function in the hippocampus remains unreported. This study aimed to probe functional mGlyR signaling in the hippocampus.
Methods
We pharmacologically isolated conditions favoring mGlyR activation and performed gramicidin-perforated whole-cell recordings from CA3 pyramidal cells in rat organotypic hippocampal slice cultures. Intrinsic electrophysiological properties were compared before and after bath application of glycine. To assess G protein dependence, we examined responses after pretreatments with N-ethylmaleimide (NEM), a broad G protein blocker, and pertussis toxin (PTX), a Gi/o-selective inhibitor.
Results
Under control conditions, we observed changes indicating enhanced neuronal excitability, including an increase in the number of action potentials fired and a reduction in the amplitude of the medium after hyperpolarization. Moreover, in the presence of either NEM or PTX, the changes observed in the control group were abolished.
Conclusion
These results indicate that there are functional mGlyRs in the hippocampus and that they mediate their effects via Gi/o signaling.