Contribution of metabotropic glutamate receptors to the depression of excitatory postsynaptic potentials during hypoxia

WE tested the hypothesis that activation of metabotropic glutamate receptors (mGluR) might contribute to the depression of excitatory postsynaptic potentials during hypoxia. The experiments were performed on hippocampal slices taken from young (12-14 days old) Wistar rats. The depression induced by hypoxia (14 min) was not modified in the presence of either the non-selective mGluR antagonist (which blocks mainly group I and II mGluR), MCPG (500 mu M) or the selective group III mGluR antagonist, MPPG (500 mu M). However, in experiments performed in the presence of the selective adenosine A(1) receptor antagonist, DPCPX (50 nM), part of the hypoxia-induced depression could be prevented by MPPG (500 mu M). Activation of group III mGluR may contribute to the hypoxia-induced depression, but this contribution is only revealed when adenosine A(1) receptors are blocked.