Abstract
To investigate the role of glutamate receptors in the synaptic transmission between dendrites in the AOB, evoked synaptic currents were measured from mitral cells in slice preparations prepared from 23- to 36-day-old Balb/c mice. To evoke dendrodendritic inhibition, a depolarizing voltage step from -70 mV was applied to a mitral cell under the whole-cell configuration. Under control conditions, the voltage step evokes GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs). We have demonstrated that, in Mg2+-free solution, the NMDA receptor antagonist D,L-APV significantly blocked the IPSCs. The previous studies also demonstrated that an agonist for group II metabotropic glutamate receptors (mGluR2/mGluR3), DCG-IV, suppressed dendrodendritic inhibition whereas the mGluR2/mGluR3 antagonist LY341495 enhanced it.
In the present study, in order to conduct further investigation on the role of mGluR2/mGluR3 in the synaptic transmission, the IPSCs were recorded from mitral cells prepared from mGluR2 mutant mice. Genetic ablation of mGluR2 markedly impaired the effects of DCG-IV and LY341495 on the IPSCs, respectively. The present results provide the further implication that mGluR2, as well as NMDA receptors, plays an important role in reciprocal transmission between mitral and granule cells in the mouse AOB. [Jpn J Physiol 54 Suppl:S177 (2004)]
