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Group II metabotropic glutamate receptors inhibit neurotransmitter release from thalamocortical synapses
Author(s) -
Mateo Zaira,
Porter James
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1210-d
Subject(s) - metabotropic glutamate receptor , glutamate receptor , metabotropic glutamate receptor 2 , neuroscience , metabotropic glutamate receptor 1 , metabotropic glutamate receptor 7 , chemistry , metabotropic glutamate receptor 5 , excitatory postsynaptic potential , metabotropic receptor , nmda receptor , biology , receptor , inhibitory postsynaptic potential , biochemistry
Group II metabotropic glutamate receptors (mGluRs) are known to inhibit glutamate release from various synapses; however, it is unknown whether they modulate thalamocortical synapses. We examined the effect of the group II mGluR agonist DCG IV on thalamocortical EPSCs evoked by stimulating the internal capsule in mouse brain slices. Since previous studies demonstrated that the reduction in glutamate release induced by group II mGluRs was greater in young animals, we initially examined the effects of DCG IV in slices from younger mice (P6–12). DCG IV reduced the EPSCs by 45% and increased the paired pulse ratio. This suggests that group II mGluRs inhibit glutamate release from thalamocortical synapses presynaptically. Furthermore, the reduction induced by DCG IV was reversed by the group II mGluR antagonist, LY341495. In slices from older animals (P18–21), DCG IV reduced thalamocortical EPSCs by only 11% suggesting a developmental decline in group II mGluR‐mediated inhibition. We conclude that activation of group II mGluRs modulates thalamocortical synapses by inhibiting glutamate release and this inhibition appears to play a developmental role in thalamocortical processing. Supported by F34 GM070406 ‐01 and S06 GM08239.