gamma-DGG is a competitive AMPA receptor blocker.
gamma-DGG (γ-DGG), a competitive AMPA receptor blocker that blocks less at higher glutamate concentration. At 200-400 μM, gamma-DGG in the bath reduces the miniature EPSC (mEPSC) amplitude by 26±2% (n=5 synapses), and shifts both the mEPSC amplitude distribution and the cumulative probability curve to the left[1]. gamma-DGG (γ-DGG) is the most effective antagonist of the excitatory post-synaptic potentials (e.p.s.p.s). Its action is reversible and not associated with any change in the passive membrane properties of the granule cells or in the apparent reversal potential of the e.p.s.p. Quantal analysis shows that the reduction in the e.p.s.p. paralleled the decrease in quantal size rather than quantal content, confirming a post-synaptic site of the action of gamma-DGG[2].
References:
[1]. Wu XS, et al. The origin of quantal size variation: vesicular glutamate concentration plays a significant role. J Neurosci. 2007 Mar 14;27(11):3046-56.
[2]. Crunelli V, et al. Blockade of amino acid-induced depolarizations and inhibition of excitatory post-synaptic potentials in rat dentate gyrus. J Physiol. 1983 Aug;341:627-40.