Regulation of neurotransmitter release by metabotropic glutamate receptors.
The G protein-coupled metabotropic glutamate (mGlu) receptors are differentially localized at various synapses throughout the brain. Depending on the receptor subtype, they appear to be localized at presynaptic and/or postsynaptic sites, including glial as well as neuronal elements. The heterogeneous distribution of these receptors on glutamate and nonglutamate neurons/cells thus allows modulation of synaptic transmission by a number of different mechanisms. Electrophysiological studies have demonstrated that the activation of mGlu receptors can modulate the activity of Ca(2+) or K(+) channels, or interfere with release processes downstream of Ca(2+) entry, and consequently regulate neuronal synaptic activity. Such changes evoked by mGlu receptors can ultimately regulate transmitter release at both glutamatergic and nonglutamatergic synapses. Increasing neurochemical evidence has emerged, obtained from in vitro and in vivo studies, showing modulation of the release of a variety of transmitters by mGlu receptors. This review addresses the neurochemical evidence for mGlu receptor-mediated regulation of neurotransmitters, such as excitatory and inhibitory amino acids, monoamines, and neuropeptides.
Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA.
J
J
Cartmell
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DD
Schoepp
D000818:Animals; D001921:Brain / Q000502:physiology*; D018846:Excitatory Amino Acids / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D009474:Neurons / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D013569:Synapses / Q000502:physiology
D018846:Excitatory Amino Acids; D018377:Neurotransmitter Agents; D018094:Receptors, Metabotropic Glutamate; D019204:GTP-Binding Proteins