Presynaptic kainate receptor mediation of frequency facilitation at hippocampal mossy fiber synapses.
Inhibition of transmitter release by presynaptic receptors is widespread in the central nervous system and is typically mediated via metabotropic receptors. In contrast, very little is known about facilitatory receptors, and synaptic activation of a facilitatory autoreceptor has not been established. Here we show that activation of presynaptic kainate receptors can facilitate transmitter release from hippocampal mossy fiber synapses. Synaptic activation of these presumed ionotropic kainate receptors is very fast (<10 ms) and lasts for seconds. Thus, these presynaptic kainate receptors contribute to the short-term plasticity characteristics of mossy fiber synapses, which were previously thought to be an intrinsic property of the synapse.
Departments of Cellular and Molecular Pharmacology and Physiology, University of California, San Francisco, CA 94143, USA.
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D
Schmitz
J
J
Mellor
R A
RA
Nicoll
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials; D018698:Glutamic Acid / Q000378:metabolism*; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D019599:Mossy Fibers, Hippocampal / Q000502:physiology*; D009473:Neuronal Plasticity; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000187:drug effects / Q000502:physiology; D018092:Kainic Acid Receptors / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018691:Excitatory Amino Acid Antagonists; D018698:Glutamic Acid; D007608:Kainic Acid; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate