Synaptic activation of AMPA receptors inhibits GABA release from cerebellar interneurons.
A single neurotransmitter elicits diverse physiological responses through activation of multiple receptor subtypes and/or heterosynaptic interactions involving distinct synaptic targets. We found that a typical excitatory transmitter released from the climbing fiber (CF) in the cerebellar cortex not only excited Purkinje cells directly but also presynaptically inhibited GABAergic transmission from interneurons converging on the same Purkinje cells. Both homosynaptic and heterosynaptic actions of the CF transmitter (possibly glutamate) were mediated by activation of AMPA receptors. Dual AMPA receptor-mediated functions of excitation and disinhibition may ensure transmission of cerebellar CF signals controlling sensorimotor coordination.
Satake
S
S
Laboratory of Molecular Neurobiology, Mitsubishi Kasei Institute of Life Sciences and CREST (Japan Science and Technology), 11 Minamiooya, Machida-shi, Tokyo 194-8511, Japan.
Saitow
F
F
Yamada
J
J
Konishi
S
S
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002531:Cerebellum / Q000166:cytology / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D008839:Microelectrodes; D009412:Nerve Fibers / Q000187:drug effects / Q000378:metabolism; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D011689:Purkinje Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism* / Q000494:pharmacology
D002614:Chelating Agents; D018691:Excitatory Amino Acid Antagonists; D018091:Receptors, AMPA; D005576:Colforsin; D004533:Egtazic Acid; D005680:gamma-Aminobutyric Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid