Presynaptic kainate receptors that enhance the release of GABA on CA1 hippocampal interneurons.
We report that kainate receptors are present on presynaptic GABAergic terminals contacting interneurons and that their activation increases GABA release. Application of kainate increased the frequency of miniature inhibitory postsynaptic currents recorded in CA1 interneurons. Local applications of glutamate but not of AMPA or NMDA also increased GABA quantal release. Application of kainate as well as synaptically released glutamate reduced the number of failures of GABAergic neurotransmission between interneurons. Thus, activation of presynaptic kainate receptors increases the probability of GABA release at interneuron-interneuron synapses. Glutamate may selectively control the communication between interneurons by increasing their mutual inhibition.
Cossart
R
R
INMED, INSERM U29, Parc scientifique de Luminy, B.P. 13, 13273, Marseille, France
Tyzio
R
R
Dinocourt
C
C
Esclapez
M
M
Hirsch
J C
JC
Ben-Ari
Y
Y
Bernard
C
C
D000818:Animals; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D007608:Kainic Acid / Q000494:pharmacology; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018092:Kainic Acid Receptors / Q000187:drug effects / Q000502:physiology*; D017661:Receptors, Presynaptic / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018690:Excitatory Amino Acid Agonists; D018698:Glutamic Acid; D007608:Kainic Acid; D018092:Kainic Acid Receptors; D017661:Receptors, Presynaptic; D005680:gamma-Aminobutyric Acid