Kainate receptor-mediated presynaptic inhibition converges with presynaptic inhibition mediated by Group II mGluRs and long-term depression at the hippocampal mossy fiber-CA3 synapse.
Kainate receptors (KARs) effect depression of glutamate release at hippocampal mossy fiber-CA3 (MF-CA3) synapses by a metabotropic action involving adenylyl cyclase (AC) inhibition, cAMP reduction, and diminished protein kinase A (PKA) activation. Using hippocampal slices, we show here that KAR activation interferes with the depression of glutamate release produced by Group II metabotropic glutamate receptor stimulation and low frequency stimulation (LFS)-induced long-term depression (LTD), also expressed through presynaptic AC/cAMP/PKA at MF-CA3 synapses. The mutual occlusion of depression mediated by presynaptic KARs, Group II mGluR and LFS-induced LTD suggests their mechanistic convergence at the MF-CA3 synapse and thus invokes KARs in synaptic plasticity manifest in LTD.
Negrete-Díaz
J V
JV
División de Neurociencias, Universidad Pablo de Olavide, Seville, Spain.
Sihra
T S
TS
Delgado-García
J M
JM
Rodríguez-Moreno
A
A
D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D003627:Data Interpretation, Statistical; D004594:Electrophysiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D019599:Mossy Fibers, Hippocampal / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D018408:Patch-Clamp Techniques; D018092:Kainic Acid Receptors / Q000502:physiology*; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D017661:Receptors, Presynaptic / Q000502:physiology*; D013569:Synapses / Q000502:physiology*
D017868:Cyclic AMP-Dependent Protein Kinases; D018691:Excitatory Amino Acid Antagonists; D007608:Kainic Acid; D018092:Kainic Acid Receptors; D018094:Receptors, Metabotropic Glutamate; D017661:Receptors, Presynaptic; C108822:metabotropic glutamate receptor 2