The kainate receptor subunit GluR6 mediates metabotropic regulation of the slow and medium AHP currents in mouse hippocampal neurones.
Kainate receptors (KARs) play an important role in synaptic physiology, plasticity and pathological phenomena such as epilepsy. However, the physiological implications for single cells and neuronal networks of the distinct expression patterns of KAR subunits are unknown. One intriguing effect of KAR activation is a long-term change to intrinsic neuronal excitability and neuronal firing patterns, such as single-spike and spike-burst firing. In this study, we describe the role of kainate receptor subunits in the metabotropic regulation of the slow and medium afterhyperpolarization (AHP) currents (I(sAHP), I(mAHP)). Using whole-cell patch-clamp recordings from CA3 pyramidal cells of wild-type (WT) and KAR knockout mice, we show that the kainate-induced decrease of I(sAHP) and I(mAHP) amplitude is protein-kinase-C-dependent and absent in GluR6(-/-) but not GluR5(-/-) pyramidal neurones. Our findings suggest that activation of GluR6-containing KARs modulates AHP amplitude, and influences the firing frequency of pyramidal neurones.
Fisahn
André
A
Laboratory of Cellular and Synaptic Neurophysiology, NICHD, NIH, Bethesda, MD 20892, USA. andre.fisahn@neuro.ki.se
Heinemann
Stephen F
SF
McBain
Chris J
CJ
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004594:Electrophysiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D018092:Kainic Acid Receptors / Q000235:genetics / Q000502:physiology*; D000097806:GluK2 Kainate Receptor
D018690:Excitatory Amino Acid Agonists; D007608:Kainic Acid; D018092:Kainic Acid Receptors; D000097806:GluK2 Kainate Receptor