title: Contribution of extrasynaptic N-methyl-D-aspartate and adenosine A1 receptors in the generation of dendritic glutamate-mediated plateau potentials.
abstract: Thin basal dendrites can strongly influence neuronal output via generation of dendritic spikes. It was recently postulated that glial processes actively support dendritic spikes by either ceasing glutamate uptake or by actively releasing glutamate and adenosine triphosphate (ATP). We used calcium imaging to study the role of NR2C/D-containing N-methyl-d-aspartate (NMDA) receptors and adenosine A1 receptors in the generation of dendritic NMDA spikes and plateau potentials in basal dendrites of layer 5 pyramidal neurons in the mouse prefrontal cortex. We found that NR2C/D glutamate receptor subunits contribute to the amplitude of synaptically evoked NMDA spikes. Dendritic calcium signals associated with glutamate-evoked dendritic plateau potentials were significantly shortened upon application of the NR2C/D receptor antagonist PPDA, suggesting that NR2C/D receptors prolong the duration of calcium influx during dendritic spiking. In contrast to NR2C/D receptors, adenosine A1 receptors act to abbreviate dendritic and somatic signals via the activation of dendritic K(+) current. This current is characterized as a slow-activating outward-rectifying voltage- and adenosine-gated current, insensitive to 4-aminopyridine but sensitive to TEA. Our data support the hypothesis that the release of glutamate and ATP from neurons or glia contribute to initiation, maintenance and termination of local dendritic glutamate-mediated regenerative potentials.
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: Katerina D
authors.initials: KD
authors.lastname: Oikonomou
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: Mandakini B
authors.initials: MB
authors.lastname: Singh
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Rich
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: Shaina M
authors.initials: SM
authors.lastname: Short
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA antic@neuron.uchc.edu.
authors.forename: Srdjan D
authors.initials: SD
authors.lastname: Antic
mesh_terms: D000818:Animals; D003712:Dendrites / Q000378:metabolism* / Q000502:physiology; D003979:Diazonium Compounds; D018698:Glutamic Acid / Q000378:metabolism*; D051379:Mice; D016202:N-Methylaspartate / Q000378:metabolism*; D010880:Piperidines; D017397:Prefrontal Cortex / Q000166:cytology* / Q000502:physiology; D017966:Pyramidal Cells / Q000378:metabolism*; D011725:Pyridines; D043682:Receptor, Adenosine A1 / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D055366:Synaptic Potentials / Q000502:physiology*
chemical_list: D003979:Diazonium Compounds; D010880:Piperidines; D011725:Pyridines; D043682:Receptor, Adenosine A1; D016194:Receptors, N-Methyl-D-Aspartate; C056729:4-(2'-pyridyldithio)benzyldiazoacetate; D018698:Glutamic Acid; D016202:N-Methylaspartate; C010739:ifenprodil
keywords: calcium imaging; dendritic spike; neuromodulation; plateau potential