Dendritic K+ channels contribute to spike-timing dependent long-term potentiation in hippocampal pyramidal neurons.
We investigated the role of A-type K(+) channels for the induction of long-term potentiation (LTP) of Schaffer collateral inputs to hippocampal CA1 pyramidal neurons. When low-amplitude excitatory postsynaptic potentials (EPSPs) were paired with two postsynaptic action potentials in a theta-burst pattern, N-methyl-d-aspartate (NMDA)-receptor-dependent LTP was induced. The amplitudes of the back-propagating action potentials were boosted in the dendrites only when they were coincident with the EPSPs. Mitogen-activated protein kinase (MAPK) inhibitors PD 098059 or U0126 shifted the activation of dendritic K(+) channels to more hyperpolarized potentials, reduced the boosting of dendritic action potentials by EPSPs, and suppressed the induction of LTP. These results support the hypothesis that dendritic K(+) channels and the boosting of back-propagating action potentials contribute to the induction of LTP in CA1 neurons.
Watanabe
Shigeo
S
Division of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
Hoffman
Dax A
DA
Migliore
Michele
M
Johnston
Daniel
D
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D003198:Computer Simulation; D003712:Dendrites / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005419:Flavonoids / Q000494:pharmacology; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009570:Nitriles / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002070:Butadienes; D004791:Enzyme Inhibitors; D005419:Flavonoids; D009570:Nitriles; D015221:Potassium Channels; C113580:U 0126; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one