title: Presynaptic K+ channel modulation is a crucial ionic basis of neuronal damage induced by ischemia in rat hippocampal CA1 pyramidal neurons.
abstract: The ischemia-induced synaptic potentiation (ISP) during and/or after brain ischemia has been suggested to be one of the crucial factors responsible for irreversible neuronal damage of hippocampal CA1 pyramidal neurons. However, the presynaptic modulation mechanism that leads to neuronal damage during and/or after ischemia was still unknown. By combining electrophysiological methods and infra-red differential interference contrast (IR-DIC) imaging procedures, we showed for the first time that ISP is the result of extraordinary presynaptic depolarization in association with the suppression of 4-aminopyridine (4-AP) sensitive K(+) channels at the presynaptic sites. Furthermore, we also showed that the 4-AP sensitive presynaptic K(+) channels played a crucial role in inducing neuronal damage at a very acute phase of ischemia-induced neuronal damage and would be a therapeutic target against the neuronal damage after brain ischemia.
authors.affiliation: Second Department of Physiology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takagi
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kodama
authors.forename: Minoru
authors.initials: M
authors.lastname: Saito
authors.forename: Hideo
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology*; D011188:Potassium / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism*; D017966:Pyramidal Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D015761:4-Aminopyridine; D011188:Potassium