title: Eag1, Eag2, and SK3 potassium channel expression in the rat hippocampus after global transient brain ischemia.
abstract: Transient global brain ischemia causes delayed neuronal death in the hippocampus that has been associated with impairments in hippocampus-dependent brain function, such as mood, learning, and memory. We investigated the expression of voltage-dependent Kcnh1 and Kcnh5, ether à go-go-related Eag1 and Eag2 (K(V) 10.1 and K(V) 10.2), and small-conductance calcium-activated SK3 (K(Ca) 2.3, Kcnn3) K(+) channels in the hippocampus in rats after transient global brain ischemia. We tested whether the expression of these channels is associated with behavioral changes by evaluating the animals in the elevated plus maze and step-down inhibitory avoidance task. Seven or tweny-eight days after transient global brain ischemia, one group of rats had the hippocampus bilaterally dissected, and mRNA levels were determined. Seven days after transient global brain ischemia, the rats exhibited a decrease in anxiety-like behavior and memory impairments. An increase in anxiety levels was detected 28 days after ischemia. Eag2 mRNA downregulation was observed in the hippocampus 7 days after transient global brain ischemia, whereas Eag1 and SK3 mRNA expression remained unaltered. This is the first experimental evidence that transient global brain ischemia temporarily alters Eag2. The number of intact-appearing pyramidal neurons was substantially decreased in CA1 and statistically measurable in CA2, CA3, and CA4 hippocampal subfields compared with sham control animals 7 or 28 days after ischemia. mRNA expression in the rat hippocampus. The present results provide further information for the characterization of the physiological role of Eag2 channels in the central nervous system.
authors: Department of Pharmacology, University of Maringá (UEM), Maringá, Paraná, Brazil. rmmwoliveira@uem.br
authors: R M Weffort
authors: RM
authors: de Oliveira
authors: S
authors: S
authors: Martin
authors: C Lino
authors: CL
authors: de Oliveira
authors: H
authors: H
authors: Milani
authors: A P
authors: AP
authors: Schiavon
authors: S
authors: S
authors: Joca
authors: L A
authors: LA
authors: Pardo
authors: W
authors: W
authors: Stühmer
authors: E A
authors: EA
authors: Del Bel
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D015536:Down-Regulation; D051638:Ether-A-Go-Go Potassium Channels / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000378:metabolism*
chemical_list: D051638:Ether-A-Go-Go Potassium Channels; C496886:Kcnh1 protein, rat; C402401:Kcnh5 protein, rat; C496901:Kcnn3 protein, rat; D051640:Small-Conductance Calcium-Activated Potassium Channels