RRC ID 27722
Author Harada Y, Nagao Y, Shimizu S, Serikawa T, Terada R, Fujimoto M, Okuda A, Mukai T, Sasa M, Kurachi Y, Ohno Y.
Title Expressional analysis of inwardly rectifying Kir4.1 channels in Noda epileptic rat (NER).
Journal Brain Res
Abstract The inwardly rectifying potassium channel subunit Kir4.1 is expressed in brain astrocytes and involved in spatial K(+) buffering, regulating neural activity. To explore the pathophysiological alterations of Kir4.1 channels in epileptic disorders, we analyzed interictal expressional levels of Kir4.1 in the Noda epileptic rat (NER), a hereditary animal model for generalized tonic-clonic (GTC) seizures. Western blot analysis showed that Kir4.1 expression in NERs was significantly reduced in the occipito-temporal cortical region and thalamus. However, the expression of Kir5.1, another Kir subunit mediating spatial K(+) buffering, remained unaltered in any brain regions examined. Immunohistochemical analysis revealed that Kir4.1 was primarily expressed in glial fibrillary acidic protein (GFAP)-positive astrocytes (somata) and foot processes clustered around neurons proved with anti-neuronal nuclear antigen (NeuN) antibody. In NERs, Kir4.1 expression in astrocytic processes was region-selectively diminished in the amygdaloid nuclei (i.e., medial amygdaloid nucleus and basomedial amygdaloid nucleus) while Kir4.1 expression in astrocytic somata was unchanged. Furthermore, the amygdala regions with reduced Kir4.1 expression showed a marked elevation of Fos protein expression following GTC seizures. The present results suggest that reduced activity of astrocytic Kir4.1 channels in the amygdala is involved in limbic hyperexcitability in NERs.
Volume 1517
Pages 141-9
Published 2013-6-23
DOI 10.1016/j.brainres.2013.04.009
PII S0006-8993(13)00522-2
PMID 23603404
MeSH Amygdala / pathology* Animals Disease Models, Animal Epilepsy, Tonic-Clonic / genetics Epilepsy, Tonic-Clonic / metabolism* Epilepsy, Tonic-Clonic / pathology* Gene Expression Regulation / genetics* Gene Expression Regulation / physiology Glial Fibrillary Acidic Protein / metabolism Male Neuroglia / metabolism* Neurons / metabolism Oncogene Proteins v-fos / metabolism Phosphopyruvate Hydratase / metabolism Potassium Channels, Inwardly Rectifying / genetics Potassium Channels, Inwardly Rectifying / metabolism* Rats Rats, Inbred WKY Rats, Mutant Strains
IF 2.733
Times Cited 16
Rats NER/Kyo(strainID=26)