title: Altered expression of K+ -Cl- cotransporters affects fast paired-pulse inhibition during GABA receptor activation in the gerbil hippocampus.
abstract: K+ -Cl- cotransporter (KCC) plays an important role in maintaining neuronal activity. However, the effect of seizure activity or pharmacological manipulation of GABAergic transmission on KCC expression remains to be clarified. Therefore, the present study was performed to investigate whether seizure activity or GABA receptor agonist treatment changes KCC expression in the gerbil hippocampus. Furthermore, the effect of blockade of KCC on inhibitory transmission in the dentate gyrus was identified following applications of GABA receptor agonists. The distribution of KCC immunoreactivity in the hippocampus was similarly detected between seizure-resistant (SR) and seizure-sensitive (SS) gerbils. Baclofen (a GABAB receptor agonist) treatment markedly increased KCC expression in the gerbil hippocampus. Baclofen treatment significantly reduced paired-pulse inhibition in the dentate gyrus. Furosemide (a KCC inhibitor) treatment amplified the effect of baclofen on paired-pulse responses. In contrast, muscimol (a GABAA receptor agonist) treatment reduced KCC expression. Enhanced paired-pulse inhibition by muscimol treatment was not affected by furosemide treatment. These findings suggest that seizure activity in the gerbil may not affect KCC expression in the hippocampus. In addition, altered KCC immunoreactivity induced by baclofen or muscimol may play an important role in maintaining or regulating inhibitory transmission during GABA receptor activation.
authors.affiliation: Department of Anatomy, College of Medicine, Hallym University, Chunchon, Kangwon-Do, 200-702, South Korea. tckang@hallym.ac.kr
authors.forename: Tae-Cheon
authors.initials: TC
authors.lastname: Kang
authors.forename: Duk-Soo
authors.initials: DS
authors.lastname: Kim
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Kwak
authors.forename: Ki-Yeon
authors.initials: KY
authors.lastname: Yoo
authors.forename: In-Koo
authors.initials: IK
authors.lastname: Hwang
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Jung
authors.forename: Moo Ho
authors.initials: MH
authors.lastname: Won
authors.forename: Oh-Shin
authors.initials: OS
authors.lastname: Kwon
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Choi
mesh_terms: D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D005071:Evoked Potentials; D018755:GABA Agonists / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D005849:Gerbillinae; D006624:Hippocampus / Q000502:physiology*; D007150:Immunohistochemistry; D009118:Muscimol / Q000494:pharmacology; D018079:Receptors, GABA / Q000502:physiology*; D027981:Symporters / Q000235:genetics*; D000096922:K Cl- Cotransporters
chemical_list: D001418:Baclofen; D018755:GABA Agonists; D009118:Muscimol; D018079:Receptors, GABA; D027981:Symporters; D000096922:K Cl- Cotransporters