title: GABAA, not GABAB, receptor shows subunit- and spatial-specific alterations in the hippocampus of seizure prone gerbils.
abstract: In the present study, we investigated site-specific expressions of GABA(A) and GABA(B) receptor subunits in the seizure-sensitive (SS) and seizure-resistant (SR) gerbil hippocampus to elucidate the function of the gamma-aminobutyric acid (GABA) receptor in seizure activity in this animal. There were no differences of the immunoreactivities of GABA(B) receptor and some GABA(A) receptor subunits (alpha3, alpha4, pan beta and delta) in the hippocampus between SR and SS gerbils. The alpha1 subunit expression was mainly detected in interneurons of stratum radiatum and hilar region of dentate gyrus in the SR gerbil. However, in SS gerbil, interneurons were nearly devoid of alpha1 subunit immunoreactivity and mainly detected in the molecular layer of dentate gyrus. In SR gerbil, alpha2 subunit immunoreactivity was detected in Ammon's horn, particularly in the CA2 region. In SS gerbil, granule cell layer of the dentate gyrus in SS gerbil showed strong alpha2 subunit immunoreactivity. The distribution of alpha5 and gamma2 subunit immunoreactivity in the hippocampus was similarly detected in SR and SS gerbil. However, alpha5 immunodensity of SR gerbil was slightly lower than that of SS gerbil in CA1 region and was slightly strong than that of SS gerbil in subiculum. These differences in distribution of GABA(A) receptor, not GABA(B) receptor, in the SR and SS gerbil hippocampus may indicate that abnormal hyperactive neuronal discharges are occurred in SS gerbil, which presumably result in spontaneous and repetitive seizure activity in this animal.
authors.affiliation: Department of Anatomy, College of Medicine, Hallym University, Kangwon-Do, Chunchon 200-702, South Korea.
authors.forename: In Koo
authors.initials: IK
authors.lastname: Hwang
authors.forename: Seung-Kook
authors.initials: SK
authors.lastname: Park
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: An
authors.forename: Ki-Yeon
authors.initials: KY
authors.lastname: Yoo
authors.forename: Duk-Soo
authors.initials: DS
authors.lastname: Kim
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Jung
authors.forename: Moo Ho
authors.initials: MH
authors.lastname: Won
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Choi
authors.forename: Oh-Shin
authors.initials: OS
authors.lastname: Kwon
authors.forename: Tae-Cheon
authors.initials: TC
authors.lastname: Kang
mesh_terms: D000818:Animals; D005849:Gerbillinae; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D018080:Receptors, GABA-B / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism; D012640:Seizures / Q000378:metabolism*
chemical_list: D011963:Receptors, GABA-A; D018080:Receptors, GABA-B