title: Reduced hippocampal GABAergic function in Wistar audiogenic rats.
abstract: Epilepsy is a neurological disorder associated with excitatory and inhibitory imbalance within the underlying neural network. This study evaluated inhibitory γ-amino-butyric acid (GABA)ergic modulation in the CA1 region of the hippocampus of male Wistar rats and Wistar audiogenic rats (aged 90 ± 3 days), a strain of inbred animals susceptible to audiogenic seizures. Field excitatory postsynaptic potentials and population spike complexes in response to Schaffer collateral fiber stimulation were recorded in hippocampal slices before and during application of picrotoxin (50 µM, 60 min), a GABA A antagonist, and the size of the population spike was quantified by measuring its amplitude and slope. In control audiogenic-resistant Wistar rats (N = 9), picrotoxin significantly increased both the amplitude of the population spike by 51 ± 19% and its maximum slope by 73 ± 21%. In contrast, in slices from Wistar audiogenic rats (N = 6), picrotoxin caused no statistically significant change in population spike amplitude (33 ± 46%) or slope (11 ± 29%). Data are reported as means ± SEM. This result indicates a functional reduction of GABAergic neurotransmission in hippocampal slices from Wistar audiogenic rats.
authors.affiliation: Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: L E
authors.initials: LE
authors.lastname: Drumond
authors.forename: C
authors.initials: C
authors.lastname: Kushmerick
authors.forename: P A M
authors.initials: PA
authors.lastname: Guidine
authors.forename: M C
authors.initials: MC
authors.lastname: Doretto
authors.forename: M F D
authors.initials: MF
authors.lastname: Moraes
authors.forename: A R
authors.initials: AR
authors.lastname: Massensini
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000187:drug effects* / Q000378:metabolism; D004827:Epilepsy / Q000378:metabolism*; D018756:GABA Antagonists / Q000494:pharmacology*; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D010852:Picrotoxin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D018756:GABA Antagonists; D010852:Picrotoxin; D005680:gamma-Aminobutyric Acid