title: Experimental early-life febrile seizures induce changes in GABA(A) R-mediated neurotransmission in the dentate gyrus.
abstract: OBJECTIVE
  Febrile seizures (FS), the most frequent seizure type during childhood, have been linked to temporal lobe epilepsy (TLE) in adulthood. Yet, underlying mechanisms are still largely unknown. Altered γ-aminobutyric acid (GABA)ergic neurotransmission in the dentate gyrus (DG) circuit has been hypothesized to be involved. This study aims at analyzing whether experimental FS change inhibitory synaptic input and postsynaptic GABA(A) R function in dentate granule cells.
  
  
  METHODS
  We applied an immature rat model of hyperthermia (HT)-induced FS. GABA(A) R-mediated neurotransmission was studied using whole-cell patch-clamp recordings from dentate granule neurons in hippocampal slices within 6-9 days post-HT.
  
  
  RESULTS
  Frequencies of spontaneous inhibitory postsynaptic currents (sIPSCs) were reduced in HT rats that had experienced seizures, whereas sIPSC amplitudes were enhanced. Whole-cell GABA responses revealed a doubled GABA(A) R sensitivity in dentate granule cells from HT animals, compared to that of normothermic (NT) controls. Analysis of sIPSCs and whole-cell GABA responses showed similar kinetics in postsynaptic GABA(A) Rs of HT and NT rats. quantitative real-time polymerase chain reaction (qPCR) experiments indicated changes in DG GABA(A) R subunit expression, which was most pronounced for the α3 subunit.
  
  
  CONCLUSIONS
  The data support the hypothesis that FS persistently alter neuronal excitability.
authors.affiliation: BIOMED Research Institute, Hasselt University/Transnational University Limburg, Diepenbeek, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Swijsen
authors.forename: Ariel
authors.initials: A
authors.lastname: Avila
authors.forename: Bert
authors.initials: B
authors.lastname: Brône
authors.forename: Daniel
authors.initials: D
authors.lastname: Janssen
authors.forename: Govert
authors.initials: G
authors.lastname: Hoogland
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Rigo
mesh_terms: D000367:Age Factors; D000818:Animals; D018891:Dentate Gyrus / Q000502:physiology*; D053444:Inhibitory Postsynaptic Potentials / Q000502:physiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology*; D003294:Seizures, Febrile / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology
chemical_list: D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid