Logo image
Seizures and enhanced cortical GABAergic inhibition in two mouse models of human autosomal dominant nocturnal frontal lobe epilepsy
Journal article   Open access   Peer reviewed

Seizures and enhanced cortical GABAergic inhibition in two mouse models of human autosomal dominant nocturnal frontal lobe epilepsy

Alwin Klaassen, Joseph Glykys, Jamie Maguire, Cesar Labarca, Istvan Mody and Jim Boulter
Proceedings of the National Academy of Sciences - PNAS, Vol.103(50), pp.19152-19157
12/12/2006
DOI: 10.1073/pnas.0608215103
PMCID: PMC1681351
PMID: 17146052
url
https://doi.org/10.1073/pnas.0608215103View
Published (Version of record) Open Access

Abstract

Selected mutations in the human α4 or β2 neuronal nicotinic acetylcholine receptor subunit genes cosegregate with a partial epilepsy syndrome known as autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). To examine possible mechanisms underlying this inherited epilepsy, we engineered two ADNFLE mutations (Chrna4S252F and Chrna4+L264) in mice. Heterozygous ADNFLE mutant mice show persistent, abnormal cortical electroencephalograms with prominent delta and theta frequencies, exhibit frequent spontaneous seizures, and show an increased sensitivity to the proconvulsant action of nicotine. Relative to WT, electrophysiological recordings from ADNFLE mouse layer II/III cortical pyramidal cells reveal a >20-fold increase in nicotine-evoked inhibitory postsynaptic currents with no effect on excitatory postsynaptic currents. i.p. injection of a subthreshold dose of picrotoxin, a use-dependent γ-aminobutyric acid receptor antagonist, reduces cortical electroencephalogram delta power and transiently inhibits spontaneous seizure activity in ADNFLE mutant mice. Our studies suggest that the mechanism underlying ADNFLE seizures may involve inhibitory synchronization of cortical networks via activation of mutant α4-containing nicotinic acetylcholine receptors located on the presynaptic terminals and somatodendritic compartments of cortical GABAergic interneurons.
Biological Sciences cortex GABAegic interneuron nicotinic acetylcholine receptor

Details

Metrics

Logo image