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Weaker Control of the Electrical Properties of Cerebellar Granule Cells by Tonically Active GABAA Receptors in the Ts65Dn Mouse Model of Down's Syndrome

Overview
Journal Mol Brain
Publisher Biomed Central
Date 2013 Jul 23
PMID 23870245
Citations 6
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Abstract

Background: Down's syndrome (DS) is caused by triplication of all or part of human chromosome 21 and is characterized by a decrease in the overall size of the brain. One of the brain regions most affected is the cerebellum, in which the number of granule cells (GCs) is markedly decreased. GCs process sensory information entering the cerebellum via mossy fibres and pass it on to Purkinje cells and inhibitory interneurons. How GCs transform incoming signals depends on their input-output relationship, which is adjusted by tonically active GABA(A) receptor channels.

Results: We report that in the Ts65Dn mouse model of DS, in which cerebellar volume and GC number are decreased as in DS, the tonic GABA(A) receptor current in GCs is smaller than in wild-type mice and is less effective in moderating input resistance and raising the minimum current required for action potential firing. We also find that tonically active GABA(A) receptors curb the height and broaden the width of action potentials in wild-type GCs but not in Ts65Dn GCs. Single-cell real-time quantitative PCR reveals that these electrical differences are accompanied by decreased expression of the gene encoding the GABA(A) receptor β3 subunit but not genes coding for some of the other GABA(A) receptor subunits expressed in GCs (α1, α6, β2 and δ).

Conclusions: Weaker moderation of excitability and action potential waveform in GCs of the Ts65Dn mouse by tonically active GABA(A) receptors is likely to contribute to atypical transfer of information through the cerebellum. Similar changes may occur in DS.

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References
1.
Das I, Reeves R . The use of mouse models to understand and improve cognitive deficits in Down syndrome. Dis Model Mech. 2011; 4(5):596-606. PMC: 3180223. DOI: 10.1242/dmm.007716. View

2.
Seja P, Schonewille M, Spitzmaul G, Badura A, Klein I, Rudhard Y . Raising cytosolic Cl- in cerebellar granule cells affects their excitability and vestibulo-ocular learning. EMBO J. 2012; 31(5):1217-30. PMC: 3297995. DOI: 10.1038/emboj.2011.488. View

3.
Arenz A, Bracey E, Margrie T . Sensory representations in cerebellar granule cells. Curr Opin Neurobiol. 2009; 19(4):445-51. DOI: 10.1016/j.conb.2009.07.003. View

4.
Stell B, Brickley S, Tang C, Farrant M, Mody I . Neuroactive steroids reduce neuronal excitability by selectively enhancing tonic inhibition mediated by delta subunit-containing GABAA receptors. Proc Natl Acad Sci U S A. 2003; 100(24):14439-44. PMC: 283610. DOI: 10.1073/pnas.2435457100. View

5.
Costa A, Grybko M . Deficits in hippocampal CA1 LTP induced by TBS but not HFS in the Ts65Dn mouse: a model of Down syndrome. Neurosci Lett. 2005; 382(3):317-22. DOI: 10.1016/j.neulet.2005.03.031. View