Ethanol decreases Purkinje neuron excitability by increasing GABA release in rat cerebellar slices.

Details

Serval ID
serval:BIB_DC96EE5EF60A
Type
Article: article from journal or magazin.
Collection
Publications
Title
Ethanol decreases Purkinje neuron excitability by increasing GABA release in rat cerebellar slices.
Journal
The Journal of pharmacology and experimental therapeutics
Author(s)
Mameli M., Botta P., Zamudio P.A., Zucca S., Valenzuela C.F.
ISSN
1521-0103 (Electronic)
ISSN-L
0022-3565
Publication state
Published
Issued date
12/2008
Peer-reviewed
Oui
Volume
327
Number
3
Pages
910-917
Language
english
Notes
Publication types: Journal Article ; Research Support, N.I.H., Extramural
Publication Status: ppublish
Abstract
Cerebellar Purkinje neurons (PNs) receive inhibitory GABAergic input from stellate and basket cells, which are located in the outer and inner portions of the molecular layer, respectively. Ethanol (EtOH) was recently shown to increase GABAergic transmission at PNs via a mechanism that involves enhanced calcium release from presynaptic internal stores (J Pharmacol Exp Ther 323:356-364, 2007). Here, we further characterized the effect of EtOH on GABA release and assessed its impact on PN excitability. Using whole-cell patch-clamp electrophysiological techniques in cerebellar vermis parasagittal slices, we found that EtOH acutely increases the frequency but not the amplitude or half-width of miniature and spontaneous inhibitory postsynaptic currents (IPSCs). EtOH significantly increased the amplitude and decreased the paired pulse ratio of IPSCs evoked by stimulation in the outer but not inner molecular layer. In current clamp, EtOH decreased both the amplitude of excitatory postsynaptic potentials evoked in PNs by granule cell axon stimulation and the number of action potentials triggered by these events; these effects depended on GABA(A) receptor activation because they were not observed in presence of bicuculline. Loose-patch cell-attached PN recordings revealed that neither the spontaneous action potential firing frequency nor the coefficient of variation of the interspike interval was altered by acute EtOH exposure. These findings suggest that EtOH differentially affects GABAergic transmission at stellate cell- and basket cell-to-PN synapses and that it modulates PN firing triggered by granule cell axonal input. These effects could be in part responsible for the cerebellar impairments associated with acute EtOH intoxication.

Keywords
Action Potentials/drug effects, Animals, Cerebellum/metabolism, Electrophysiology, Ethanol/pharmacology, Excitatory Postsynaptic Potentials, Inhibitory Postsynaptic Potentials, Miniature Postsynaptic Potentials, Purkinje Cells/drug effects, Purkinje Cells/physiology, Rats, Synaptic Potentials/drug effects, gamma-Aminobutyric Acid/metabolism
Pubmed
Web of science
Create date
31/01/2017 15:41
Last modification date
20/08/2019 16:01
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