Abstract |
Ethanol causes pathological changes in GABAA receptor trafficking and function. These changes are mediated in part by ethanol activation of protein kinase A (PKA). The current study investigated the expression of the GABAA α1 and α4 subunits and the kinase anchoring protein AKAP150, as well as bicuculline-induced seizure threshold, at baseline and following acute injection of ethanol (3.5 g/kg IP) in a mouse line lacking the regulatory RIIβ subunit of PKA. Whole cerebral cortices were harvested at baseline, 1 h, or 46 h following injection of ethanol or saline and subjected to fractionation and western blot analysis. Knockout (RIIβ-/-) mice had similar baseline levels of PKA RIIα and GABAA α1 and α4 subunits compared to wild type (RIIβ+/+) littermates, but had deficits in AKAP150. GABAA α1 subunit levels were decreased in the P2 fraction of RIIβ-/-, but not RIIβ+/+, mice following 1 h ethanol, an effect that was driven by decreased α1 expression in the synaptic fraction. GABAA α4 subunits in the P2 fraction were not affected by 1 h ethanol; however, synaptic α4 subunit expression was increased in RIIβ+/+, but not RIIβ-/- mice, while extrasynaptic α4 and δ subunit expression were decreased in RIIβ-/-, but not RIIβ+/+ mice. Finally, RIIβ knockout was protective against bicuculline-induced seizure susceptibility. Overall, the results suggest that PKA has differential roles in regulating GABAA receptor subunits. PKA may protect against ethanol-induced deficits in synaptic α1 and extrasynaptic α4 receptors, but may facilitate the increase of synaptic α4 receptors.
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Authors | Stephen L Carlson, Todd K O'Buckley, Rhiannon Thomas, Todd E Thiele, A Leslie Morrow |
Journal | Neurochemical research
(Neurochem Res)
Vol. 39
Issue 6
Pg. 1079-87
(Jun 2014)
ISSN: 1573-6903 [Electronic] United States |
PMID | 24104609
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit
- Receptors, GABA-A
- Ethanol
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Topics |
- Animals
- Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit
(deficiency)
- Ethanol
(administration & dosage)
- Gene Expression Regulation
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, GABA-A
(biosynthesis)
- Seizures
(chemically induced, metabolism)
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