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Rasgrf2 controls noradrenergic involvement in the acute and subchronic effects of alcohol in the brain

Research output: Contribution to journalArticle

Alanna C Easton, Andrea Rotter, Anbarasu Lourdusamy, Sylvane Desrivières, Alberto Fernández-Medarde, Teresa Biermann, Cathy Fernandes, Eugenio Santos, Johannes Kornhuber, Gunter Schumann, Christian P Müller

Original languageEnglish
Article numberN/A
Pages (from-to)N/A
Number of pages11
JournalPsychopharmacology
VolumeN/A
Issue numberN/A
DOIs
E-pub ahead of print2014

King's Authors

Abstract

Rationale
Alcohol addiction is a major psychiatric disease, and yet, the underlying molecular adaptations in the brain remain unclear. Recent evidence suggests a functional role for the ras-specific guanine-nucleotide releasing factor 2 (Rasgrf2) in alcoholism. Rasgrf2−/− mice consume less alcohol and show entirely absent dopamine responses to an alcohol challenge compared to wild types (WT).

Objective
In order to further investigate how Rasgrf2 modifies the acute and subchronic effects of alcohol in the brain, we investigated its effects on the noradrenergic and serotonergic systems.

Methods
We measured noradrenaline and serotonin activity in the brain by in vivo microdialysis and RNA expression by chip analysis and RT-PCR after acute and sub-chronic alcohol exposure in Rasgrf2−/− and WT mice.

Results
In vivo microdialysis showed a significantly reduced noradrenergic response and an absent serotonergic response in the nucleus accumbens (NAcc) and caudate putamen (CPu) after an alcohol challenge in Rasgrf2−/− mice. A co-expression analysis showed that there is a high correlation between Rasgrf2 and α2 adrenoceptor RNA expression in the ventral striatum in naïve animals. Accordingly, we further assessed the role of Rasgrf2 in the response of the noradrenergic system to subchronic alcohol exposure. A decrease in β1 adrenoceptor gene expression was seen in Rasgrf2+/+, but not Rasgrf2−/− mice following alcohol exposure. Conversely, alcohol resulted in a decrease in both β2 and α2 adrenoceptor gene expression in knockout but not WT Rasgrf2 mice.

Conclusions
These findings suggest that adaptations in the noradrenergic system contribute to the Rasgrf2 enhanced risk of alcoholism.

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