Altered brain activity during withdrawal from chronic alcohol is associated with changes in IL-6 signal transduction and GABAergic mechanisms in transgenic mice with increased astrocyte expression of IL-6. (August 2018)

• Record Type: Journal Article
• Authors: Gruol, Donna L.; Huitron-Resendiz, Salvador; Roberts, Amanda J.
• Is Part Of: Neuropharmacology. Volume 138(2018)
• Page Start: 32
• Page End: 46
• Publication Date: 2018-08
• Subjects: EEG -- GABAAR alpha-5 -- GABAAR alpha-1 -- STAT3 -- Neuroimmune -- Interleukin-6; Neuropsychopharmacology -- Periodicals; Autonomic Agents -- Periodicals; Neuropsychopharmacologie -- Périodiques; Neuropsychopharmacology; Periodicals; Electronic journals; 615.78
• DOI: 10.1016/j.neuropharm.2018.05.024
• Languages: English
• ISSNs: 0028-3908

Abstract

Abstract: Interleukin-6 (IL-6) is an important neuroimmune factor that is increased in the brain by alcohol exposure/withdrawal and is thought to play a role in the actions of alcohol on the brain. To gain insight into IL-6/alcohol/withdrawal interactions and how these interactions affect the brain, we are studying the effects of chronic binge alcohol exposure on transgenic mice that express elevated levels of IL-6 in the brain due to increased astrocyte expression (IL-6 tg) and their non-transgenic (non-tg) littermate controls. IL-6/alcohol/withdrawal interactions were identified by genotypic differences in spontaneous brain activity in electroencephalogram (EEG) recordings from the mice, and by Western blot analysis of protein activation or expression in hippocampus obtained from the mice after the final alcohol withdrawal period. Results from EEG studies showed frequency dependent genotypic differences in brain activity during withdrawal. For EEG frequencies that were affected by alcohol exposure/withdrawal in both genotypes, the nature of the effect was similar, but differed across withdrawal cycles. Differences between IL-6 tg and non-tg mice were also observed in Western blot studies of the activated form of STAT3 (phosphoSTAT3), a signal transduction partner of IL-6, and subunits of GABAA receptors (GABAA R). Regression analysis revealed that pSTAT3 played a more prominent role during withdrawal in the IL-6 tg mice than in the non-tg mice, and that the role of GABAA R alpha-5 and GABAA R alpha-1 in brain activity varied across genotype and withdrawal. Taken together, our results suggest that IL-6 can significantly impact mechanisms involved in alcohol withdrawal. Highlights: Alcohol exposure/withdrawal differentially effects brain EEG activity in IL-6 tg and non-tg mice. STAT3 and GABAA receptor subunits contribute to the effects of alcohol exposure/withdrawal on EEG activity. STAT3 plays a more prominent role during withdrawal in the IL-6 tg mice than in the non-tg mice. The role of GABAA R alpha-5 and GABAA R alpha-1 in brain EEG activity varies across genotype and withdrawal.