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Gene Expression Changes in Glutamate and GABA ‐A Receptors, Neuropeptides, Ion Channels, and Cholesterol Synthesis in the Periaqueductal Gray Following Binge‐Like Alcohol Drinking by Adolescent Alcohol‐Preferring (P) Rats
Author(s) -
McClintick Jeanette N.,
McBride William J.,
Bell Richard L.,
Ding ZhengMing,
Liu Yunlong,
Xuei Xiaoling,
Edenberg Howard J.
Publication year - 2016
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/acer.13056
Subject(s) - periaqueductal gray , endocrinology , medicine , binge drinking , glutamate receptor , receptor , biology , alcohol , biochemistry , central nervous system , alcohol consumption , midbrain
Background Binge drinking of alcohol during adolescence is a serious public health concern with long‐term consequences, including increased pain, fear, and anxiety. The periaqueductal gray ( PAG ) is involved in processing pain, fear, and anxiety. The effects of adolescent binge drinking on gene expression in this region have yet to be studied. Methods Male adolescent alcohol‐preferring (P) rats were exposed to repeated binge drinking (three 1‐hour sessions/d during the dark/cycle, 5 days/wk for 3 weeks starting at 28 days of age; ethanol intakes of 2.5 to 3 g/kg/session). We used RNA sequencing to assess the effects of ethanol intake on gene expression. Results Ethanol significantly altered the expression of 1,670 of the 12,123 detected genes: 877 (53%) decreased. In the glutamate system, 23 genes were found to be altered, including reduction in 7 of 10 genes for metabotropic and NMDA receptors. Subunit changes in the NMDA receptor may make it less sensitive to ethanol. Changes in GABA A genes would most likely increase the ability of the PAG to produce tonic inhibition. Five serotonin receptor genes, 6 acetylcholine receptor genes, and 4 glycine receptor genes showed decreased expression in the alcohol‐drinking rats. Opioid genes (e.g., Oprk1 , Oprm1 ) and genes for neuropeptides linked to anxiety and panic behaviors (e.g., Npy1r ) had mostly decreased expression. Genes for 27 potassium, 10 sodium, and 5 calcium ion channels were found to be differentially expressed. Nine genes in the cholesterol synthesis pathway had decreased expression, including Hmgcr , encoding the rate‐limiting enzyme. Genes involved in the production of myelin also had decreased expression. Conclusions The results demonstrate that binge alcohol drinking during adolescence produces developmental changes in the expression of key genes within the PAG ; many of these changes point to increased susceptibility to pain, fear, and anxiety, which could contribute to excessive drinking to relieve these negative effects.