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Individual Differences in Voluntary Ethanol Consumption Lead to Differential Activation of the Central Amygdala in Rats: Relationship to the Anxiolytic and Stimulant Effects of Low Dose Ethanol
Author(s) -
Sharko Amanda C.,
Kaigler Kris F.,
Fadel Jim R.,
Wilson Marlene A.
Publication year - 2013
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/j.1530-0277.2012.01907.x
Subject(s) - stria terminalis , anxiety , basolateral amygdala , elevated plus maze , anxiolytic , amygdala , anxiogenic , psychology , stimulant , central nucleus of the amygdala , basal (medicine) , ethanol , binge drinking , medicine , turnover , endocrinology , physiology , alcohol , chemistry , psychiatry , alcohol consumption , neuroscience , biochemistry , insulin , management , economics
Background Although alcohol use disorders and anxiety disorders are highly comorbid, the relationship between these 2 disorders is not fully understood. Previous work from our laboratory shows that anxiety‐like behavior is highly variable in outbred L ong‐ E vans rats and is related to the level of voluntary ethanol ( E t OH ) consumption, suggesting that basal anxiety state influences E t OH intake. To further examine the relationship between the acquisition of E t OH consumption and anxiety phenotype, L ong‐ E vans rats were assessed for anxiety‐like behavior and neuronal activation following voluntary E t OH consumption in a limited access drinking paradigm. Methods Rats were allowed to self‐administer E t OH (6% v/v) for 4 days using a limited access drinking in the dark paradigm and divided into high‐ and low‐drinking groups based on a median split of average daily E t OH intake. Immediately following the fourth drinking session, animals were tested on the elevated plus maze and evaluated for anxiety‐like behaviors. Fos immunoreactivity was assessed in the central and basolateral amygdala, as well as the bed nucleus of the stria terminalis. Results High E t OH drinkers spent significantly more time on the open arms of the plus maze than low E t OH drinkers. High E t OH drinkers also had increased locomotor activity as compared to both low E t OH drinkers and water drinkers. Fos immunoreactivity was positively correlated with E t OH consumption in all brain regions examined, although F os‐positive cell counts were only significantly different between high and low E t OH drinkers in the central amygdala ( C e A ). Conclusions Our findings demonstrate that outbred rats will voluntarily consume behaviorally effective doses of E t OH in a short‐term access model and E t OH consumption is positively correlated with increased neuronal activation in the C e A .