Differential effects of early exposure to alcohol on alcohol preference and blood alcohol levels in low- and high-anxious rats

Emotional disturbances emerge following alcohol withdrawal. The anxiolytic effect of alcohol may be one important motivation for its consumption in conditions where alcohol intake is anxiety reducing. Besides, early alcohol experience will predict future alcohol-related problems at some point in their lives. Rats classified according to their anxiety-like behavior phenotype show a higher preference for alcohol. Yet, despite preclinical studies have identified the behavioral and physiological effects of alcohol withdrawal, little has been shown on relapse to alcohol after a period of abstinence following intermittent long-term alcohol consumption in low-(LA) and high-anxiety (HA) phenotype rats. This study attempts to assess the role of emotional reactivity of early-aged LA and HA rats on later alcohol preference, through an operant response procedure. For this, a sweetened liquid fading procedure associated with a long-term and intermittent voluntary alcohol drinking was used, with the animals being tested on different withdrawal periods. Alcohol withdrawal symptoms were recorded, and blood alcohol levels were assessed at two intervals to examine the influence of anxiety phenotype on blood alcohol clearance. Data from HA control and HA withdrawn rats show that emotionality selectively influences alcohol preference. Blood alcohol decay was faster in HA than in LA alcohol pretreated rats. HA rats showed an ascending curve of alcohol intake, exhibiting a high level of alcohol drinking on withdrawal and withdrawal symptoms. Moreover, HA alcohol experienced rats show a high frequency of lever-pressing response during extinction, associated with a facilitation of bar-pressing recovery trials, an indication of alcohol-seeking behavior.