Repeated binge ethanol administration during adolescence enhances voluntary sweetened ethanol intake in young adulthood in male and female rats

Abstract

Binge alcohol consumption is a rising concern in the United States, especially among adolescents. During this developmental period alcohol use is usually initiated and has been shown to cause detrimental effects on brain structure and function as well as cognitive/behavioral impairments in rats. Binge models, where animals are repeatedly administered high doses of ethanol typically over a period of three or four days cause these effects. There has been little work conducted aimed at investigating the long-term behavioral consequences of repeated binge administration during adolescence on later ethanol-induced behavior in young adulthood and adulthood. The repeated four-day binge model may serve as a good approximate for patterns of human adolescent alcohol consumption as this is similar to a “bender” in human alcoholics. The present set of experiments examined the dose-response and sex-related differences induced by repeated binge ethanol administration during adolescence on sweetened ethanol (Experiment 1) or saccharin (Experiment 2) intake in young adulthood. In both experiments, on postnatal days (PND) 28–31, PND 35–38 and PND 42–45, ethanol (1.5, 3.0 or 5.0 g/kg) or water was administered intragastrically to adolescent rats. Rats underwent abstinence from PND 46–59. Subsequently, in young adulthood, ethanol and saccharin intake were assessed. Exposure to any dose of ethanol during adolescence significantly enhanced ethanol intake in adulthood. However, while female rats had higher overall g/kg intake, males appear to be more vulnerable to the impact of adolescent ethanol exposure on subsequently increased ethanol intake in young adulthood. Exposure to ethanol during adolescence did not alter saccharin consumption in young adulthood in male or female rats. Considering that adolescence is the developmental period in which ethanol experimentation and consumption is usually initiated, the present set of experiments demonstrate the importance of elucidating the impact of early binge-pattern ethanol exposure on the subsequent predisposition to drink later in life.

Sex, strain, and estrous cycle influences on alcohol drinking in rats

“…However, housing conditions are unlikely responsible for sex differences in alcohol drinking. As shown in Table 1, Sluyter et al (2000); Walker et al (2008); Vetter-O’Hagen et al (2009) and Maldonado-Devincci et al (2010) reported that group-housed females voluntarily drank more alcohol than males, whereas Schramm-Sapyta et al (2014) reported a lack of sex differences in voluntary drinking in single-housed rats. Moreover, Varlinskaya et al (2015) reported that adult males and females drank more alcohol under social circumstances than alone.…”

“…Decreases in alcohol consumption during estrus have been identified in female rats with synchronized cycles via gonadotropin-releasing hormone agonists (Roberts et al, 1998), and decreases in alcohol drinking have been reported during diestrus in adult female rats that were exposed to high alcohol levels during adolescence (Maldonado-Devincci et al, 2010). Progesterone and estrogen levels are known to fluctuate throughout the estrous cycle.…”

Reinforcing Properties and Neurochemical Response of Ethanol within the Posterior Ventral Tegmental Area Are Enhanced in Adulthood by Periadolescent Ethanol Consumption

“…Injections of EtOH during adolescence can result in a conditioned taste aversion to sweetened solutions and indeterminate effects on adult EtOH consumption (Gilpin et al, 2012). In contrast, adolescents injected with EtOH in a manner that does not produce taste aversion can enhance adult EtOH consumption (Pascual et al, 2007(Pascual et al, , 2009Maldonado-Devincci et al, 2010). Voluntary EtOH drinking during adolescence at a level that produces pharmacologically relevant levels of EtOH has been shown to enhance adult EtOH consumption (Walker and Ehlers, 2009;Strong et al, 2010;O'Tousa et al, 2013).…”

Sex Differences in Animal Models: Focus on Addiction

“…Male cynomolgus monkeys that are given limited access and unlimited access to alcohol drink more than females and attain higher blood alcohol levels (Vivian et al, 2001). However, female rodents drink more than males (Eriksson and Pikkarainen, 1968;Hutchins et al, 1981;Li and Lumeng, 1984;Lancaster and Spiegel, 1992;Lancaster et al, 1996;Almeida et al, 1998;Juárez and Barrios de Tomasi, 1999;Blanchard et al, 1993;Walker et al, 2008;Maldonado-Devincci et al, 2010;Gamsby et al, 2013).…”