Effect of sex on ethanol consumption and conditioned taste aversion in adolescent and adult rats

Abstract

Rationale Vulnerability to alcoholism is determined by many factors, including the balance of pleasurable vs. aversive alcohol-induced sensations: pleasurable sensations increase drinking, aversive sensations reduce it. Both female sex and adolescent age are associated with fewer use-limiting effects of ethanol and more rapid development of alcohol abuse. Objectives This study assessed voluntary drinking and the aversive effects of alcohol in adolescent and adult male and female rats, to determine whether these measures are inversely related across the sexes and development. Methods Voluntary drinking of 20% ethanol in an every-other-day (EOD) availability pattern and the full dose-response relationship of ethanol CTA were assessed in male and female adolescent and adult rats. Results CTA was sex-specific in adult but not adolescent rats, with adult females exhibiting less aversion. Voluntary ethanol consumption varied according to age and interindividual differences in consumption patterns but was not sex-specific. Adolescents initially drank more than adults, exhibited greater day-to-day variation in consumption, were more susceptible to the alcohol deprivation effect, and took longer to establish individual differences in consumption patterns. Conclusions These results show that the evolution of drinking patterns differs in adolescents and adults. While a small cohort of adults establish high consumption patterns quickly, most adolescents drink at high levels initially and show marked deprivation-induced increases, but a significant percentage reduce intake as they become adult. High drinking adolescents do not ramp up like adults, but maintain adolescent drinking patterns into adulthood. Sex differences were not observed in EOD drinking during either adolescence or adulthood.

Sex differences in adult Wistar rats in the voluntary consumption of ethanol after pre-exposure to ethanol-induced flavor avoidance learning

“…After three pairings of the CSa and 1.5 g/kg ethanol, males were consuming 94.1% less CSa than they were at baseline; females were consuming 68.9% less (see Table 1). These results are consistent with those obtained by several other research groups (Caihol and Mormede, 2002;Morales et al, 2014;Schramm-Sapyta et al, 2014;Sherrill et al, 2011a). In fact, a relative sensitivity of males as compared to females with this preparation is generally reported, although the strength of the sex difference varies across studies and is dependent upon a number of factors (see Busse et al, 2005).…”

“…One factor that has received considerable attention is the sex of the subject used in the FAL procedure. Sex differences in FAL have been examined with a variety of compounds such as lithium chloride (LiCl) (Chambers et al, 1981;Dacanay et al, 1984), cocaine (Busse et al, 2005;Jones et al, 2006) and ethanol (Caihol and Mormede, 2002;Morales et al, 2014;Schramm-Sapyta et al, 2014;Sherrill et al, 2011a). The relative sensitivity of males (compared to females) within this preparation is generally reported, although the strength of the sex difference varies across studies and is dependent upon a number of factors (see Busse et al, 2005).…”

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.…”

Adolescent rats fail to demonstrate a LiCl-induced pre-exposure effect: Implications for the balance of drug reward and aversion in adolescence

“…For example, adolescent rats consistently display weaker drug-induced CTA compared to adults when conditioned with a number of different compounds such as amphetamine (Infurna & Spear, 1979), cocaine (Schramm-Sapyta et al, 2006), ethanol (SchrammSapyta et al, 2010Vetter-O'Hagen et al, 2009), morphine , and nicotine (Wilmouth and Spear, 2004;Shram et al, 2006), among others (Anderson et al, 2010;Anderson et al, 2014;Flax et al, 2015;Schramm-Sapyta et al, 2007;Wetzel et al, 2014). The relatively weaker taste avoidance reported in adolescents has been suggested to be a function of their relative insensitivity to the drug's aversive effects (Schramm-Sapyta et al, 2014), i.e., the drug is less aversive in adolescent subjects and thus induces a weaker avoidance response.…”