Skip to main page content
U.S. flag

An official website of the United States government

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Mar;42(2):83-9.
doi: 10.1016/j.alcohol.2007.12.001.

Dissociable effects of ethanol consumption during the light and dark phase in adolescent and adult Wistar rats

Brendan M Walker  1 , Jennifer L Walker, Cindy L Ehlers
Affiliations

Dissociable effects of ethanol consumption during the light and dark phase in adolescent and adult Wistar rats

Brendan M Walker et al. Alcohol. 2008 Mar.

Abstract

In adolescence, high levels of drinking over short episodes (binge drinking) is commonly seen in a proportion of the population. Because adolescence is an important neurodevelopmental period, the effects of binge drinking on brain and behavior has become a significant health concern. However, robust animal models of binge drinking in rats are still being developed and therefore further efforts are needed to optimize paradigms for inducing maximal self-administration of alcohol. In the present experiment, 1-h limited-access self-administration sessions were instituted to model excessive drinking behavior in adolescent and adult Wistar rats. In addition to age, the involvement of sex and phase within the light/dark cycle (i.e., drinking in the light or dark) on sweetened 5% ethanol intake were also evaluated over 14 limited-access sessions using a between-groups design. The results of the experiment showed that over 14 limited-access sessions, sweetened ethanol intake (g/kg) was significantly higher for adolescents compared to adults. Females were also found to drink more sweetened ethanol as compared to males. Additionally, drinking in the light produced a robust increase in sweetened ethanol intake (g/kg) in adolescents, as compared to adults during the light phase and as compared to both adolescent and adult rats drinking in the dark. Furthermore, the increase in ethanol consumption observed in adolescents drinking during the light phase was dissociable from sweetened solution intake patterns. These results identify that age, sex, and time of day all significantly influence consumption of sweetened ethanol in Wistar rats. Knowledge of these parameters should be useful for future experiments attempting to evaluate the effects of self-administered ethanol exposure in adult and adolescent rats.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Mean (± S.E.M.) ethanol intake (g/kg) from the fourteen one-hour limited-access sessions for adolescent and adult (A), male and female (B) and light or dark phase (C) Wistar rats. Inset of each figure corresponds to the mean (+S.E.M.) ethanol intake (g/kg) of the fourteen sessions (*** = p < 0.001, ** = p < 0.01 and * = p < 0.05).
Figure 2
Figure 2
Left panel: Mean (±S.E.M.) ethanol intake (g/kg) for adolescent and adult Wistar rats during the fourteen one-hour limited-access light (A) or dark (B) phase consumption sessions. Right panel (C): Mean (+ S.E.M.) ethanol intake of the fourteen sessions for adolescent and adult rats drinking during the light or dark phase of the light/dark cycle (* = p < 0.001 when compared to Adult/Light, § = p < 0.001 when compared to Adolescent/Dark, and † = p < 0.001 when compared to Adult/Dark groups).
Figure 3
Figure 3
Mean (± S.E.M.) sweetened solution (SS) intake (g/kg) from the fourteen one-hour limited-access sessions for adolescent Wistar rats during the light or dark phase of their circadian cycle. Inset of each figure corresponds to the mean (+S.E.M.) SS intake (g/kg) of the fourteen sessions.
Figure 4
Figure 4
The BALs for separate groups of Wistar rats were collected on three occasions and plotted against ethanol intake (g/kg) for that session. Significant associations were found for not only the individual groups (n = 30, ps < 0.001), but also the entire sample (n = 240, p < 0.001).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Adams N. Sex differences and the effects of tail pinch on ethanol drinking in Maudsley rats. Alcohol. 1995;12:463–468. - PubMed
    1. Almeida OF, Shoaib M, Deicke J, Fischer D, Darwish MH, Patchev VK. Gender differences in ethanol preference and ingestion in rats. The role of the gonadal steroid environment. J Clin Invest. 1998;101:2677–2685. - PMC - PubMed
    1. Andrade MM, edito-Silva AA, Menna-Barreto L. Correlations between morningness-eveningness character, sleep habits and temperature rhythm in adolescents. Braz J Med Biol Res. 1992;25:835–839. - PubMed
    1. Andrade MM, Tome MF, Santiago ES, Lucia-Santos A, de Andrade TG. Longitudinal study of daily variation of rats’ behavior in the elevated plus-maze. Physiol Behav. 2003;78:125–133. - PubMed
    1. Bell RL, Rodd ZA, Sable HJ, Schultz JA, Hsu CC, Lumeng L, Murphy JM, McBride WJ. Daily patterns of ethanol drinking in peri-adolescent and adult alcohol-preferring (P) rats. Pharmacol Biochem Behav. 2006;83:35–46. - PubMed

Publication types