Increased alcohol drinking in isolate-housed alcohol-preferring rats.

Abstract

Alcoholism is a complex disorder influenced by interactions between genetic and environmental risk factors. This study examined the influence of isolate housing on ethanol intake in alcohol-preferring (P) and non-alcohol-preferring (NP) rats. Rats were isolate-housed or pair-housed for 8 weeks when between 45 and 96 days old. Ethanol drinking was assessed using a 24-hr preference test (10% ethanol vs. water) and 20-min limited access tests. A behavioral test battery was used to assess anxiety-like, depressive-like, acoustic startle, and motor behavior. Isolate housing increased home cage drinking in both lines and increased limited access drinking selectively in P rats. Isolation also reduced swim test immobility and prepulse inhibition in P rats and increased locomotor stereotypies in NP rats. Taken together, these data demonstrate that LinexEnvironment interactions influence the effects of isolation. Furthermore, isolation selectively increased ethanol intake in high drinking P rats. This effect was not correlated with changes in other behaviors. Selective enhancement of limited access ethanol drinking in P rats may represent a model whereby genetic liability to excessive drinking is enhanced by specific environmental exposures.

Individual Differences and Social Influences on the Neurobehavioral Pharmacology of Abused Drugs

“…Exceptions where social context is protective against alcohol consumption are studies comparing chronic isolation versus social housing for an extended period, which show that chronic isolation stress increases alcohol consumption and preference for high concentrations of alcohol compared with social housing (Wolffgramm, 1990;Wolffgramm and Heyne, 1991;Ehlers et al, 2007). In contrast, studies have found social facilitation of drinking using pre-exposure to a demonstrator rat that had been exposed to alcohol (Hunt et al, 2001(Hunt et al, , 2000.…”

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

“…Variables that have been previously investigated in adolescent self-administration paradigms include sex, age, ethanol fluid concentration, isolate-housing and use of different sipper-tube types; however, these studies provided 24-hour access to the ethanol solutions (Bell et al, 2006;Brunell and Spear, 2005;Doremus et al, 2005;Ehlers et al, 2007;Fullgrabe et al, 2007;Lancaster et al, 1996;Siciliano and Smith, 2001). In the present experiment, male and female adolescent and adult rats were compared for ethanol self-administration behavior during one hour limited-access sessions, which have been proposed to model binge-like behavior (Martinetti et al, 2006).…”

The Effects of Stress on Measures of Alcohol Drinking in Rodents

“…Rats bred for increased ethanol consumption generally demonstrate increases in drinking following stress (but see Chester, Blose, Zweifel, & Froehlich, 2004). Stressors that have been shown to increase drinking in the alcohol-preferring lines include footshock (HAD, P, and AA rats), immobilization stress (P rats), maternal separation from PND 1-21 (AA rats), and 16.5 weeks of isolation housing (P rats; Chester et al, 2004;Ehlers, Walker, Pian, Roth, & Slawecki, 2007;Roman, Gustafsson, Hyytia, & Nylander, 2005;Vengeliene et al, 2003). On the other hand, footshock stress increased alcohol preference in outbred rats with a low preference for ethanol and decreased it in rats with a high preference (Volpicelli, Ulm, & Hopson, 1990).…”