Early social isolation augments alcohol consumption in rats

Abstract

There is a considerable degree of individual vulnerability for alcohol use disorder (AUD) as only a subpopulation of individuals who regularly consume alcohol develop AUD. It is therefore very important to understand the factors and mechanisms that contribute towards the individual risk for AUD. In this respect, social influences, in particular during development, may be relevant for AUD as disruptions in early social experiences are associated with an increased risk for AUD. Social play, the most prominent form of social behaviour shown by young mammals, is rewarding and considered to be important for social, emotional and cognitive development. Recent studies suggest that early social isolation, effectively depriving animals from social play, increases the risk for addictive behaviour. The aim of this study was therefore to explore the long-term consequences of early social isolation on alcohol consumption and motivation for alcohol. To this end, rats were socially isolated from postnatal days 21-42, followed by 4 weeks of social housing, and voluntary alcohol consumption and operant responding for alcohol were determined in adulthood. We observed enhanced levels of alcohol consumption in adulthood in previously isolated rats, whereas operant responding for alcohol was not altered. The impact of early social isolation was independent of the individual variation in alcohol consumption. These data indicate that social isolation, during a developmental period when social play is highly abundant, enhances the propensity to consume alcohol in adulthood. This implies that early social experience may be a protective factor against excessive alcohol use.

Drug-taking in a socio-sexual context enhances vulnerability for addiction in male rats

“…Recently it has been emphasized that preclinical addiction studies have failed to predict outcomes in human subjects, and that a major shortcoming of these studies is a lack of consideration of social influences in the experimental design [2], and studies henceforth will need to address this pitfall. Even with this increased awareness, the social influences on drug addiction vulnerability thus far have largely focused on effects of social isolation or providing social interactions to such isolated animals [34][35][36][37]. In addition, effects of social contact during drug taking behavior have been demonstrated.…”

Dopaminergic neurotransmission in ventral and dorsal striatum differentially modulates alcohol reinforcement

“…The rats were trained and tested, as previously described (Lesscher et al ., ; Spoelder et al ., ), in operant conditioning chambers (29.5 cm L, 24 cm W, 25 cm H; Med Associates, Georgia, VT, USA), situated in light‐ and sound‐attenuating cubicles equipped with a ventilation fan. Each chamber was equipped with two 4.8‐cm‐wide retractable levers, placed 11.7 cm apart and 6 cm from the grid floor.…”

In search of predictive endophenotypes in addiction: insights from preclinical research

“…Social experience during this period has profound effects on neural and behavioral developments. Thus, rats isolated from other rats during the peri‐adolescence period show a heightened locomotor reactivity to novelty and behavioral sensitivity to psychostimulant drugs (Baarendse et al ; Fone & Porkess ) as well as increased alcohol consumption (Lesscher et al ). This social intervention also has protracted effects on prefrontal and striatal circuits (Bianchi et al ; Dalley et al ; Hall et al ) consistent with the evidence that social play depends on the integrity of prefrontal cortex and striatum (van Kerkhof et al ).…”