Animal models of fetal alcohol spectrum disorders: impact of the social environment

Abstract

Animal models of fetal alcohol spectrum disorder (FASD) have been used to demonstrate the specificity of alcohol's teratogenic effects and some of the underlying changes in the central nervous system (CNS) and, more recently, to explore ways to ameliorate the effects of alcohol. The main point of this review is to highlight research findings from the animal literature which point to the impact of the social context or social behavior on the effect(s) of alcohol exposure during development, and also to point to research questions about the social environment and effects of prenatal alcohol exposure that remain to be answered. Alcohol exposure during early development alters maternal responding to the exposed pup in a variety of ways and the alteration in maternal responding could alter later stress responsivity and adult maternal and social behavior of the exposed offspring. Environmental enrichment and voluntary exercise have been shown to ameliorate some of alcohol's impact during development, but the roles of enhanced social interactions in the case of enrichment and of social housing during voluntary exercise need to be more fully delineated. Similarly, the role of social context across the lifespan, such as social housing, social experiences, and contact with siblings, needs further study. Because of findings that alcohol during development alters DNA methylation patterns and that there are alterations in the maternal care of the alcohol-exposed offspring, epigenetic effects and their relationship to social behavior in animal models of FASD are likely to become a fruitful area of research. Because of the simpler social behavior and the short lifespan of rodents, animal models of FASD can be useful in determining how the social context impacts the effects of alcohol exposure during development.

Fig. 1

Ethanol exposure during the combined prenatal and postnatal period alters the pattern of the frequency of ultrasonic vocalizations in isolated rat pups over development (Kelly, Lugo, and Marino, unpublished findings). Rat pups were isolated from their dam and ultrasonic vocalizations were detected using a bat detector. The litter was the unit of analysis and no pup was tested more than twice over the testing period. There are 15–17 animals of approximately equal numbers of males and females per data point. There were no sex differences in the frequency of ultrasonic vocalizations. The stars indicate a significant difference between the ethanol-treated group and both control groups on that postnatal day. Error bars represent standard errors of the mean (SEMs).