Drinking pattern matters: effects on maternal care and offspring vulnerability to alcohol in rats

Alcohol drinking during pregnancy and post-partum period is a major concern because of the persistent neurobehavioral deficits in the offspring, which include increased vulnerability to substance abuse (1). The intermittent pattern of alcohol consumption induces higher drinking levels and deeper neurobiological changes in addiction-related brain regions, with respect to traditional free-access paradigms in male rats (2, 3). Nevertheless, no studies investigated on the effects of the drinking pattern on female subjects during pregnancy and perinatal time. To this aim, this study explored the consequences of continuous vs. intermittent drinking pattern on maternal behaviour and on offspring vulnerability to alcohol, during adulthood. Dams were given two-bottle choice to water and 20% alcohol with either continuous- or intermittent access (CA vs IA), along a 12-week period. They suspended alcohol drinking during breeding and resumed alcohol self-administration from late gestation throughout lactation, when they were assessed for home-cage undisturbed maternal behaviour. In the adulthood, alcohol-exposed offspring were assessed for alcohol drinking behaviour in a free-choice paradigm and tested for the deprivation effect. Our results show that alcohol consumption and preference significantly decreased in IA group during pregnancy, returning to baseline during lactation. Alcohol drinking was able to disrupt spontaneous maternal behaviour, especially in IA exposed dams. On the other hand, perinatal CA exposure did not increase alcohol-drinking behaviour in the offspring with respect to controls, while rats perinatally exposed to IA displayed a high vulnerability to alcohol, in terms of drinking behaviour and deprivation effect. In conclusion, this study indicates for the first time that the pattern of alcohol consumption can be responsible for different extents of maternal behaviour disruption and detrimental consequences in the offspring. Therefore gender- but also pattern-related differences should be taken into account for contrasting alcohol abuse and dependence, especially during perinatal time.   1. McMurray MS, Williams SK, Jarrett TM, Cox ET, Fay EE, Overstreet DH, Walker CH, Johns JM. Neurotoxicol Teratol. 2008;30(6):475-86. 2. Stuber GD, Hopf FW, Hahn J, Cho SL, Guillory A, Bonci A. Alcohol Clin Exp Res. 2008 Oct;32(10):1714-20 3. George O, Sanders C, Freiling J, Grigoryan E, Vu S, Allen CD, Crawford E, Mandyam CD, Koob GF. Proc Natl Acad Sci U S A. 2012;109(44):18156-61