Intermittent- vs continuous alcohol access in female rats: Effects on deprivation phenotype and maternal behavior as a consequence of the drinking pattern

In male rats, the intermittent alcohol access paradigm produces relevant and specific consequences on neuronal activity and behavior, with respect to traditional free-access paradigms (Carnicella et al., 2014). In order to explore gender-related effects, this study aimed at assessing the consequences of two different patterns of alcohol self-administration on peculiar feminine behavioral repertoire, such as deprivation phenotype and maternal care. Animals underwent long-term, home cage, two-bottle “alcohol (20% v/v) or water” choice regimen, with continuous (7 days a week) or intermittent (3 days a week) access, and were tested for alcohol intake and preference. During acute deprivation, they were tested for behavioral reactivity in the open field; anxiety-like behavior in the traditional- and fear-potentiated elevated plus maze; novelty-induced exploration and recognition memory in the novel object recognition test; response to natural reward in saccharin preference test; depressive-like behavior in the forced-swim test. Animals were alcoholdeprived during mating and resumed self-administration from late gestation and throughout lactation. Home-cage undisturbed maternal behavior was assessed until weaning. Results show that rats exposed to intermittent access paradigm displayed higher alcohol intake and preference with respect to rats with continuous access (p<0.001). During deprivation, rats exposed to intermittent access manifested reduced response to fear, novelty and reward (p<0.001), and depressive-like behavior (p<0.001), whereas rats exposed to continuous access displayed a prominent anxiety-like behavior (p<0.001). Moreover, alcohol drinking decreased nursing and overall maternal behaviour; the most detrimental consequences were observed in dams with intermittent alcohol access (p<0.001). In conclusion, long-term alcohol drinking induces profound alterations in the neuroadaptive systems underlying affectivity and reward, leading to alcohol-deprivation phenotypes and disruption of maternalcare behaviour in a drinking pattern-related manner.