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 andspecific consequences on neuronal activity and behavior, with respect totraditional free-access paradigms (Carnicella et al., 2014). In order to exploregender-related effects, this study aimed at assessing the consequences of twodifferent patterns of alcohol self-administration on peculiar feminine behavioralrepertoire, such as deprivation phenotype and maternal care. Animalsunderwent long-term, home cage, two-bottle “alcohol (20% v/v) or water”choice regimen, with continuous (7 days a week) or intermittent (3 days aweek) access, and were tested for alcohol intake and preference. During acutedeprivation, they were tested for behavioral reactivity in the open field;anxiety-like behavior in the traditional- and fear-potentiated elevated plusmaze; novelty-induced exploration and recognition memory in the novel objectrecognition test; response to natural reward in saccharin preference test;depressive-like behavior in the forced-swim test. Animals were alcoholdeprivedduring mating and resumed self-administration from late gestationand throughout lactation. Home-cage undisturbed maternal behavior wasassessed until weaning. Results show that rats exposed to intermittent accessparadigm displayed higher alcohol intake and preference with respect to ratswith continuous access (p<0.001). During deprivation, rats exposed tointermittent access manifested reduced response to fear, novelty and reward(p<0.001), and depressive-like behavior (p<0.001), whereas rats exposed tocontinuous 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 intermittentalcohol access (p<0.001). In conclusion, long-term alcohol drinking inducesprofound alterations in the neuroadaptive systems underlying affectivity andreward, leading to alcohol-deprivation phenotypes and disruption of maternalcarebehaviour in a drinking pattern-related manner.