From binge eating to binge drinking: A new and robust paradigm for assessing binge ethanol self‐administration in male rats

RUIZ LEYVA, LEANDRO; VÁZQUEZ ÁGREDOS, ANA; JIMÉNEZ GARCÍA, ANA M.; LÓPEZ GUARNIDO, OLGA; PLA, ANTONIO; PAUTASSI, RICARDO MARCOS; MORÓN HENCHE, IGNACIO; CENDÁN, CRUZ MIGUEL

ADDICTION BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2022 vol. 27

1355-6215

Animal models of alcohol (ethanol) self-administration are crucial to dissect the neurobiological mechanisms underlying alcohol dependence. Yet only a few of these induce pharmacologically relevant levels of alcohol consumption and rarely the alcohol self-administration co-occurs with other addictive behaviors. The present study aims to validate a novel model of voluntary ethanol consumption in male Wistar rats, in which ethanol access follows a binge eating experience. Over 10 sessions, Wistar rats were exposed to BINGE or CONTROL eating (i.e., the ingestion of 11.66 kcal/3min and 0.97 kcal/3min, respectively; derived from a highly palatable food), immediately followed by two-bottle choice intake tests (2%, 6%, 10% or 14% w/w ethanol vs. water). Rats exposed to BINGE eating drank significantly more 6% or 10% (w/w) ethanol than CONTROL peers, reaching up to 6.3 gEtOH/kg. Rats stimulated with 2%, 6%, 10% or 14% ethanol after BINGE eating, but not those given those ethanol concentrations after CONTROL eating, exhibited significant within-group increases in ethanol drinking. This ethanol consumption was not altered by quinine adulteration (up to 0.1 g/L) and it was blocked by naltrexone (10 mg/kg), administered immediately before BINGE eating. Blood ethanol levels significantly correlated with ethanol consumption; and the more ethanol consumed, the greater the distance travelled in an Open Field test conducted after the two-bottle choice test. Altogether, this self-administration model seems a valid and robust alternative with remarkable potential for research on different stages of the alcohol addiction and, particularly, to assess interactions between alcohol consumption and others addictive-like behaviors.