Drinking despite adversity: behavioral evidence for a head down and push strategy of conflict‐resistant alcohol drinking in rats

Abstract

Compulsive alcohol drinking, where intake persists regardless of adverse consequences, plays a major role in the substantial costs of alcohol use disorder. However, the processes that promote aversion-resistant drinking remain poorly understood. Compulsion-like responding has been considered automatic and reflexive and also to involve higher motivation, since drinking persists despite adversity. Thus, we used lickometry, where microstructural behavioral changes can reflect altered motivation, to test whether conflict-resistant intake [quinine-alcohol (QuiA)] reflected greater automaticity or motivation relative to alcohol-only drinking (Alc). Front-loading during QuiA and Alc suggested incentive to drink in both. However, the relationship between total licking and intake was less variable during QuiA, as was lick volume, without changes in average responding. QuiA bout organization was also less variable, with fewer licks outside of bouts (stray licks) and fewer gaps within bouts. Interestingly, QuiA avoidance of stray licking continued into short bouts, with fewer short and more medium-length bouts, which was striking given their minor impact on intake. Instead, more effort at bout onset could allow short bouts to persist longer. Indeed, while QuiA licking was overall faster, QuiA bouts were especially fast at bout initiation. However, few QuiA changes individually predicted greater intake, perhaps suggesting an overarching strategy during aversion-resistant responding. Thus, our results indicate that aversion-resistant intake exhibited less variability, where increased automaticity could decrease need for awareness, and stronger bout initiation, which might prolong responding despite adversity. This may reflect a collective strategy, which we call Head Down and Push responding that facilitates conflict-resistant, compulsion-like intake.

Habitual Ethanol Seeking and Licking Microstructure of Enhanced Ethanol Self‐Administration in Ethanol‐Dependent Mice

“…To understand whether EtOH dependence altered patterns of consummatory behavior to contribute to the increase in EtOH consumption, we examined licking microstructure across training (Bin et al, ; Darevsky et al, ; Davis, ; Griffin et al, ; Robinson and McCool, ) (Fig. A,B ).…”

Sex Differences in Ethanol Reward Seeking Under Conflict in Mice

“…To our knowledge, minimal research has investigated sex differences in EtOH seeking that occurs despite adverse consequences. Research investigating compulsive‐like EtOH seeking includes a number of models, involving punished operant self‐administration and consumption of quinine‐adulterated EtOH (Darevsky et al., ; Hopf and Lesscher, ; Radke et al., ). Recent research has identified similar sensitivities to quinine adulteration in males and females, suggesting that sex differences are not present in this form of inflexible EtOH taking (Sneddon et al., ).…”

High Alcohol–Preferring Mice Show Reaction to Loss of Ethanol Reward Following Repeated Binge Drinking

“…Preclinical animal models of excessive EtOH consumption typically display "front-loading" behavior, wherein the amount or proportion of EtOH consumed is highly skewed toward the onset of EtOH access. This phenomenon is often observed following many drinking experiences and has therefore been suggested to reflect a progressive increase in the motivation to experience EtOH's subjective rewarding effects (Darevsky et al, 2018;Linsenbardt and Boehm, 2014;Linsenbardt and Boehm, 2015;Rhodes et al, 2007;Salling et al, 2018;Wilcox et al, 2014).…”