A history of bingeing on fat enhances cocaine seeking and taking.

Abstract

Binge eating and substance dependence are disorders characterized by a loss of control over consummatory behaviors. Given the common characteristics of these two types of disorders, it is not surprising that the comorbidity between eating disorders and substance abuse disorders is high (20–40%; Conason et al., 2006). It is unknown, however, whether loss of control in one disorder predisposes an individual to loss of control in the other. The present study, therefore, used a rodent model to test whether a history of binge eating would augment subsequent responding for cocaine. Using the limited access protocol described by Corwin et al. (1998), 45 adult male Sprague-Dawley rats were maintained on one of four dietary protocols for a period of six weeks: chow only (Chow; n=9), continuous access to an optional source of dietary fat (Ad Lib; n=12), 1-h access to an optional source of dietary fat daily (Daily; n=12), or 1-h access to an optional source of dietary fat on Monday, Wednesday, and Friday (MWF; n=12). All four groups also had unrestricted access to a nutritionally complete diet of chow and water. Fat-bingeing behaviors developed in the MWF rats, the group with the most restricted access to the optional fat. Thereafter, cocaine-seeking and –taking behaviors were assessed in all rats using a self-administration protocol modified from that described by Deroche-Gamonet et al. (2004), which focus on the motivation for and preoccupation with obtaining and consuming drug (assessed using a progressive ratio (PR) schedule of reinforcement) and persistence in responding for drug during periods of signaled drug non-availability (SNA). Rats with the MWF history tended to take more cocaine late in fixed ratio (FR) training, they persisted in their efforts to obtain cocaine in the face of signaled non-availability, worked harder for cocaine on a PR schedule of reinforcement, and exhibited more goal-directed behavior towards the cocaine-associated operandum. These results demonstrate a link between binge-type intake of fat and the development of drug-seeking and -taking behaviors, suggesting that a history of fat bingeing may predispose individuals to exhibit more robust “addiction-like” behaviors toward a substance of abuse. Thus, it appears that conditions promoting excessive behavior toward one substance (e.g., a palatable fatty food) beget excessive behavior toward another (e.g., cocaine).

Rodent Models of Binge Eating: Are They Models of Addiction?

“…Rats with a history of bingeing on fat worked harder for cocaine and responded more often during periods of signaled cocaine nonavailability than did rats without the binge history (Puhl et al 2011). These results bear on the comorbidity between binge eating and illicit drug abuse or dependence (Hudson et al 2007).…”

Once is too much: Conditioned aversion develops immediately and predicts future cocaine self-administration behavior in rats.

“…Environmental enrichment during adulthood reduces acquisition of cocaine self-administration in male rats (Puhl et al, 2012). Chronic sleep deprivation, on the other hand, greatly augments acquisition of cocaine self-administration and the willingness to work for drug (Puhl, Boisvert, Guan, Fang, & Grigson, 2013; Puhl, Fang, & Grigson, 2009), as does a history of having binged on fat (Puhl et al, 2011). Thus, having identified an early indicator of vulnerability (i.e., conditioned aversive taste reactivity behavior to the drug-paired cue), future studies also will seek to intervene, behaviorally and/or pharmacologically, to prevent this early transition from use to abuse and addiction.…”

“…Intra-jugular catheters were custom-made in our laboratory as described previously (Puhl, Blum, Acosta-Torres, & Grigson, 2012; Puhl, Cason, Wojnicki, Corwin, & Grigson, 2011; Twining et al, 2009). General maintenance of catheter patency involved daily examination and flushing of catheters with heparinized saline.…”

Rodent models for compulsive alcohol intake

“…Moreover, escalation of drug use is paralleled by footshock-resistant cocaine seeking in a subpopulation of rats (Chen et al, 2013; Jonkman et al, 2012). Furthermore, long-term access to palatable food leads to subsequent aversion-resistant food intake (Johnson & Kenny, 2010), and an interesting recent study (Puhl, Cason, Wojnicki, Corwin, & Grigson, 2011) found that an escalating, intermittent-access, binge intake of fat led to subsequent development of addiction-like cocaine responding (increased progressive ratio and extinction responding). However, there is also evidence to suggest that escalation of drug use may not be a proxy for compulsivity, as was demonstrated by Ahmed and colleagues using a paradigm where rats can choose between receiving a cocaine infusion or sweetened water (for review, see Ahmed, 2012).…”