Interaction between trait and housing condition produces differential decision-making toward risk choice in a rat gambling task

Abstract

Poor decision-making is a core problem in psychiatric disorders such as pathological gambling and substance abuse. Both trait and environmental factors are considerably important to affect decision-making. However, it has not yet been systematically shown how they interact to affect risk preference in animal models evaluating decision-making. Here, we trained rats, housed in pairs or in isolation, in a touch screen chamber to detect the association between four different light signals on the screen and accompanied reward and punishment outcomes arranged with different schedules. Then, the rats were allowed to freely choose from 4 different light signals. Once animals showed a stabilized pattern of preference (risk-averse or risk-seeking), they were injected with saline or cocaine (a single injection per day for 7 days) followed by 2 weeks of withdrawal. Then, their preference of choice was re-tested in the touch screen chamber while they were cocaine challenged. All rats significantly changed their preference toward more risky choices when they were exposed to and challenged with cocaine, except those in the risk-averse/isolated housing group. These results indicate that the pre-existing trait toward risk and the housing condition interact to affect the quality of decision-making, and cocaine may help to aggravate this process.

Exposure to conditions of uncertainty promotes the pursuit of amphetamine

“…Cocaine-dependent individuals show a higher prevalence of pathological gambling than observed in the general population [36] and drugs like amphetamine are known to increase motivation to gamble [21] and to elicit enhanced striatal DA release [22] in pathological gamblers. In preclinical studies, rats previously exposed to psychomotor stimulant drugs show enhanced responding to and for amphetamine [7] and increased risky decision-making in a rodent gambling task [37]. Similarly, rats previously exposed to conditions of uncertainty also show enhanced responding to and for amphetamine (present findings), as well as increased risky decision-making [27].…”

Cued for risk: Evidence for an incentive sensitization framework to explain the interplay between stress and anxiety, substance abuse, and reward uncertainty in disordered gambling behavior

“…Sensitization of mesolimbic dopamine function results in the amplification of the neural mechanisms for incentive salience that transform ordinary levels of cue-triggered Bwant-ing^into excessive levels of urges to take drugs and gamble, and a persistent vulnerability to relapse (Boileau et al, 2014; W. Y. Kim, Cho, Kwak, & Kim, 2017;Leyton, 2007). This incentive sensitization also produces hyper-reactivity of the mesolimbic dopaminergic system in response to rewardrelated cues, resulting in heightened, intense bouts of cueinduced craving.…”

Impulsive Action and Impulsive Choice Are Differentially Expressed in Rats Depending on the Age at Exposure to a Gambling Task

“…Pre-training methods have been described in detail in our previous study ( 12 ). In brief, animals were trained once daily in a 30 min session, 5 days per week.…”

“…Similarly, adopting the basic principle of IGT, the rodent version of the gambling task (rGT), which shares many of the features of the human gambling tasks ( 7 ), has been developed by a few research groups ( 8 – 10 ). Recently, we adopted one of the previously developed rGT models ( 10 ), with a modification of the touch-screen chamber ( 11 ), and successfully trained rats to demonstrate decision-making toward risk-preference ( 12 ). In rGT, for rats to be trained to perform decision-making behaviors with gambling features, they require pre-training steps with multiple stages, one of which is very similar to the 5-CSRTT.…”