Biological sex influences the contribution of sign-tracking and anxiety-like behavior toward remifentanil self-administration.

Behavioral Neuroscience, Vol 137(3), Jun 2023, 196-210; doi:10.1037/bne0000551Most people sample addictive drugs, but use becomes disordered in only a small minority. Two important factors that influence susceptibility to addiction are individual differences in personality traits and biological sex. The influence of traits on addiction-like behavior is well-characterized in preclinical models of cocaine self-administration, but less is understood in regards to opioids. How biological sex influences trait susceptibility to opioid self-administration is likewise less studied than psychostimulants. Thus, we sought to elucidate how biological sex and several addiction-relevant traits interact with the propensity to self-administer the opioid remifentanil. We first screened female (n = 19) and male (n = 19) rats for four addiction-relevant traits: impulsivity, novelty place-preference, anxiety-like behavior, and attribution of incentive value to reward cues. Rats were then trained to self-administer remifentanil in a “conflict model” of drug self-administration. Rats had to endure an electric shock to access the response manipulandum that triggered an intravenous infusion of remifentanil. In male rats, high anxiety-like behavior was positively correlated with the number of drug infusions if the shock level was low or completely absent. In females, sign-tracking was predictive of greater resistance to punishment during drug seeking; an effect that was mediated by anxiety-like b...
Source: Behavioral Neuroscience - Category: Neuroscience Source Type: research