The long-term effects of stress and kappa opioid receptor activation on conditioned place aversion in male and female California mice

•Low dose of kappa opioid receptor agonist induced aversion in control, but not stressed, females.•High dose of kappa opioid receptor agonist induced aversion in control and stressed males.•Stress and kappa agonist increased EGR1 activity in the nucleus accumbens in females.