Kiernan T. Callister

Tobacco use is the leading cause of death globally and in the United States. After decades of decline, driven by decreases in combusted tobacco use, nicotine product use has increased due to electronic nicotine delivery systems, also known as e‐cigarettes or vapes. Preclinical models of nicotine self‐administration can serve as important lodestars in the search for effective intervention and prevention tactics. Current variants of the preclinical models have substantial limitations, however. Therefore, we created the rodent electronic nicotine delivery system (RENDS), a novel low‐cost nonproprietary nose‐only preclinical model of nicotine aerosol self‐administration. We confirmed that RENDS sequesters nicotine aerosol in the nose port by measuring fine particulate matter (PM <2.5 microns) generated by e‐cigarettes. We also showed that rats robustly self‐administer flavored nicotine aerosol, resulting in high blood levels of cotinine (the major nicotine metabolite) and spontaneous somatic withdrawal symptoms. Thus, we provide validation of the operation and function of the RENDS, opening the door to an open‐source preclinical aerosol model of nicotine self‐administration that is relatively low in cost. Four existing operant chambers can be retrofitted with the RENDS for less than $325/chamber. All RENDS diagrams and plans for custom‐designed components are on Open Science Framework ( https://osf.io/x2pqf/?view_only=775b55435b8e428f98e6da384ef7889d ).

Tobacco use is the leading cause of death globally and in the U.S. After decades of decline, driven by decreases in combusted tobacco use, nicotine product use has increased due to Electronic Nicotine Delivery Systems, also known as e-cigarettes or vapes. Preclinical models of nicotine self-administration can serve as important lodestars in the search for effective intervention and prevention tactics. Current variants of the task have substantial limitations, however. Therefore, we created the Rodent Electronic Nicotine Delivery System, a novel low-cost non-proprietary nose-only preclinical model of nicotine aerosol self-administration. We confirmed that RENDS sequesters nicotine aerosol in the nose port by measuring fine particulate matter (PM < 2.5 microns) generated by e-cigarettes. We also showed that rats robustly self-administer flavored nicotine aerosol, resulting in high blood levels of cotinine (the major nicotine metabolite) and spontaneous somatic withdrawal symptoms. Thus, we provide strong validation of the operation and function of the RENDS, opening the door to an open-source preclinical aerosol model of nicotine self-administration that is relatively low cost. Four existing operant chambers can be retrofitted with the RENDS for less than $325/chamber. All RENDS diagrams and plans for custom designed components are on Open Science Framework ( https://osf.io/x2pqf/?view_only=775b55435b8e428f98e6da384ef7889d ).

We examined the zoographics, or the characteristics of nonhuman animal subjects, reported for the entirety of the Journal of the Experimental Analysis of Behavior (JEAB) through the most recent complete year (1958–2023). Animal sex in particular was evaluated to determine whether the lack of inclusion of female subjects in other disciplines extends to JEAB. Through systematic coding of all nonhuman empirical articles, we found consistent underreporting of most zoographics and a disproportionate use of male subjects relative to female subjects. Additionally, animal sex was commonly unreported and the inclusion of both male and female subjects was sparse. Recent years show some improvement, but greater inclusion is required. Lack of female subjects in research as well as underreporting of zoographics can generate unrepresentative results and hamper replication, generalization, and translation. We provide resources to guide future research and reporting suggestions such as equal inclusion and disaggregation of data by sex. We also clarify misunderstandings about the use of both sexes in research such as beliefs that it necessarily increases the cost of research.