Summary
Introduction:
This article reports a study examining the effects of nicotine vapor exposure on approach behavior, weight gain, and cotinine levels in adolescent and adult female and male rats. The study used a passive vapor inhalation system and assessed nosepoke responses, physical signs of withdrawal, anxiety-like behavior, and plasma levels of cotinine.
Key Points:
* The study found that female rats displayed a larger increase in approach behavior toward a port that delivered nicotine vapor as compared to males, and this effect was larger in adolescents.
* In adolescent females, the results also revealed that approach behavior was correlated with withdrawal-induced increases in anxiety-like behavior, but not physical signs of withdrawal.
* adolescent rats gained more weight than adults, and this effect was larger in adolescent males regardless of their treatment condition.
* Female adolescents that exhibited the largest amount of nosepoke responses in the port that delivered nicotine also displayed the highest levels of the nicotine metabolite, cotinine.
* The study used a passive delivery system, and future studies will establish nicotine vapor self-administration.
* The study used a moderate concentration of nicotine (12 mg/mL) and flavorless e-liquids purchased from a commercial vendor.
* The exposure system consisted of four sealed chambers, each with two valve ports, and the chambers were carefully cleaned after every exposure session.
Main Message:
The study highlights the motivational effects of nicotine vapor in adolescent female rats, with approach behavior correlated with anxiety-like behavior during withdrawal. The study also highlights the importance of considering age and sex differences in nicotine use research, particularly in the context of the increasing popularity of nicotine vapor products. The findings suggest that nicotine vapor exposure may contribute to weight gain and nicotine dependence, and further research is needed to establish nicotine vapor self-administration in animal models.
Citation
Espinoza VE, Giner P, Liano I, Mendez Ia, O’Dell LE. Sex and age differences in approach behavior toward a port that delivers nicotine vapor. J Exp anal Behav. 2022;117:532-542. doi:10.1002/jeab.756
