Amphibian populations worldwide are currently in decline. One approach to preventing extinction of some of the affected species is to create assurance colonies. These sustainable populations might some day be used to reestablish wild populations. One issue with creating assurance colonies is successful breeding; often difficulties arise when attempting to breed exotic animals in zoological institutions. Sexual conditioning, a form of Pavlovian conditioning, has been shown to improve breeding behavior. In this study the efficacy of sexual conditioning to improve breeding behavior in the dyeing dart frog (Dendrobates tinctorius) was tested. Pairs of frogs were exposed to one of three conditions. In two conditions pairs were trained with a stimulus (a flashing green light) that was either predictive of (experimental) or independent of (active control) exposure to a member of the opposite sex. The third condition was a no-treatment control. After training all three conditions were given five days to interact. Members of the experimental condition showed shorter latencies to a variety of breeding behaviors and produced more eggs than those in the control conditions. The sexual conditioning procedure was successful in increasing breeding behavior in this population of frogs.

Introduction

Reports in relatively healthy smokers suggest men are more sensitive than women to the subjective effects of reduced nicotine content cigarettes (RNCCs). We know of no reports examining sex differences in the relative reinforcing effects of RNCCs, an important outcome in assessing smoking's addiction potential. The aim of the present study is to address this gap by examining sex/gender differences on reinforcing effects while examining whether sex differences in subjective effects are discernible in vulnerable populations.

Methods

Secondary analysis of a within-subject, double-blinded experiment examining acute effects of cigarettes varying in nicotine content (0.4, 2.4, 5.2, 15.8 mg/g) among 169 adult smokers with psychiatric conditions or socioeconomic disadvantage. Effects of dose, sex, and their interaction were examined on reinforcing (concurrent-choice and Cigarette Purchase Task [CPT] testing), and subjective effects (Cigarette Evaluation Questionnaire [CEQ] and craving/withdrawal ratings).

Results

Reducing nicotine content decreased the relative reinforcing effects of smoking in concurrent-choice and CPT testing (p's < .05) with no significant effects of sex nor dose × sex/gender interactions. Reducing nicotine content decreased CEQ ratings with only a single significant effect of sex (higher Psychological Reward scores among women than men, p = .02) and no significant dose × sex/gender interactions. Results on craving/withdrawal paralleled those on the CEQ.

Conclusions

Reducing nicotine content decreases the addiction potential of smoking independent of sex in populations highly vulnerable to smoking and addiction, with no indication that women are less sensitive to subjective effects of RNCCs or would benefit less from a policy reducing the nicotine content of cigarettes.

Implications

A policy reducing the nicotine content of cigarettes has the potential to reduce the addiction potential of smoking across men and women who are especially vulnerable to smoking, addiction, and tobacco-related adverse health impacts.