Sandra Reichel

Training in laboratory animals is important to ensure that scientific studies are reliable, reproducible, and ethically acceptable. Well-trained animals experience less stress and exhibit fewer unwanted behaviors, improving both welfare and research outcomes. Clicker training is widely used in animal training as a positive reinforcement method to reduce distress. The present study was designed as a pilot study to examine the effects of a four-day clicker training protocol applied to both dams and their offspring, with behavioral outcomes assessed exclusively in the offspring. The results indicated that clicker training potentially increased voluntary interaction with the experimenter and promoted body weight gain during the training period. No significant effects of offspring training were found for classical anxiety-related measures (EPM open arm time, OF center time, Nest Building Test, Sucrose Preference Test, Forced Swim Test) or plasma corticosterone. A potential sex effect was observed across locomotor, center-zone, and corticosterone measures. Maternal training effects on offspring outcomes should be interpreted as preliminary exploratory observations, as only two dams per maternal group were available. Given the exploratory nature and limited sample size of this pilot study, the findings should be interpreted with caution. Under the present condition, clicker training produced a context-specific improvement in human–animal interaction without evidence of harm, but did not produce generalized reductions in anxiety-like behaviors as assessed by standard paradigms. Further studies with larger sample sizes are needed to confirm these findings.

Improving laboratory animal welfare by minimizing stress and promoting species-appropriate handling is a central goal of contemporary biomedical research worldwide. Clicker training, a widely recognized form of positive reinforcement training, uses a click sound as a conditioned reinforcer to bridge the desired behavior and the reward, enabling animals to learn more quickly and with reduced stress. Our research group has previously demonstrated that clicker training functions as a form of cognitive enrichment in mice and rats. In the present study, we successfully adapted this training approach for Mongolian gerbils (Meriones unguiculatus), tailoring the protocol to the species-specific behavioral characteristics of gerbils. A cohort of 43 inbred gerbils (27 females and 16 males) underwent a standardized 10-day clicker training protocol, during which they learned to voluntarily approach and interact with the experimenter's hand in exchange for a food reward. Following the training period, animals were subjected to behavioral assessments, including an Open Field Test and a standardized human interaction test, to evaluate the effects of training on exploratory behavior and human-animal interaction. Our findings demonstrate that the implementation of clicker training in gerbils is fast, efficient, and well-tolerated. Trained animals, particularly females, showed increased voluntary interaction with the experimenter's hand and reduced anxiety-like behaviors. These results suggest that species-adapted clicker training protocols can facilitate the development of trust between experimenter and animal, ultimately decreasing stress and improving both animal welfare and the reliability of experimental outcomes.

Improving laboratory animal welfare by minimizing stress and promoting species-appropriate handling is a central goal of contemporary biomedical research worldwide. Clicker training, a widely recognized form of positive reinforcement training, uses a click sound as a conditioned reinforcer to bridge the desired behavior and the reward, enabling animals to learn more quickly and with reduced stress. Our research group has previously demonstrated that clicker training functions as a form of cognitive enrichment in mice and rats. In the present study, we successfully adapted this training approach for Mongolian gerbils (Meriones unguiculatus), tailoring the protocol to the species-specific behavioral characteristics of gerbils. A cohort of 43 inbred gerbils (27 females and 16 males) underwent a standardized 10-day clicker training protocol, during which they learned to voluntarily approach and interact with the experimenter's hand in exchange for a food reward. Following the training period, animals were subjected to behavioral assessments, including an Open Field Test and a standardized human interaction test, to evaluate the effects of training on exploratory behavior and human-animal interaction. Our findings demonstrate that the implementation of clicker training in gerbils is fast, efficient, and well-tolerated. Trained animals, particularly females, showed increased voluntary interaction with the experimenter's hand and reduced anxiety-like behaviors. These results suggest that species-adapted clicker training protocols can facilitate the development of trust between experimenter and animal, ultimately decreasing stress and improving both animal welfare and the reliability of experimental outcomes.

The CatWalk test relies on the run of mice across the platform to measure a constant speed with low variation. Mice usually require a stimulus to walk to the end of the catwalk. However, such stimuli are usually aversive and can impair welfare. Positive reinforcement training of laboratory animals is a thriving tool for refinement and contributes to meeting the demands instituted by Directive 2010/63/EU. We have already demonstrated the positive effects of clicker training. In this study, we trained male and female mice to complete the CatWalk protocol while assessing the effects of training on their well-being (Open Filed and Elevated Plus Maze). In the CatWalk test, we observed that clicker training improved the running speed of the mice. In addition, clicker training reduced the number of runs required by mice, which was more pronounced in males. Clicker training lowered anxiety-like behaviors in our mice, especially in females, where a significant difference was observed between trained and untrained ones. Based on our findings, we hypothesize that clicker training is an effective tool to motivate mice and increase performance on the CatWalk test without potentially impairing their welfare (e.g., by puffing them).