Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions.

Mice are the most commonly used laboratory animal, yet there are limited studies which investigate the effects of repeated handling on their welfare and scientific outcomes. Furthermore, simple methods to evaluate distress in mice are lacking, and specialized behavioral or biochemical tests are often required. Here, two groups of CD1 mice were exposed to either traditional laboratory handling methods or a training protocol with cup lifting for 3 and 5 weeks. The training protocol was designed to habituate the mice to the procedures involved in subcutaneous injection, e.g., removal from the cage, skin pinch. This protocol was followed by two common research procedures: subcutaneous injection and tail vein blood sampling. Two training sessions and the procedures (subcutaneous injection and blood sampling) were video recorded. The mouse facial expressions were then scored, focusing on the ear and eye categories of the mouse grimace scale. Using this assessment method, trained mice expressed less distress than the control mice during subcutaneous injection. Mice trained for subcutaneous injection also had reduced facial scores during blood sampling. We found a clear sex difference as female mice responded to training faster than the male mice, they also had lower facial scores than the male mice when trained. The ear score appeared to be a more sensitive measure of distress than the eye score, which may be more indicative of pain. In conclusion, training is an important refinement method to reduce distress in mice during common laboratory procedures and this can best be assessed using the ear score of the mouse grimace scale.

Training pair-housed Rhesus macaques (Macaca mulatta) using a combination of negative and positive reinforcement.

When training animals, time is sometimes a limiting factor hampering the use of positive reinforcement training (PRT) exclusively. The aim of this study was to evaluate the effects of a combination of negative and positive reinforcement training (NPRT). Twenty naïve female Rhesus macaques (Macaca mulatta) were trained in 30 sessions with either PRT (n=8) or NPRT (n=12) to respond to a signal, move into a selected cage section and accept confinement. In the NPRT-group a signal preceded the presentation of one or several novel, and thus aversive, stimuli. When the correct behaviour was performed, the novel stimulus was removed and treats were given. As the animal learned to perform the correct behaviour, the use of novel stimuli was decreased and finally phased out completely. None of the PRT-trained animals finished the task. Ten out of 12 monkeys in the NPRT-group succeeded to perform the task within the 30 training sessions, a significant difference from the PRT-group (p=0.0007). A modified approach test showed no significant difference between the groups (p=0.67) in how they reacted to the trainer. The results from this study suggest that carefully conducted NPRT can be an alternative training method to consider, especially when under a time constraint.

Can conditioned reinforcers and Variable-Ratio Schedules make food- and fluid control redundant? A comment on the NC3Rs Working Group's report.

This commentary challenges the conclusions of the NC3Rs Working Group's recent special report that food- or fluid control is sometimes necessary to conduct modern neuroscientific investigations in macaque monkeys (Prescott et al., 2010). Given the potential suffering of animals subjected to food- or fluid control, the decision to subject an animal to such practices should be taken hesitantly. That decision hinges on to which extent the animal is willing to be involved in the task. The authors have done a scientific literature search and express expert opinion, but fail to mention two techniques that may greatly influence the animals' motivation to participate in the task and thus reduce the need for food- or fluid control, namely (1) the use of conditioned reinforcers in addition to primary reinforcers; and (2) the use of Variable-Ratio Schedules rather than continuous reinforcement. An ethical and humane approach to animal experimentation suggests that all options should be explored and thoroughly investigated before resorting to methods potentially challenging the animals' welfare.

Aggression and withdrawal related behavior within conflict management progression in preschool boys with language impairment.

OBJECTIVE: This study examined conflict behavior in naturalistic preschool settings to better understand the role of non-affiliative behavior and language in conflict management. METHOD: Free-play at preschool was filmed among 20 boys with typically developing language (TL) and among 11 boys with Language Impairment (LI); the boys 4-7 years old. Conflict behavior was coded and analyzed with a validated system. Post-conflict non-affiliative behavior (aggression and withdrawal) displays, and the links between the displays and reconciliation (i.e., former opponents exchange friendly behavioral shortly after conflict termination) was examined. RESULTS: Group comparisons revealed boys with LI displayed aggression in a smaller share of conflicts, but exhibited [Symbol: see text]active' withdrawal (left the room), in a larger conflict share. Boys with TL overcame aggression (more common TL behavior) and after reconciled, to a greater extent than the boys with LI after active withdrawal (more common LI behavior). Also, after reciprocal or only verbal aggression, boys with LI reconciled to a lesser extent than boys with TL. CONCLUSIONS: The boys with LI demonstrated difficulties confronting conflict management, as well as concluding emotionally heightened and aggressive behavioral turns.

Impaired reconciliation in rhesus macaques with a history of early weaning and disturbed socialization.

An attempt had been made to create five social groups from rhesus macaques with a history of early separation from their mothers, early weaning and hand feeding and, in most cases, previous housing in single cages. We investigated the exchange of affiliative behaviours after an aggressive encounter and selective attraction to the former opponent, a phenomenon previously well described in rhesus monkeys and called reconciliation. Evidence for reconciliation was only found in one of the five groups studied (corrected conciliatory tendency=13%). This group consisted of younger animals that had, at least temporarily, been living together after separation from their mothers. In the other groups studied, containing animals with a varied background, aggressive interactions were not followed by affiliative behaviours or attraction between former opponents. Our results indicate that the use of reconciliatory behaviours in adult monkeys is dependent upon social training. Lack of functional reconciliation might be one of the explanations to the severe and uncontrolled aggression previously found in groups of rhesus macaques created from animals with disturbed early socialization.