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A test to identify judgement bias in mice
Hetty Boleij1, José van't Klooster, Marla Lavrijsen
1Department of Animals in Science and Society, Division of Animal Welfare and Laboratory Animal Science, Utrecht University, Utrecht, The Netherlands. h.boleij@uu.nl
Behavioural Brain Research
|May 8, 2012
Summary
This study developed a judgment bias test for mice to assess emotional states. BALB/cJ mice, showing higher anxiety, interpreted ambiguous cues negatively, unlike 129P3/J mice, suggesting potential for animal emotional state assessment.
Area of Science:
- Animal behavior
- Neuroscience
- Cognitive psychology
Background:
- Emotional states influence cognitive processes, including how individuals interpret ambiguous stimuli.
- A negative judgment bias, where ambiguous cues are perceived negatively, is linked to higher anxiety.
- Measuring judgment bias is being explored as a method to indicate emotional states in animals.
Purpose of the Study:
- To examine a potential judgment bias test for assessing emotional states in mice.
- To investigate differences in judgment bias between high and low anxiety mouse strains.
- To explore the neural correlates of judgment bias in mice.
Main Methods:
- Mice were trained using distinct odor cues (vanilla, apple) predicting palatable or unpalatable rewards.
- Reactions to ambiguous stimuli (odor mixtures) were assessed in BALB/cJ (high anxiety) and 129P3/J (low anxiety) mouse strains.
- Brain c-Fos expression was measured in key brain regions, and behavioral responses under different light conditions were recorded.
Main Results:
- BALB/cJ mice demonstrated odor association learning and intermediate reactions to ambiguous cues, while 129P3/J mice did not discriminate.
- BALB/cJ mice exhibited longer latencies to approach rewards under aversive white light compared to red light.
- Both light conditions led BALB/cJ mice to interpret ambiguous stimuli negatively.
- Differential c-Fos expression in the lateral amygdala and prelimbic cortex was observed between strains, indicating distinct processing of ambiguous information.
Conclusions:
- The developed judgment bias test shows potential for assessing emotional states, particularly in BALB/c mice.
- Behavioral and neural differences highlight strain-specific processing of ambiguous stimuli.
- Further research is needed to validate the test and elucidate underlying brain mechanisms.
