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Stimulus generalization and return of fear in C57BL/6J mice
Yannick Boddez1, Zsuzsanna Callaerts-Vegh, Bram Vervliet
1Department of Psychology, KU Leuven Leuven, Belgium.
Abstract:
Return of fear following successful exposure therapy is a common problem. More insight into the characteristics of extinction learning is crucial in enhancing the efficiency of therapeutic interventions. In particular, understanding the mechanisms that underlie the generalization of extinction learning to other discrete stimuli is indispensable. Presently, little is known about the molecular and genetic mechanisms underlying this phenomenon. In this study, we attempt to develop a new conditioning protocol to study return of fear, caused by a stimulus change after extinction, in the most commonly used mouse strain of behavioral genetics, C57BL/6J. Perceptual changes to an auditory fear conditioned stimulus led to return of fear after initially successful fear-reduction, relative to appropriate control treatment. We argue that this protocol will be a useful tool to unravel the neurobiological underpinnings that regulate generalization of extinction and return of fear. Key questions for future research include the identification of crucial brain structures, neurotransmitters and signaling pathways that underly this behavioral phenomenon. Arguably, such research will open up new perspectives for neurobiological therapy augmentation.
Insights
Return of fear after therapy can be reduced by understanding extinction learning generalization. This study introduces a new mouse model to investigate the neurobiology of fear relapse and improve therapeutic interventions.
Area of Science:
- Neuroscience
- Behavioral Genetics
- Psychology
Background:
- Relapse of fear after successful exposure therapy is a significant clinical challenge.
- Understanding extinction learning, particularly stimulus generalization, is vital for improving therapeutic outcomes.
- The molecular and genetic mechanisms driving fear generalization and relapse remain largely unexplored.
Purpose of the Study:
- To develop a novel conditioning protocol for studying the return of fear in C57BL/6J mice.
- To investigate the impact of perceptual changes in a conditioned stimulus on fear relapse after extinction.
- To provide a tool for uncovering the neurobiological basis of extinction generalization and fear return.
Main Methods:
- Development of a new auditory fear conditioning and extinction protocol in C57BL/6J mice.
- Introduction of perceptual changes to the conditioned stimulus post-extinction.
- Comparison of fear responses in experimental groups versus appropriate control groups.
Main Results:
- Perceptual changes to the auditory conditioned stimulus induced a return of fear.
- This effect was observed even after initially successful fear reduction through extinction.
- The protocol demonstrated efficacy in eliciting fear relapse under controlled conditions.
Conclusions:
- The developed protocol effectively models the return of fear due to stimulus change after extinction.
- This model serves as a valuable tool for investigating the neurobiological mechanisms of extinction generalization.
- Future research using this model can identify key brain structures, neurotransmitters, and pathways, paving the way for enhanced therapeutic strategies.
