Changes in brain architecture are consistent with altered fear processing in domestic rabbits

Area of Science:

• Neuroscience
• Animal Behavior
• Comparative Anatomy

Background:

• Behavioral changes, particularly tameness, are hallmarks of animal domestication.
• Understanding the neurobiological underpinnings of these behavioral shifts is crucial for comprehending domestication's impact.

Purpose of the Study:

• To investigate the structural brain differences between wild and domestic rabbits.
• To correlate observed brain alterations with behavioral changes associated with domestication, specifically tameness and fear response.

Main Methods:

• High-resolution magnetic resonance imaging (MRI) was employed to compare brain structures.
• Analysis focused on gray matter volumes (amygdala, medial prefrontal cortex) and white matter integrity (anisotropy in specific tracts).

Main Results:

• Domestic rabbits exhibited reduced amygdala volume (fear processing) and enlarged medial prefrontal cortex volume (negative affect modulation).
• White matter anisotropy was decreased in the corona radiata, corpus callosum, and subcortical regions, indicating compromised structural integrity.
• These findings suggest altered neural processing and connectivity in domestic rabbits.

Conclusions:

• Domestication-induced changes in brain architecture, including gray and white matter alterations, are linked to reduced fear and attenuated flight responses in domestic rabbits.
• The study provides neuroanatomical evidence supporting the behavioral modifications observed during the domestication process.