Brain size and shape in strongly and weakly lateralized mice

Area of Science:

• Neuroscience
• Behavioral Genetics
• Comparative Anatomy

Background:

• Cerebral lateralization, the preferential use of one brain hemisphere for a particular function, is a common trait in vertebrates.
• The relationship between the degree of lateralization and brain structure is not fully understood.
• Behavioral strategies may influence central nervous system development.

Purpose of the Study:

• To investigate the impact of differing degrees of lateralization on brain morphology in mice.
• To compare brain weight, cerebral asymmetry, and corpus callosum size across selected and control mouse lines.
• To explore potential links between behavioral strategies and central nervous system development.

Main Methods:

• Studied mice from two selected lines with marked differences in lateralization and a random-bred control line.
• Compared brain weight relative to body weight across the different mouse lines.
• Assessed the degree of cerebral asymmetry and measured the size of the corpora callosa.

Main Results:

• Mice with strong lateralization exhibited heavier brains, while those with weak lateralization had lighter brains compared to controls of equivalent body weight.
• The degree of cerebral asymmetry was least pronounced in the weakly lateralized mice.
• Both selected lines showed smaller corpora callosa compared to the control line.

Conclusions:

• Degree of brain lateralization is associated with significant differences in brain weight and structure.
• Behavioral strategies, as reflected by lateralization, may play a role in the developmental plasticity of the central nervous system.
• Findings suggest a complex interplay between behavior and neurodevelopmental trajectories.