Related Experiment Videos
Individual variability in cortical organization: its relationship to brain laterality and implications to function
A M Galaburda1, G D Rosen, G F Sherman
1Dyslexia Research Laboratory, Beth Israel Hospital, Boston, MA.
Neuropsychologia
|January 1, 1990
Summary
Brain asymmetry varies between individuals and species. Greater asymmetry correlates with fewer neurons and altered brain connections, potentially explaining differences in language function.
Area of Science:
- Neuroscience
- Comparative Anatomy
- Brain Evolution
Background:
- Mammalian brains exhibit hemispheric asymmetry in structure.
- Individual and species-level variations in asymmetry exist.
- Asymmetry patterns can show population-level biases.
Purpose of the Study:
- To investigate the relationship between cortical asymmetry and neuronal numbers.
- To explore the link between asymmetry and interhemispheric/intrahemispheric connections.
- To understand how these factors influence developmental processes and anatomo-clinical correlations.
Main Methods:
- Comparative analysis of gross anatomical landmarks and cortical architectonics across species.
- Correlation studies examining asymmetry magnitude with neuronal counts and connection densities.
- Developmental analysis focusing on cell loss and axonal pruning in asymmetric regions.
Main Results:
- Higher cortical asymmetry predicts fewer neurons in homologous regions.
- Increased asymmetry is associated with reduced interhemispheric connections.
- Diminished neuronal numbers in asymmetric regions likely result from increased cell loss during development.
Conclusions:
- Cortical asymmetry influences neuronal population size and connectivity patterns.
- Developmental processes like cell loss and axonal pruning underlie these relationships.
- Asymmetry-related neural variations may explain individual differences in language function and aphasia.