PLP1 Gene Variation Modulates Leftward and Rightward Functional Hemispheric Asymmetries

Area of Science:

• Neurobiology
• Genetics
• Cognitive Neuroscience

Background:

• Corpus callosum structure and function are linked to hemispheric asymmetries.
• Myelin-related genes, including PLP1 and CNTN1, have been associated with interhemispheric integration differences.

Purpose of the Study:

• To investigate if specific single nucleotide polymorphisms (SNPs) in PLP1 and CNTN1 are relevant for functional hemispheric asymmetries.
• To examine the association between these genetic variations and performance in tasks assessing language lateralization and spatial attention.

Main Methods:

• Tested over 900 healthy adults using the forced attention dichotic listening task for language lateralization.
• Employed the line bisection task to assess spatial attention asymmetries.
• Analyzed the association between specific SNPs and task performance.

Main Results:

• A polymorphism in the PLP1 gene, but not CNTN1, was significantly associated with performance differences in both the dichotic listening and line bisection tasks.
• Functional hemispheric asymmetries and their modulation by cognitive control processes were affected by the PLP1 polymorphism.

Conclusions:

• Allelic variations in genes affecting corpus callosum structure, such as PLP1, can modulate cognitive functions lateralized to either the left or right hemisphere.
• Higher-order cognitive processes are important parameters for understanding the molecular basis of hemispheric asymmetries.