Sex-related Differences in Stress Reactivity and Cingulum White Matter

Area of Science:

• Neuroscience
• Psychology
• Neuroimaging

Background:

• The prefrontal cortex and limbic system are crucial for stress and anxiety regulation.
• White matter tracts, including the cingulum and fornix/stria terminalis, connect these regions.
• Understanding stress reactivity and white matter integrity may reveal factors of stress susceptibility and resilience.

Purpose of the Study:

• Investigate sex differences in the relationship between stress reactivity and white matter integrity.
• Examine generalized fractional anisotropy (GFA) in tracts connecting prefrontal cortex and limbic system.
• Explore associations between trait anxiety, stress response, and white matter structure.

Main Methods:

• Diffusion weighted imaging and deterministic tractography in 104 young adults.
• Salivary cortisol measurements before, during, and after the Trier Social Stress Test.
• Self-report questionnaires assessing trait anxiety.

Main Results:

• Sex differences observed in cortisol reactivity and cingulum bundle GFA.
• Men exhibited greater cortisol reactivity and higher cingulum GFA than women.
• A significant interaction revealed sex-specific relationships between cingulum GFA and cortisol reactivity; trait anxiety positively correlated with fornix/stria terminalis GFA.

Conclusions:

• Sex influences the relationship between white matter integrity and stress reactivity.
• The cingulum bundle's GFA and its association with cortisol response differ between men and women.
• White matter pathways, particularly the fornix/stria terminalis, are associated with trait anxiety, offering insights into individual stress differences.