Amygdala subnuclei resting-state functional connectivity sex and estrogen differences

Area of Science:

• Neuroscience
• Emotional Processing
• Sex Differences in Brain Function

Background:

• The amygdala plays a crucial role in processing emotions, particularly negative affect.
• Observed sex differences in the prevalence of fear, anxiety, and pain disorders may stem from distinct amygdala responses in men and women.

Purpose of the Study:

• To investigate sex differences in resting-state functional connectivity within amygdala subnuclei.
• To explore the relationship between amygdala functional connectivity and estrogen levels.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was used to measure connectivity.
• Functional connectivity was assessed using seed regions in the left and right laterobasal (LB) and centromedial (CM) amygdala.
• Participants included 48 healthy men and 48 healthy women, with hormone levels assessed in a subsample of 24 women.

Main Results:

• Distinct sex differences were identified in the resting-state functional connectivity of the LB and CM amygdala.
• Preliminary evidence suggests an association between estrogen levels and amygdala connectivity patterns.

Conclusions:

• These findings may help explain the higher prevalence of negative affect disorders in women compared to men.
• Estrogen may play a mechanistic role in modulating emotional processing via amygdala connectivity.