Progesterone mediates brain functional connectivity changes during the menstrual cycle-a pilot resting state MRI...

Area of Science:

• Neuroscience
• Endocrinology
• Human Brain Mapping

Background:

• Growing interest in intrinsic brain organization and connectivity mapping.
• Known sexual dimorphism in the human connectome.
• Uncertainty regarding menstrual cycle hormonal impact on female brain function.

Purpose of the Study:

• To investigate if menstrual cycle hormonal fluctuations affect the functional architecture of the female brain.
• To assess associations between cycle-dependent hormones (estrogen, progesterone) and brain connectivity.

Main Methods:

• Longitudinal resting-state functional Magnetic Resonance Imaging (rs-fMRI) in a single healthy subject across four menstrual cycles.
• Eigenvector centrality (EC) mapping to analyze functional brain connectivity.
• Correlation analyses between EC maps and measured hormone levels.

Main Results:

• Significant positive correlation found between progesterone levels and EC in the bilateral dorsolateral prefrontal cortex (DLPFC) and sensorimotor cortex.
• Progesterone modulated an increase in functional connectivity between the bilateral DLPFC, sensorimotor cortex, and the hippocampus.
• Menstrual cycle phase substantially impacts intrinsic functional connectivity, especially in memory-related brain areas.

Conclusions:

• Subtle hormonal fluctuations during the menstrual cycle significantly alter regional functional connectivity, particularly involving the hippocampus.
• Findings demonstrate the impact of the menstrual cycle on intrinsic functional connectivity in the female brain.
• Highlights the feasibility of longitudinal rs-fMRI for personalized brain mapping, integrating hormonal mediators.