Cerebellar network organization across the human menstrual cycle

Area of Science:

• Neuroscience
• Endocrinology
• Human Brain Imaging

Background:

• The cerebellum, rich in neurons, hosts functional networks and is a key site for sex steroid hormone action.
• Previous research has characterized cerebellar organization but not the impact of sex hormones on its intrinsic network dynamics.

Purpose of the Study:

• To investigate how endogenous estradiol and progesterone fluctuations alter resting-state functional cerebellar networks.
• To examine the relationship between sex hormones and cerebellar network dynamics across a complete menstrual cycle.

Main Methods:

• Utilized edgewise regression analysis to assess associations between hormones and cerebellar coherence.
• Employed graph theory metrics to analyze the influence of sex hormones on topological brain states.
• Monitored a woman over a 30-day menstrual cycle for dense sampling of hormonal and neural data.

Main Results:

• Found significant negative associations between progesterone levels and cerebellar coherence.
• Identified relationships between sex hormones and within-network integration in key cerebellar networks, including Ventral Attention, Dorsal Attention, and SomatoMotor Networks.

Conclusions:

• Endogenous fluctuations in sex steroid hormones dynamically influence the intrinsic functional organization of the cerebellum.
• Day-by-day changes in estradiol and progesterone are closely linked to the cerebellum's resting-state network dynamics.