Sympathetic nervous system control across the menstrual cycle

Area of Science:

• Cardiovascular Physiology
• Neuroendocrinology
• Autonomic Neuroscience

Background:

• The menstrual cycle involves hormonal fluctuations affecting physiological systems, including cardiovascular control.
• The sympathetic nervous system regulates cardiovascular homeostasis via hemodynamics, neural reflexes, and neurovascular transduction.
• The impact of endogenous hormonal shifts on autonomic pathways is not well understood.

Purpose of the Study:

• To review current evidence on autonomic function throughout the menstrual cycle.
• To examine muscle sympathetic nerve activity, sympathetic neurovascular transduction, neural reflexes, and heart rate variability.
• To explore the influence of exogenous hormones on autonomic regulation.

Main Methods:

• Narrative review of existing literature.
• Focus on autonomic function across different menstrual cycle phases.
• Inclusion of studies on muscle sympathetic nerve activity, neurovascular transduction, neural reflexes, and heart rate variability.

Main Results:

• Resting sympathetic drive is elevated in the mid-luteal phase.
• Most neural reflexes remain stable, suggesting estradiol buffers increased sympathetic drive.
• The peripheral chemoreflex is an exception to this reflex stability.

Conclusions:

• Estradiol surge in the mid-luteal phase enhances sympatholysis and nitric oxide bioavailability.
• Autonomic pathways show phase-dependent modulation during the menstrual cycle.
• Understanding these interactions is crucial for female lifespan physiology and pathophysiology.