Mij
Senior Member (Voting Rights)
Abstract
Males and females experience different trajectories of neuromuscular function across the lifespan, with females demonstrating accelerated deconditioning in later life. We hypothesize that the menopause is a critical period in the female lifespan, during which the dramatic reduction in sex hormone concentrations negatively impacts synaptic input to the motoneuron pool, as well as motor unit discharge properties.
KEY POINTS
Males and females experience different trajectories of neuromuscular function across the lifespan, with females demonstrating accelerated deconditioning in later life. We hypothesize that the menopause is a critical period in the female lifespan, during which the dramatic reduction in sex hormone concentrations negatively impacts synaptic input to the motoneuron pool, as well as motor unit discharge properties.
KEY POINTS
- Sex hormones influence central nervous system properties, with either neuroexcitatory or inhibitory actions.
- Premenopausal, eumenorrheic females experience cyclical changes in the neural excitation/inhibition balance across the menstrual cycle. This affects the firing rates of motor units that control muscle contraction.
- Females exhibit an exaggerated decline of neuromuscular function in later life, which may be a consequence of the drastic reduction in sex hormone concentrations following the menopausal transition.
- This review proposes the hypothesis that the rate of neuromuscular aging is accelerated by the menopause in females, whereas males demonstrate a more gradual decline. This is potentially a contributing factor to the health-survival paradox whereby females live longer than males yet spend greater time in poor health.