Sex hormone mediated change on flexion reflex

Area of Science:

• Neuroscience
• Endocrinology
• Motor Control

Background:

• Estrogen and progesterone receptors are present in the spinal cord.
• Hormonal fluctuations during the menstrual cycle may impact motor control.
• The polysynaptic spinal network's role in movement modulation requires further investigation.

Purpose of the Study:

• To investigate the neuro-modulatory effects of sex hormones on the spinal network.
• To examine how estradiol and progesterone influence the flexion reflex in women.
• To correlate hormone levels with specific parameters of spinal reflex activity.

Main Methods:

• Studied 24 healthy women across one menstrual cycle.
• Measured serum estradiol and progesterone levels.
• Assessed the tibialis anterior flexion reflex via electrical nerve stimulation.
• Analyzed data based on menstrual cycle phases (follicular and luteal).

Main Results:

• No significant association between estradiol/progesterone and reflex duration or amplitude.
• Increased estradiol in the luteal phase correlated with longer reflex latency (p=0.038).
• A trend towards significance was observed for the estradiol × progesterone interaction (p=0.081).

Conclusions:

• Estradiol may modulate spinal reflex latency, particularly in the luteal phase.
• Evidence suggests a potential synergistic effect of estradiol and progesterone on motor control.
• These findings support the modulatory role of sex hormones in spinal cord function.