Estrogen replacement therapy induces functional asymmetry on an odor memory/discrimination test

Area of Science:

• Neuroscience
• Endocrinology
• Sensory Perception

Background:

• Olfactory system pathways project ipsilaterally, making unilateral testing valuable for assessing hemispheric activity.
• Estrogen's influence on lateralized perceptual task performance is documented.
• Menopause and hormone replacement therapy (HRT) provide a model for studying hormonal effects on sensory processing.

Purpose of the Study:

• To investigate the effects of estrogen replacement therapy (ERT) on olfactory function lateralization in post-menopausal women.
• To compare olfactory performance differences between the left and right nostrils in women on ERT versus those not on ERT.

Main Methods:

• Assessed left:right nostril differences in olfactory function using two tests: odor memory/discrimination and odor detection threshold.
• Studied 14 post-menopausal women on ERT and 48 post-menopausal women not on ERT.

Main Results:

• Women receiving ERT showed improved left nostril performance and reduced right nostril performance on an odor memory/discrimination test compared to women not on ERT.
• No significant laterality effects were observed for the odor detection threshold test.

Conclusions:

• Estrogen appears to influence the lateralization of olfactory memory and discrimination.
• Hormone replacement therapy during menopause is a relevant model for understanding how hormones affect sensory lateralization.