The effects of estrogens on brain plasticity

Abstract

Introduction: • Estrogens have efects not only on gonads but also on the hippocampus and the prefrontal cortex area. • The fluctuations of estrogen levels directly influence cognitive functions, an important point in menopause management. Purpose: To study the importance of estrogens in neuroprotection and the effectiveness of hormonal therapy depending on the age, type (natural/ induced) and stage (early/ late) of the menopause. Material and methods: This is the synthesis of 20 medical research articles published in the period of 2014-2019, found with the research motors PubMed, NCBI and Sciencedirect. Results: • Clinical studies have proved that estrogens mediated effects are a result of interaction with the receptors ERα, ERβ and GPER1 from the neurons of the hippocampus and prefrontal cortex. • Estrogens mediate: the dendritic density growth thus helping the formation of new synapses, stimulating the glycolytic over ketogenic metabolism, maintaining Ca⁺ homeostasis. These effects are important for the optimal functioning of the memory and for the reduction of neurodegenerative processes. • The lower levels of circulating estrogens during menopause can cause: memory alterations, neural hypometabolism, risk of developing dementia. Conclusions: Hormone replacement therapy for the promotion of neuroprotection shows eficacy depending on the time of administration and reported to the natural or surgical menopause onset.