The effect of hormones on cognitive abilities has been thoroughly examined, demonstrating that a broad range of variables can significantly impact memory. Estrogen-containing hormone treatment is still a common therapeutic strategy for menopausal symptoms. Substantial variations and ultimate declines in innately circulating female hormones, particularly estrogens, around midlife with biological menopausal beginning or with surgical menopause often cause unpleasant physical consequences, causing either pain or constant discomfort. The current study evaluated the impact of 17-estradiol administration in ovariectomized female rats for seven months, starting in late maturity and extending until midlife. Ultimately, the findings of the research indicate that 7-estradiol treatment can have some long-term cognitive advantages.
In the beginning, the researchers emphasize that only a limited number of research has carefully studied the cognitive consequences of long-term sustained 17-estradiol treatment while also estimating the changes in circulating the given hormone throughout the menopausal transition. While older hormone therapy research revealed the harmful effects of such treatment, including cardiovascular disease risk and cognitive risks, recent studies indicated that more variables need to be incorporated (Koebele et al., 2020). Considering that many women choose estrogen-containing hormone treatment throughout the transitioning stage to menopause or after surgically occurring menopause, it is essential to comprehend the brain functions and general health impacts of continuous exposure to 17-estradiol.
Following the set objective to determine the impact of hormone exposure is critical, the researchers chose 30 rats as subjects of the study. As a result, the hormone was administered bimonthly to adult rats (Koebele et al., 2020). Rodents were evaluated six months after chronic administration on a series of cognitive tests assessing brain functioning, spatial reference memory, conduct, exploration tendency, and motor function (Koebele et al., 2020). Ultimately, the researchers discovered that a 17-estradiol injection strategy improved cognitive performance when memory capacity was challenged, enhanced object exploration, and reduced nervousness as compared to rats with short-term therapy.
Regarding the specific tasks, rodents were assessed on various activities and cognition settings, including water maze tests and exploration tasks. In the first example, all rats performed the assignment well, with no therapy group differences (Koebele et al., 2020). Nevertheless, the inability of the majority of rodents to examine the items was a startling result. Yet, there is a plausible reason for the reduced proclivity to investigate items (Koebele et al., 2020). The researchers discovered that the significance of the incentive to seek novelty is rarely discussed when analyzing the results of studies utilizing elderly animals in the experiment (Koebele et al., 2020). Some data suggest that the desire to undertake object identification tasks diminishes with aging.
Hence, many women struggle with menopausal changes that are either biologically or surgically induced. Consequently, there is a necessity for continuous exposure to hormone therapy. The given research used 30 adult female rodents to investigate the effects of long-term exposure to 17-estradiol administration. While most rodents performed most of the tasks successfully, they still failed at object investigation tasks. Nevertheless, considering the animal propensity to experience lower interest in such tasks at this age, these results do not have an immense impact on the findings. Thus, the findings of the given research support the notion that, under suitable conditions, long-term constant exposure to 17-estradiol therapy has the potential to lead to favorable cognitive results.
Reference
Koebele, S. V., Nishimura, K. J., Bimonte-Nelson, H. A., Kemmou, S., Ortiz, J. B., Judd, J. M., & Conrad, C. D. (2020). A long-term cyclic plus tonic regimen of 17β-estradiol improves the ability to handle a high spatial working memory load in ovariectomized middle-aged female rats. Hormones and Behavior, 118, 104656.