# Variations in Hormones During Menopause: Effects on Cognitive and Brain Aging

> **NIH NIH R01** · ARIZONA STATE UNIVERSITY-TEMPE CAMPUS · 2020 · $319,849

## Abstract

The broad goal of our continued program of research is to decipher the cognitive and brain effects of transitional
and surgical variants of menopause, including optimizing cognitive aging by discovering efficacious hormone
therapy (HT) options in the context of menopause variations seen in women. This incorporates determining
memory and brain changes as transitional menopause ensues when ovaries are undergoing follicular depletion,
as well as the optimal parameters for interventions subsequent to transitional and surgical menopause variants.
Menopause has been associated with cognitive decline and increased dementia risk. However, factors driving
these outcomes, and which HT parameters alter effects, are undetermined. Importance is underscored given
that most women are living at least one-third of their lives in a menopausal state encompassed by numerous
variations (with or without a uterus, follicular deplete ovaries, or HT). In the current grant period, we had 23
publications; using the rat model, we showed that transitional menopause detrimentally impacted memory, that
effects were most pronounced during perimenopause when follicles were undergoing early depletion, that higher
androstenedione levels were associated with worse memory outcomes, and that short-term hysterectomy (uterus
removal) alone impaired memory. We found that progesterone impaired memory, and that these effects were
modulated by the GABAergic system. We also showed that several clinically-used synthetic progestins impaired
memory, and identified one that enhanced memory: Levonorgestrel (Levo). When taking oral contraceptives or
HT, a woman with a uterus must include a progestin along with estrogens to offset estrogen-induced hyperplasia.
Thus, we performed an individual versus combination study, and showed that 17β-estradiol (E2) and Levo each
enhanced memory when given alone, but impaired memory when given in combination. We also found that E2-
induced cognitive benefits were associated with cholinergic integrity, building on literature showing estrogen-
cholinergic interactions. This renewal addresses critical questions stemming from these collective findings. Aim
1 tests whether varied E2 regimens attenuate memory impairments associated with the perimenopausal
transition, and assesses novel progestins that are anti-androgenic or have minimal androgenicity, with a goal to
find options that do not reverse beneficial E2 effects on cognition and the brain. Aim 2 determines how variations
in menopause type, including hysterectomy, impact cognition and the brain, testing effects of a temporal window,
age, and follicular depletion state. Aim 3 defines how menopause variants and clinically-used HTs interact with
candidate neurotransmitter systems in mechanistic detail, systematically examining GABAergic signaling and
cholinergic circuitry. We combine behavioral, physiological, and neurobiological approaches in the framework of
a blinded and randomized animal model research progra...

## Key facts

- **NIH application ID:** 9936098
- **Project number:** 5R01AG028084-13
- **Recipient organization:** ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
- **Principal Investigator:** HEATHER Allyson BIMONTE-NELSON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $319,849
- **Award type:** 5
- **Project period:** 2007-09-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9936098

## Citation

> US National Institutes of Health, RePORTER application 9936098, Variations in Hormones During Menopause: Effects on Cognitive and Brain Aging (5R01AG028084-13). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9936098. Licensed CC0.

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