April 14, 2017

Heather Bimonte-Nelson, Ph.D.

Heather Bimonte-Nelson, Ph.D.

Associate Professor, Department of Psychology

Arizona State University


Bio

Dr. Heather Bimonte-Nelson research goals are to characterize the cognitive and brain changes that occur during aging, as well as to develop behavioral, pharmacological, and dietary strategies to attenuate mnemonic and neurobiological age-related alterations using animal models. Towards this goal, one of her primary interests is to determine the roles that sex, hormones, and brain chemistry play in brain function and cognition in young versus aged animals. Her interests incorporate these goals with relevance to Alzheimer’s disease-related variables. To read more about Dr. Bimonte-Nelson, and the research she is working on, please go to http://psychology.clas.asu.edu/bimontenelson

Title of Grant Funded:
Cognitive function in a transitional versus surgical rat model of menopause
Grant Findings:
Our initial IMHR pilot grant evaluated whether surgical menopause initiated cognitive effects that differed from transitional menopause. It was only recently that cognitive effects of a transitional menopause model could be evaluated. Dr. Mayer and colleagues discovered that 4‐vinylcyclohexene diepoxide (VCD) results in ovarian follicular depletion in the rodent. In this rat model, after a gradual deterioration of follicles resulting in an ultimately extensive loss of follicular reserves, gonadal hormone and gonadotropin profiles are remarkably comparable to those of menopausal women. In our first IMHR grant in collaboration with Dr. Mayer, we found that transitional, gradual loss of ovarian hormones (induced via VCD) was better for cognition than abrupt ovarian hormone loss via surgical menopause. This transitional hormone loss benefited cognition only if the residual ovary was removed; this paper was recently published in Endocrinology (Acosta et al., 2009) and we have a second paper stemming from this work in review (we just submitted the revision in May, 2010) in Endocrinology as well. This is the top journal in the field, so we are thrilled that this research has been published into the journal. Of note, the initial IMHR VCD paper was also chosen as the top research finding in Endocrine Notes, 2009, by the Endocrine Society. In the brains of the animals receiving different menopause types from the initial paper, we examined the vesicular acetylcholine transporter (VAChT) since we previously found Premarin affected the basal forebrain cholinergic system (Acosta et al., 2009b). We found no treatment group differences in these hippocampal measurements.

Current Research Update: “Effects of menopause and hormone exposures on cognitive and brain health across the lifespan using preclinical modeling.”


How IMHR Helped Facilitate This Work: “IMHR gave my lab a running start, and I will forever be grateful. When my lab first started its research, the rodent model had been used to evaluate the cognitive and brain effects of ovarian hormone loss. The rat model had yielded much insight regarding the cognitive effects of surgical ovarian hormone loss. This ovarian hormone loss via surgical removal of the ovaries is an abrupt loss, and models about 13% of women. Most women undergo natural transitional menopause wherein ovarian follicular depletion occurs. While the question of the physiological and neurofunctional effects of a surgical abrupt versus transitional loss of ovarian hormones is important and clinically relevant, until the last decade basic science researchers did not have the means to evaluate the answer to this question since rats do not undergo ovarian follicular depletion. The discovery that 4-vinylcyclohexene diepoxide (VCD) induces loss of ovarian follicles allows animal researchers to evaluate the cognitive effects of non-surgically-induced ovarian hormone loss in the rat. Thus, we now have the capability to address this crucial question in an innovative way, using a model that accurately reflects the physiological presentation of transitional menopause in women. My IMHR grant was the first financial support I received to do this VCD model work studying cognition and the brain, collaborating with the developers of this model, Dr. Loretta Mayer and Dr. Cheryl Dyer. Since then, my collaborators, my students, and I have had nearly a dozen publications in this menopause/hormone area, and my R01 continuing this work has just been funded for years 11-15. This approximates about 5 million dollars in funding. The initial work from the IMHR grant allowed my team to develop the model and lay the foundation for my grant applications. In fact, Dr. Mayer and Dr. Dyer and my team still collaborate. This type of funding is a critical head start for a new investigator; not only did it give me financial support, it gave me confidence in my ideas. As a young principal investigator, this got me off running on an uphill trajectory. Thank you to IMHR!”