Featured Research

from universities, journals, and other organizations

Estrogen Deprivation Leads To Death Of Dopamine Cells In The Brain

Date:
December 5, 2000
Source:
Yale University
Summary:
Estrogen deprivation leads to the death of dopamine cells in the brain, a finding by Yale researchers that could have implications for post-menopausal women. The cells can be regenerated if estrogen is administered within 10 days, but by 30 days, the cells appear to be permanently lost, said D. Eugene Redmond, Jr., professor of psychiatry and neurosurgery at Yale School of Medicine and director of the Neural Transplantation and Regeneration Program.

Estrogen deprivation leads to the death of dopamine cells in the brain, a finding by Yale researchers that could have implications for post-menopausal women.

The cells can be regenerated if estrogen is administered within 10 days, but by 30 days, the cells appear to be permanently lost, said D. Eugene Redmond, Jr., professor of psychiatry and neurosurgery at Yale School of Medicine and director of the Neural Transplantation and Regeneration Program. Redmond is co-investigator and spokesperson about the study published in the December issue of The Journal of Neuroscience.

The principal investigator was Csaba Leranth, M.D., professor of obstetrics and gynecology and neurobiology.

"Without estrogen, more than 30 percent of all the dopamine neurons disappeared in a major area of the brain that produces the neurotransmitter, dopamine, " Redmond said. "This finding is consistent with a lot of observations for which there has been, until now, no explanation. The results of the study shed light on why men, who have less estrogen in their bodies and more androgen to antagonize it, are more likely to develop Parkinson's Disease than pre-menopausal women, and why post menopausal women are more likely then to develop the disease."

The discovery was made after the researchers removed the ovaries of female monkeys, thereby depleting their bodies of estrogen and other gonadal hormones. Within 10 days, key neurons in the brain that protect against Parkinson's Disease disappeared.

Redmond said monkeys were used in the study because, unlike usual laboratory animals, they have real menstrual cycles and many other close similarities to humans. The researchers were interested in sexual differences in dopamine neurons in the substantia nigra area of the midbrain, whose destruction is associated with Parkinson's Disease and dementia.

The researchers first sought to determine whether circulating estrogen might have long term effects by altering the number of dopamine neurons. The density of dopamine neurons was calculated in the substantia nigra of intact male and female primates; in female primates whose ovaries had been removed; and in female primates whose ovaries had been removed but were receiving estrogen replacement therapy.

"After both 10 and 30 days of estrogen deprivation, apparently 30 percent of the total number of substantia nigra dopamine cells are lost," Redmond said. "Furthermore, the density calculations showed that brief estrogen replacement restores the density of the total number of neurons in that area of the brain 10 days after the ovaries have been removed, but not 30 days later."

"These observations show the essential role of estrogen in maintaining the integrity of the nigral dopamine system involved in muscle control and higher brain functions. It suggests a new prevention or treatment strategy for patients at risk of Parkinson's disease and certain forms of memory-impairing disorders,"he said. "This also provides another rationale for estrogen replacement therapy for postmenopausal women. Thirty percent is a very significant number of cells in this system. Maintenance, restoration, or loss of that many cells could make the difference between severe parkinsonism and having no symptoms at all."

But Redmond cautioned that women should not use the results to make a decision about estrogen replacement therapy until further studies look at the effects on dopamine cells of much longer periods of estrogen deprivation. He said the researchers also want to see if much larger doses of estrogen or other hormones administered at 30 days and beyond of estrogen deprivation would resuscitate the cells. All of this must be in the context of possible side effects of hormone replacement that women should take into account in consultation with their doctors.

Other investigators were Robert Roth, professor of psychiatry and pharmacology; John Elsworth, senior research scientist, psychiatry; Frederick Naftolin, M.D., professor of obstetrics and gynecology and of molecular, cellular and developmental biology, and Tamas Horvath, associate professor of obstetrics and gynecology and neurobiology.

The study was carried out at the St. Kitts Biomedical Research Foundation in the West Indies.


Story Source:

The above story is based on materials provided by Yale University. Note: Materials may be edited for content and length.


Cite This Page:

Yale University. "Estrogen Deprivation Leads To Death Of Dopamine Cells In The Brain." ScienceDaily. ScienceDaily, 5 December 2000. <www.sciencedaily.com/releases/2000/12/001204072446.htm>.
Yale University. (2000, December 5). Estrogen Deprivation Leads To Death Of Dopamine Cells In The Brain. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2000/12/001204072446.htm
Yale University. "Estrogen Deprivation Leads To Death Of Dopamine Cells In The Brain." ScienceDaily. www.sciencedaily.com/releases/2000/12/001204072446.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
Ebola Worries End for Dozens on U.S. Watch Lists

Ebola Worries End for Dozens on U.S. Watch Lists

Reuters - US Online Video (Oct. 20, 2014) Forty-three people who had contact with Thomas Eric Duncan, the first person diagnosed with Ebola in the U.S., were cleared overnight of twice-daily monitoring after 21 days of showing no symptoms. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Fauci: Ebola Protocols to Focus on Training

Fauci: Ebola Protocols to Focus on Training

AP (Oct. 20, 2014) Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, says he expects revised CDC protocols on Ebola to focus on training, observation and ensuring health care workers are more protected. (Oct. 20) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins