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 July 29, 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 July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) 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:
from the past week

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