Hormone in birth control shot linked to memory loss
November 1, 2011 in Medical research
The birth control shot Depo Provera offers a convenient alternative for women who don't want to remember to take a daily pill. Ironically, research from Arizona State University has shown the shot actually may impair a person's memory.
The ASU study connects medroxyprogesterone acetate (MPA), the hormone active in Depo Provera and many widely used menopausal hormone therapies, to impaired memory in rodents. The study is currently in press in the journal Psychopharmacology.
The study was led by Blair Braden, an ASU psychology doctoral student, and Heather Bimonte-Nelson, an ASU associate professor of psychology and director of the Bimonte-Nelson Memory and Aging Lab. The work was done in collaboration with Laszlo Prokai from the University of North Texas Health Sciences Center, Fort Worth, Tex., and Alain Simard from Barrow Neurological Institute, Phoenix.
The Bimonte-Nelson lab first linked MPA to memory loss in rats while studying it as a component of hormone therapy for menopause. This earlier study showed that MPA impaired memory in menopausal-aged rats, and results were published in the November 2010 issue of Neurobiology of Learning and Memory. The current study specifically looks at the drug in relation to the birth control shot.
Bimonte-Nelson said she and Braden began asking questions about the effects of the drug because Braden was concerned about friends taking MPA as a contraceptive.
"This is an important question, because what we are going to have in our future are women who are menopausal that also have a history of taking MPA as birth control when they were younger," said Bimonte-Nelson.
The U.S. Food and Drug Administration originally approved Depo Provera for use in October 1992. It requires an injection every 12 weeks. Its 99 percent effectiveness and the infrequency of doses make the shot an attractive alternative for women seeking to avoid pregnancy.
While other studies have examined Depo Provera's effects on bone density, Bimonte-Nelson's lab is the first to explore its effects on cognition. The researchers note that other forms of hormonal contraception, such as the pill, do not use MPA.
The study lasted approximately one year, using three groups of rats (which received doses at varying ages), plus a control group that did not receive the hormone. To test their memory, rats were placed in water-based mazes to swim and seek out hidden platforms in the water.
"What we found was pretty shocking animals that had been given the drug at any point in their life were memory impaired at middle age compared to animals that never had the drug," said Braden. "We also confirmed that in the subjects that only received the drug when young, the hormone was no longer circulating during memory testing when older, showing it had cleared from the system yet still had effects on brain function."
The researchers also measured a marker of the gamma-aminobutyric acid (GABA) neurotransmitter system in the hippocampus of the rats' brains to determine MPA's physiological effects.
"What GABA does is slow the brain down," Braden said. "So if there is too much of it, it can make it more difficult to produce memories. But then if there's too little of it and there's too much excitation, same thing it makes you not able to produce memories correctly."
The group plans to follow the animal studies with human trials, and the work is leading to results that could have profound implications for women of all ages.
"This research shows that even after this hormone is no longer on board, months and months later, resulting effects are impacting the brain and its function," Bimonte-Nelson said. "This work is an important step forward in our understanding of the potentially long-lasting effects of clinically used hormones on brain function. However, more research is needed to determine whether these effects also occur in women that take this hormone as birth control or part of hormone therapy."
More information: An early online version of the article is available at http://www.springerlink.com/content/53357212117581w6/.
Provided by
Arizona State University
-
Oregon study raises questions on synthetic progestins
Mar 10, 2008 |
not rated yet |
0
-
Hormone therapy linked to brain shrinkage, but not lesions
Jan 12, 2009 |
not rated yet |
0
-
Vascular drug found to improve learning and memory in middle-aged rats
Feb 02, 2009 |
not rated yet |
0
-
Breast cancer risk varies among different progestins used in hormone replacement therapy
Aug 10, 2010 |
not rated yet |
0
-
Older age memory loss tied to stress hormone receptor in brain
Apr 06, 2011 |
not rated yet |
0
-
Motion perception revisited: High Phi effect challenges established motion perception assumptions
Apr 23, 2013 |
3 / 5 (2) |
2
-
Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update)
Apr 02, 2013 |
4.5 / 5 (11) |
5
-
The visual system as economist: Neural resource allocation in visual adaptation
Mar 30, 2013 |
5 / 5 (2) |
9
-
Separate lives: Neuronal and organismal lifespans decoupled
Mar 27, 2013 |
4.9 / 5 (8) |
0
-
Sizing things up: The evolutionary neurobiology of scale invariance
Feb 28, 2013 |
4.8 / 5 (10) |
14
-
Why is zone 1 in liver more prone to ischemic injury?
May 23, 2013
-
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013
-
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013
-
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013
-
If you became brain-dead, would you want them to pull the plug?
May 17, 2013
-
MRI bill question
May 15, 2013
- More from Physics Forums - Medical Sciences
More news stories
Study reveals new mechanism for estrogen suppression of liver lipid synthesis
By discovering the new mechanism by which estrogen suppresses lipid synthesis in the liver, UC Irvine endocrinologists have revealed a potential new approach toward treating certain liver diseases.
Medical research
May 23, 2013 |
5 / 5 (1) |
0
|
MRI-based measurement helps predict vascular disease in the brain
Aortic arch pulse wave velocity, a measure of arterial stiffness, is a strong independent predictor of disease of the vessels that supply blood to the brain, according to a new study published in the June issue the journal ...
Medical research
May 23, 2013 |
not rated yet |
0
Antibiotics: A new understanding of sulfonamide nervous system side effects
Since the discovery of Prontosil in 1932, sulfonamide antibiotics have been used to combat a wide spectrum of bacterial infections, from acne to chlamydia and pneumonia. However, their side effects can include serious neurological ...
Medical research
May 23, 2013 |
3 / 5 (1) |
0
|
Scientists discover molecule triggers sensation of itch
Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as ...
Medical research
May 23, 2013 |
5 / 5 (3) |
0
|
Discarded immune cells induce the relocation of stem cells
Spanish researchers have discovered that the daily clearance of neutrophils from the body stimulates the release of hematopoietic stem cells from the bone marrow into the bloodstream, according to a report published today ...
Medical research
May 23, 2013 |
5 / 5 (2) |
0
Heart failure accelerates male 'menopause'
Heart failure accelerates the aging process and brings on early andropausal syndrome (AS), according to research presented today at the Heart Failure Congress 2013. AS, also referred to as male 'menopause', was four times ...
First drug to improve heart failure mortality in over a decade
Coenzyme Q10 decreases all cause mortality by half, according to the results of a multicentre randomised double blind trial presented today at Heart Failure 2013 congress. It is the first drug to improve heart failure mortality ...
Feds fight morning-after pill age ruling in NY
(AP)—Department of Justice lawyers have again asked a federal appeals court in New York to delay lifting age restrictions and prescription requirements on an emergency contraceptive popularly known as the morning-after ...
Death highest in heart failure patients admitted in January, on Friday, and overnight
Mortality and length of stay are highest in heart failure patients admitted in January, on Friday, and overnight, according to research presented today at the Heart Failure Congress 2013. The analysis of nearly 1 million ...
Engineered cytomegalovirus protects monkeys from HIV equivalent
(Medical Xpress)—A new study by researchers in the US has shown that an ancient virus can be modified to help in the fight against the simian immunodeficiency virus SIV, which is the equivalent in monkeys ...
Researchers identify first drug targets in childhood genetic tumor disorder
Two mutations central to the development of infantile myofibromatosis (IM)—a disorder characterized by multiple tumors involving the skin, bone, and soft tissue—may provide new therapeutic targets, according to researchers ...