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 acetate (MPA), the active in Depo Provera and many widely used menopausal hormone therapies, to impaired 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 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 . 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. 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 , 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 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 search and more info website

not rated yet  

Rank not rated yet
Relevant PhysicsForums posts
  • Potential Breakthrough in Seizure Control
    created9 hours ago
  • Popping/Cracked sternum.
    created14 hours ago
  • Which Mental Illness Encompasses This Problem?
    created14 hours ago
  • A question about drug tolerance
    createdMay 23, 2012
  • Poor nutrition leading to overeating?
    createdMay 23, 2012
  • Math and dyslexia?
    createdMay 21, 2012
  • More from Physics Forums - Medical Sciences

More news stories

Implantable pain disk may help those with cancer

An estimated 3.5 million cancer patients around the globe are in severe pain from their disease, but many get no relief.

Medical research created May 25, 2012 | popularity not rated yet | comments 0 | with audio podcast

Energy levels link sleep control mechanisms

Sleep, or lack of it, can determine level of cognitive performance which is linked with accidents as well as increased risk of serious health problems. Links between cell energy levels, gene transcription ...

Medical research created May 25, 2012 | popularity not rated yet | comments 0

Researchers identify key brain cell in antidepressant action

(Medical Xpress) -- Antidepressant medications such as Prozac have helped improve mood and lessen anxiety in millions of people with major depression. But scientists know surprisingly little about how these drugs work.

Medical research created May 25, 2012 | popularity 4.7 / 5 (3) | comments 0 | with audio podcast

Rockefeller scientists pioneer new method to determine mechanisms of drug action

(Medical Xpress) -- Knowing that a drug works is great. Knowing how it works is a luxury. And until now, determining a drug’s mechanism of action has been a tedious and difficult process for scientists.

Medical research created May 25, 2012 | popularity not rated yet | comments 0 | with audio podcast

Like curry? New biological role identified for compound used in ancient medicine

Scientists have just identified a new reason why some curry dishes, made with spices humans have used for thousands of years, might be good for you.

Medical research created May 25, 2012 | popularity 4.5 / 5 (12) | comments 2 | with audio podcast


Travel to high altitudes tied to Crohn's, colitis flare-ups

(HealthDay) -- People with inflammatory bowel disease, which includes Crohn's disease and colitis, may be at increased risk for flare-ups when they fly or travel to high altitudes for skiing or mountain climbing, ...

Family history of Alzheimer's affects functional connectivity

(HealthDay) -- Cognitively normal individuals with a family history of late-onset Alzheimer's disease (AD) may display lower resting state functional connectivity in the default mode network (DMN) of the brain, ...

Transvaginal mesh op restores pelvic organ prolapse at price

(HealthDay) -- Transvaginal mesh (TVM) procedures are effective for anatomical restoration of pelvic organ prolapse (POP), but patients report a worsening of sexual function following surgery, according to ...

Tongue analysis software uses ancient Chinese medicine to warn of disease

For 5,000 years, the Chinese have used a system of medicine based on the flow and balance of positive and negative energies in the body. In this system, the appearance of the tongue is one of the measures used to classify ...

Skp2 activates cancer-promoting, glucose-processing Akt

HER2 and its epidermal growth factor receptor cousins mobilize a specialized protein to activate a major player in cancer development and sugar metabolism, scientists report in the May 25 issue of Cell.

Early physical therapist treatment associated with reduced risk of healthcare utilization and reduced overall healthcare

A new study published in Spine shows that early treatment by a physical therapist for low back pain (LBP), as compared to delayed treatment, was associated with reduced risk of subsequent healthcare utilization and lower ...