- Introduction to Clinical Research Training
- Medical Education
- United Kingdom Clinical Scholars Research Training
- Vanderbilt Hall
- What it Means to Be a Harvard Doctor
- Diversity Commitment
- Tuition, Fees, & Expenses
- Interview Day
- The Neighborhood
- Admissions FAQs
- Admissions Publications
- Contact Admissions
- Financial Aid
- Office of the Registrar
- Campus Planning and Facilities
- Ombuds Office
- Committee on Microbiological Safety
- Human Resources
- HMS Foundation Funds
- Office for Academic and Clinical Affairs
- Joint Committee on the Status of Women
- The Academy
- Global Health Research Core
- Global Clinical Scholars Research Training Program
- HMA Standing Committee on Animals
- Office of Research Compliance
- Global & Community Health
- Harvard Medical School Event Calendar
- Contact @HMS
- Office of Diversity RIA Program
- The Dean's Perspective
- Department of Pathology
- Harvard Mahoney Neuroscience Institute
- OHRA Home
- Office of Research Subject Protection
- Tools and Technology
- Alumni Association
- Cancer Biology & Therapeutics Program
- HMS Community Values Initiative
- HMS Information Technology
- HMS TransMed Program
- Introduction to the Practice of American Medicine
- Office of Communications & External Relations
- Office of Global Education
- Shenzhen-HMS Initiative in International Education
- South American Clinical Research Training
- test page
- Safety Quality and Informatics Leadership
- Human Resources
- Jobs @ HMS
- Contact us
- Dental Medicine
- Harvard University
Environment Counts, Alzheimer’s Research Suggests
March 13, 2013
Previous studies have shown that exercise, an active mind and social interaction may help delay the onset of dementia in Alzheimer’s patients, but now a new study indicates environment also plays a key role.
The study, led by Dennis Selkoe, Vincent and Stella Coates Professor of Neurologic Diseases in the HMS Department of Neurology and Brigham and Women’s Hospital, provides specific, preclinical evidence supporting the concept that prolonged and intensive stimulation by an enriched environment—especially regular exposure to new activities—may have beneficial effects in delaying one of the key negative factors in Alzheimer’s disease.
“This part of our work suggests that prolonged exposure to a richer, more novel environment beginning even in middle age might help protect the hippocampus from the bad effects of amyloid beta, which builds up to toxic levels in 100 percent of Alzheimer’s patients,” said Selkoe
Researchers used a wild-type mouse model to evaluate how the environment might affect the progression of Alzheimer’s. Unlike other preclinical models used in Alzheimer’s research, wild-type mice tend to more closely mimic the scenario of disease development in humans under normal environmental conditions, rather than in individuals with a strong genetic predisposition to the disease.
Alzheimer’s disease occurs when amyloid beta protein accumulates and forms so-called senile plaques in the brain. This protein accumulation can block nerve cells in the brain from properly communicating with one another. This may lead to a gradual erosion of an individual’s mental processes, such as memory, attention and the ability to learn, understand and process information.
Selkoe and his team found that prolonged exposure to an enriched environment activated certain adrenalin-related brain receptors. The activity triggered a signaling pathway that prevented the amyloid beta protein from weakening the communication between nerve cells in the hippocampus, which plays an important role in both short- and long-term memory.
The ability of an enriched, novel environment to prevent amyloid beta protein from affecting the signaling strength and communication between nerve cells was seen in both young and middle-aged wild-type mice.
Moreover, the scientists found that exposing the brain to novel activities in particular provided greater protection against Alzheimer’s disease than did just aerobic exercise. According to the researchers, this observation may be due to stimulation that occurred not only physically, but also mentally, when the mice moved quickly from one novel object to another.
“This work helps provide a molecular mechanism for why a richer environment can help lessen the memory-eroding effects of the buildup of amyloid beta protein with age,” said Selkoe. “They point to basic scientific reasons for the apparent lessening of [Alzheimer’s disease] risk in people with cognitively richer and more complex experiences during life.”
This work was supported by the National Institutes of Health, the Massachusetts Alzheimer’s Disease Research Center, the Massachusetts General Hospital Neurology Clinical Trials Units, and the Harvard NeuroDiscovery Center.
Adapted from Brigham and Women’s Hospital news release.