Featured Research

from universities, journals, and other organizations

Exercise Improves Learning And Memory

Date:
November 10, 1999
Source:
Howard Hughes Medical Institute
Summary:
Chalk up another benefit for regular exercise. Investigators from the Howard Hughes Medical Institute (HHMI) have found that voluntary running boosts the growth of new nerve cells and improves learning and memory in adult mice.

November 9, 1999 — Chalk up another benefit for regular exercise. Investigators from the Howard Hughes Medical Institute (HHMI) have found that voluntary running boosts the growth of new nerve cells and improves learning and memory in adult mice.

"Until recently it was thought that the growth of new neurons, or neurogenesis, did not occur in the adult mammalian brain," said Terrence Sejnowski, an HHMI investigator at The Salk Institute for Biological Studies. "But we now have evidence for it, and it appears that exercise helps this happen."

Sejnowski, Salk colleague Fred Gage, and postdoctoral fellows Henriette van Praag and Brian Christie, published their findings in the November 9, 1999, issue of Proceedings of the National Academy of Sciences.

The investigators began their study by comparing the memory skills of a group of sedentary mice to those of a group of mice who exercised freely on a running wheel for one month. Mice in the exercise group logged an average daily distance of 4.87 kilometers, or 2.92 miles.

Both groups were trained to locate a submerged camouflaged platform in a maze that was lying just below the surface in cloudy water. Mice dislike swimming and instinctively seek the platform as a refuge from the stressful activity.

"We can't ask a mouse if it remembered where the platform was located, so we measure long-term memory by having them swim to the platform," said Sejnowski.

After six days of training each group of mice for the swimming task, the researchers began the study. The group of mice that had been exercising made a beeline for the platform. In contrast, the sedentary mice took significantly longer paths and times to find the dock. The path chosen and time taken reflect long-term memory, or how well the mice recall the platform's location. Based on the swimming test, mice in the exercise group were better able to remember the platform's location compared to mice in the sedentary group.

Next the researchers looked for changes in the number of nerve cells between the two groups of animals. In comparison to sedentary mice, the brains of mice that exercised had about 2.5 times more new nerve cells.

New nerve cells were not distributed evenly throughout the brain, but were concentrated in the dentate gyrus, a section of a larger area of the brain called the hippocampus. The hippocampus plays a central role in many memory formation processes, including spatial learning—locating objects in the environment—and consciously recalling facts, episodes, and unique events.

The investigators also examined brain slices from the two groups of mice in order to measure a nerve-signaling process known as long-term potentiation, or LTP. A large body of research supports the theory that LTP—essentially a strengthening of the synaptic connections between two neurons—is the primary mechanism involved in the formation and storage of long-term memories by humans and animals.

"Presumably, LTP affects the flow of information through synapses, the connections between two nerve cells," said Sejnowski. Neurons communicate with each other by sending signals through synapses.

Examination of the tissue slices showed that the exercising mice displayed twice as much long-term potentiation compared to their sedentary counterparts. And, as was the case with neurogenesis, increased LTP occurred only in the dentate gyrus.

"These observations support the idea that exercise enhances the formation and survival of new nerve cells as well as the connections between nerve cells, which in turn improves long-term memory," Sejnowski explained. He added that these data also confirm that the structural and physiological changes that occurred in the dentate gyrus correlate with a learning behavior associated with this region of the brain.

Numerous human studies have shown that exercise increases alertness and helps people to think more clearly. Recently, Gage demonstrated that new nerve cells grow in the adult human dentate gyrus. If the same correlation between exercise, nerve cell growth and memory observed in mice plays out in the humans, "exercise could help you remember the name of the person you met yesterday to or where you parked your car," said Sejnowski.

In future experiments, Sejnowski and his colleagues will follow individual mice to see whether longer running times generate more new nerve cells and stronger long-term potentiation. They will also explore if other factors, such as hormones released by exercise, influence memory and nerve cell growth. "We still don't have the causal link between exercise and neurogenesis," said Sejnowski.


Story Source:

The above story is based on materials provided by Howard Hughes Medical Institute. Note: Materials may be edited for content and length.


Cite This Page:

Howard Hughes Medical Institute. "Exercise Improves Learning And Memory." ScienceDaily. ScienceDaily, 10 November 1999. <www.sciencedaily.com/releases/1999/11/991110061936.htm>.
Howard Hughes Medical Institute. (1999, November 10). Exercise Improves Learning And Memory. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/1999/11/991110061936.htm
Howard Hughes Medical Institute. "Exercise Improves Learning And Memory." ScienceDaily. www.sciencedaily.com/releases/1999/11/991110061936.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