Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

‘Good’ chemical, neurons in brain elevated among exercise addicts

29.09.2003


Exercise enthusiasts have more reasons to put on their running shoes in the morning, but an Oregon Health & Science University scientist says they shouldn’t step up their work-outs just yet.



A study published today in the journal Neuroscience, journal of the International Brain Research Organization, confirmed that exercise increases the chemical BDNF – brain-derived neurotrophic factor – in the hippocampus, a curved, elongated ridge in the brain that controls learning and memory. BDNF is involved in protecting and producing neurons in the hippocampus.

"When you exercise, it’s been shown you release BDNF," said study co-author Justin Rhodes, Ph.D., a postdoctoral fellow in the Department of Behavioral Neuroscience at OHSU’s School of Medicine and at the Veterans Administration Medical Center in Portland. "BDNF helps support and strengthen synapses in the brain. We find that exercise increases these good things."


Mice bred for 30 generations to display increased voluntary wheel running behavior – an "exercise addiction" – showed higher amounts of BDNF than normal, sedentary mice. In fact, the BDNF concentration in the active mice increased by as much as 171 percent after seven nights of wheel running.

"These mice are more active than wild mice," Rhodes said, referring to the mice as small and lean, and seemingly "addicted" to exercise. "Wheel running causes a huge amount of activity in the hippocampus. The more running, the more BDNF."

In a study Rhodes also co-authored that extends these findings, to be published in the October edition of the American Psychological Association journal Behavioral Neuroscience, scientists demonstrated that not only do the mice display more of this "good" BDNF chemical in the hippocampus, they grow more neurons there as well.

But those high levels of BDNF and neurogenesis don’t necessarily mean an exercise addict learns at a faster rate, Rhodes said. According to the Behavioral Neuroscience study, the running addict, compared with the normal-running, control mice, perform "terribly" when attempting to navigate around a maze.

"These studies are focusing on the effects of exercise itself on chemicals known to protect and strengthen synapses," Rhodes explained. "But too much of it is not necessarily a good thing."

High runners tend to "max out" in the production of the BDNF and neurogenesis, Rhodes said. And that topping-out effect may be what prevents learning.

A high-running mouse’s inability to learn as well as a normal mouse could be due to less biological reasons, Rhodes points out. "It is possible that they’re so focused on running, they can’t think of anything else," he said.

Rhodes and colleagues at the University of Wisconsin at Madison, the University of California at Riverside and The Salk Institute also emphasize that the functional significance of the exercise-induced increases in BDNF and neurogenesis is not known.

Rhodes suggests that when a high-running mouse exercises, stress is placed on its hippocampus and the development of new neurons becomes a protective response. No one has yet tested whether hyperactive wheel running exercise actually kills or damages neurons in the hippocampus, he said.

"The reason why these good things are happening is they may clean up some of the mess," he said. "Knowing that, you wouldn’t expect high runners to get any benefit from it."

One thing is clear: Exercise greatly activates the hippocampus. Rhodes and his colleagues have conducted research that also shows the intensity of exercise is linearly related to the number of neurons that are activated in a subregion of the hippocampus called the dentate gyrus.

In addition, they have demonstrated that when mice are kept from their normal running routine, brain regions involved in craving for natural rewards such as food, sex and drugs of abuse become activated. It is allowing Rhodes to study the relationship between natural craving, like hunger, and drug craving due to a pathological addiction.

"The point is to characterize what makes drug craving different from natural craving at the level of the genes and neuronal substrates involved so that, eventually, a pharmaceutical therapy can be designed to target the pathology," Rhodes said.

Jonathan Modie | EurekAlert!
Further information:
http://www.ohsu.edu/

More articles from Studies and Analyses:

nachricht Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>