Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


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


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:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>