Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers identify key player in respiratory memory


By studying the "memory" of the respiratory system, a group of researchers from the University of Wisconsin-Madison have identified a key player - a protein called BDNF that’s involved in learning - responsible for the body’s ability to keep breathing properly, despite the challenges it may face.

The findings, published Dec. 14 in the online edition of Nature Neuroscience, could provide ideas of new drug targets, which could lead to new treatments for or ways to prevent a number of potentially fatal breathing disorders, including sleep apnea, sudden infant death syndrome and some related to spinal cord injuries, according to the researchers.

Every few seconds, we draw a breath and then release it. If for some reason this routine is interrupted - oxygen levels are low or airways are blocked, for example - our bodies respond accordingly. In the case of oxygen deprivation, the nerve cells in the brain send messages to motor neurons along the spine, which then tell certain muscles involved in breathing to work harder. As a result, a person may take deeper breaths.

If the breathing disruption is experienced regularly, the respiratory system remembers the disruption and most likely will respond more vigorously in the future. Researchers call this change in neural behavior "neuro-plasticity."

In some cases, however, the respiratory system may not remember, says Gordon Mitchell, chair of the comparative biosciences department at UW-Madison’s School of Veterinary Medicine and senior author of the recent paper. He notes that some people who have sleep apnea - a disorder where breathing stops repeatedly during sleep - may have inadequate respiratory memories. He adds that individuals with spinal cord injuries in the neck often must rely on ventilators to help them breathe.

"For them, breathing is a bigger problem than never walking again," says Mitchell. "To breathe is to live."

To allow such patients to breathe more easily, Mitchell and others are exploring the mechanisms underlying respiratory memory so as to find ways to enhance it, such as through drugs.

"If we can understand how breathing changes as a result of experience, we can develop techniques to intervene when breathing is compromised," says Tracy Baker-Herman, a postdoctoral fellow at UW-Madison and first author of the paper.

To begin to uncover these mechanisms, the researchers exposed rats to three five-minute intervals of hypoxia, or decreased oxygen. Sixty minutes after exposure, they recorded the respiratory-related activity levels in the phrenic nerve, which controls the diaphragm muscle. If the activity levels increased after exposure, the researchers would know that the respiratory system, specifically this nerve, had developed a memory of low oxygen.

The Wisconsin scientists did, in fact, record this memory: Activity levels after exposure were 80 percent higher than before the intervals started, suggesting that this nerve remembered experiencing periods of low oxygen levels, says Mitchell.

Making this connection, however, was not enough, says Baker-Herman.

The researchers wanted to know what caused this memory. So, they analyzed segments of spinal cord taken from rats after they had been exposed for 60 minutes to either normal or decreased amounts of oxygen.

The researchers looked specifically for changes in the BDNF protein, or brain derived neurotrophic factor, which is known to sustain and even stimulate neuronal function in the brain. The findings show that intermittent periods of decreased oxygen increased concentrations of the BDNF protein in the phrenic nerve by 56 percent.

Through further testing, the researchers learned that BDNF is, in fact, responsible for increasing activity in this nerve, thereby stimulating a respiratory memory. For example, when the researchers blocked BDNF production in rats with a new technique known as RNA interference and then exposed the rats to intervals of decreased oxygen, they observed no increase in nerve activity. But, when they injected the protein directly into the phrenic nerve of rats they found that neuronal activity increased by 125 percent.

Both findings, says Mitchell, point to the integral role BDNF plays in enhancing the respiratory system’s response to disruptions in breathing. "They show causality between BDNF and phrenic long-term facilitation (or memory)," he says, adding, "the role of BDNF in respiratory plasticity was not known at all before now."

With this new information, Mitchell, Baker-Herman and others in their group continue to search for additional players in respiratory memory. "The closer we get to the ultimate cause," says Mitchell, "the better the chance of developing new pharmaceutical therapies."

These therapies would have the potential not only to restore breathing ability to individuals struck with devastating spinal cord injuries, but also to alleviate the effects of sleep apnea - tiredness, learning impairments, high blood pressure, even death - among the 5 percent of the population with this breathing disorder. Mitchell adds, "The promise for treating other disorders where breathing is disrupted, including sudden infant death syndrome and ALS (Amyotrophic Lateral Sclerosis or Lou Gehrig’s disease) is not trivial."

But he cautions that the basic science behind these disorders is still being learned and that pharmacological treatments will follow only after that knowledge has been gained.

Additional Contacts: Gordon Mitchell, (608) 263-9826,; Tracy Baker-Herman, (608) 263-5013,

Emily Carlson | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

nachricht Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>