Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Singing' rats show hope for older humans with age-related voice problems

25.06.2013
A new study shows that the vocal training of older rats reduces some of the voice problems related to their aging, such as the loss of vocal intensity that accompanies changes in the muscles of the larynx. This is an animal model of a vocal pathology that many humans face as they age. The researchers hope that in the future, voice therapy in aging humans will help improve their quality of life.

AUDIO Rats like those used in University of Illinois speech and hearing sciences professor Aaron Johnson’s study make ultrasonic vocalizations (USVs) that are above the range of human hearing, but special recording equipment and a computer that lowers the frequency of the rat calls allows humans to perceive them. As the recording shows, the USVs sound a bit like bird calls.

The research appears in The Journals of Gerontology.

University of Illinois speech and hearing science professor Aaron Johnson, who led the new study along with his colleagues at the University of Wisconsin, said that aging can cause the muscles of the larynx, the organ that contains the vocal folds, to atrophy. This condition, called presbyphonia, may be treatable with vocal training, he said.

Johnson said in a healthy, young larynx the vocal folds completely close and open during vibration. This creates little puffs of air we hear as sound. In people with presbyphonia, however, the atrophied vocal folds do not close properly, resulting in a gap during vocal fold vibration.

Degradation of the neuromuscular junction, or the interface between the nerve that signals the vocal muscle to work and the muscle itself, also contributes to the symptoms of presbyphonia, Johnson said. In a healthy human, when the signal reaches the neuromuscular junction, it triggers a release of chemicals that signal the muscle to contract. But an age-related decline in the neuromuscular junction can cause weakness and fatigue in the muscle, and may result in a person having a breathy or weak voice and to become fatigued as a result of the extra effort needed to communicate.

Surgery and injections may help correct the gap between the vocal folds seen in presbyphonia, but these invasive procedures are often not viable in the elderly population, Johnson said.

His previous experience working with the elderly as a former classical singer and voice teacher propelled Johnson to “become interested in what we can do as we get older to keep our voices healthy and strong.”

“We know exercise strengthens the limb musculature, but we wanted to know if vocal exercise can strengthen the muscles of the voice,” Johnson said.

To find out if vocal training could have an effect on the strength and physiology of the vocal muscles in humans, Johnson turned to a rat model. Rats make ultrasonic vocalizations that are above the range of human hearing, but special recording equipment and a computer that lowers the frequency of the rat calls allows humans to perceive them. (They sound a bit like bird calls).

Because rats and humans utilize similar neuromuscular mechanisms to vocalize, the rats make ideal subjects for the study of human vocal characteristics, Johnson said.

Both the treatment and control groups contained old and young male rats. In the treatment group, a female rat was placed into a cage with a male rat. When the male expressed interest in her, the female was removed from the cage, causing the male rat to vocalize. The male was rewarded with food for these vocalizations, and after eight weeks of this operant conditioning in which rewards were only given for certain responses, all of the rats in the treatment group had been trained to increase their number of vocalizations during a training session.

At the end of the eight-week period, the researchers measured the intensity of the rats’ vocalizations and analyzed the animals’ larynges to see whether the training had any effect on the condition of their neuromuscular junctions.

The researchers found the trained old and young rats had similar average vocal intensities, but the untrained older rats had lower average intensities than both the trained rats and the young rats that had not been trained. They also found several age-related differences within the groups’ neuromuscular mechanisms.

“Other research has found that in the elderly, there is a dispersion, or breaking apart, of the neuromuscular junction at the side that is on the muscle itself,” Johnson said. “We found that in the older rats that received training, it wasn’t as dispersed.”

These “singing rats” are the “first evidence that vocal use and vocal training can change the neuromuscular system of the larynx,” Johnson said.

“While this isn’t a human study, I think this tells us that we can train ourselves to use our voices and not only reduce the effects of age on the muscles of our voices, but actually improve voices that have degraded,” Johnson said.

Johnson is also affiliated with the Beckman Institute for Advanced Science and Technology at Illinois.

Chelsey B. Coombs | EurekAlert!
Further information:
http://www.illinois.edu

More articles from Health and Medicine:

nachricht Plasmonic biosensors enable development of new easy-to-use health tests
14.12.2017 | Aalto University

nachricht ASU scientists develop new, rapid pipeline for antimicrobials
14.12.2017 | Arizona State University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>