Cough is a vital protective reflex that clears the respiratory tract of threats from mechanical stimuli like food and chemical stimuli such as airborne toxins and pollutants. As such, cough is necessary to protect the lungs, keep airways clear, and preserve life.
"Individuals with a weak cough reflex are at increased risk of pneumonia and of choking. Conversely, many acute and chronic conditions involve frequent coughing, leading to 30 million health care visits annually, with billions spent on over-the-counter medications and billions more lost due to reduced productivity," said lead author, Paul M. Wise, Ph.D., a sensory psychologist at Monell.
However, many aspects of coughing remain poorly understood, including how chemicals act to trigger and modulate cough.
In the current study, which appears in the June 2012 issue of Pulmonary Pharmacology and Therapeutics, 12 healthy young adults inhaled from a nebulizer containing capsaicin, the burning ingredient in chili peppers and a potent chemical stimulus for cough.
After each inhalation, the amount of capsaicin was doubled. This procedure continued until the subject coughed three times within 10 seconds. The capsaicin concentration that induced the three coughs was labeled as the individual's cough threshold.
In some sessions, the subjects held either a very sweet sucrose or plain water in their mouths for three seconds, spat the liquid into a sink, and then inhaled from the nebulizer.
In other sessions, subjects inhaled three breaths of either menthol-saturated air or clean air before each capsaicin inhalation. The menthol concentration was selected to approximate the cooling intensity of a menthol cigarette.
Both sucrose and menthol increased the amount of capsaicin needed to elicit a cough relative to plain water or clean air, respectively. Sucrose increased cough threshold by about 45 percent, while menthol increased it by approximately 25 percent.
"This is the first study to empirically show that sweet taste reduces cough. This also is the first study to show that menthol alone can reduce coughing in response to a cough-eliciting agent," said Monell sensory scientist Paul Breslin, Ph.D., an author on the study.
The findings support the hypothesis that adding menthol to cigarettes, popularly known as "menthols," may make it easier to begin smoking by suppressing the cough reflex, thus making the first cigarettes less distressing.
"Menthol may dull the sensitivity of sensory nerves in the airways and thereby actually disable an important reflex mechanism that would otherwise protect smokers from the chemical and particulate irritants present in cigarette smoke," said Wise.
Studies at Monell will continue to explore the chemical elicitation of cough, along with the receptors and genes involved in this system.
Also contributing to the research was Pamela Dalton, Ph.D., of Monell. Breslin also holds a position as professor in the Department of Nutritional Sciences at Rutgers University. Funding was provided by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health.
The Monell Chemical Senses Center is an independent nonprofit basic research institute based in Philadelphia, Pennsylvania. Monell advances scientific understanding of the mechanisms and functions of taste and smell to benefit human health and well-being. Using an interdisciplinary approach, scientists collaborate in program areas of sensation and perception; neuroscience and molecular biology; environmental and occupational health; nutrition and appetite; health and well-being; development, aging and regeneration; and chemical ecology and communication. For more information about Monell, visit www.monell.org.
Leslie Stein | EurekAlert!
Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications
Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State
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...
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:...
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...
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...
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...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine