Category: Science News

{While the romantic poets’ idea of memories being akin to spirits may have poetic merit, the scientists’ perspective is that memories are concrete, physical entities that can be visualized within various regions of the brain.}

Scientists from the Florida campus of The Scripps Research Institute (TSRI) have now for the first time identified a sub-region in the brain that works to form a particular kind of memory: fear-associated with a specific environmental cue or “contextual fear memory.”

The study, recently published in the journal Biological Psychiatry Cognitive Neuroscience and Neuroimaging, was led by TSRI Associate Professor Sathyanarayanan V. Puthanveettil.

“Much is still unknown about the identities of proteins synthesized to produce long-term memory,” Puthanveettil said. “The most striking observation from the new study is that the medial prefrontal cortex is the site of this early protein synthesis. We have also identified what proteins are newly synthesized in the medial prefrontal cortex.”

In particular, the study showed new protein synthesis in a specific sub-region of the prefrontal cortex known in rodents as the prelimbic. In humans, this area corresponds to the anterior cortex, which has been linked to processing emotional responses. Initially, Puthanveettil and his colleagues ignored the medial prefrontal cortex because no one believed that it had anything to do with early encoding of long term memories.

However, when they closely examined the effects on the brain of conditioning rodents with a mild foot shock, the scientists found several messenger RNAs recruited to polyribosomes in the medial prefrontal cortex — a clear indication of new protein synthesis there.

Puthanveettil and his colleagues also discovered that if they inhibited new protein synthesis in the prelimbic region right after fear conditioning took place, those memories did not form. But if the researchers waited just a few hours, inhibiting protein synthesis in prelimbic cortex had no impact and the memories took hold. There is temporal and spatial regulation of new protein synthesis in the medial prefrontal cortex.

“It may be that the first wave of protein synthesis is critical for encoding contextual fear memory, while second wave in other sub-regions is important for memory storage,” he said. It remains to be determined if other sub-regions of the cortex are also be involved in the synthesis of memory proteins.

“The medial prefrontal cortex has many sub-regions,” said TSRI Senior Research Associate Bindu L. Raveendra, co-first author of the study with Valerio Rizzo, Khalid Touzani and Supriya Swarnkar, all of TSRI at the time of the study. “But the specific roles of these sub-regions in encoding, expression and retrieval, as well as their underlying molecular mechanisms, remain to be unraveled.”

{Birds’ beaks come in an incredible range of shapes and sizes, adapted for survival in environments around the world. But as a new study from The Auk: Ornithological Advances reveals, there’s even more to bird beaks than meets the eye — the insides of birds’ bills are filled with complex structures that help them meet the demands of hot climates.}

Nasal conchae are complex structures inside bird bills that moderate the temperature of air being inhaled and reclaim water from air being exhaled. Raymond Danner of the University of North Carolina Wilmington and his colleagues from Cornell University and the National Museum of Natural History used CT scans to examine the conchae of two Song Sparrow subspecies, one that lives in warm, dry sand dunes and one that lives in moister habitats farther inland. In this first comparison of conchae structure from birds living along a moisture gradient, the conchae of the dune-dwelling sparrows had a larger surface area and were situated farther out in the bill than those of their inland relatives, hypothetically increasing their beaks’ ability to cool air and recapture water.

Danner and his colleagues used Song Sparrow specimens that were collected in Delaware and the District of Columbia and preserved in ethanol and iodine to help soft tissues show up in scans. The contrast-enhanced CT scans they used to visualize the insides of the sparrows’ bills is a relatively new technique that is letting researchers see the details of these soft, cartilaginous structures for the first time.

“We had been studying the function of the bird bill as a heat radiator, with a focus on heat loss from the external surface and adaptation to local climates, when we began to wonder about the thermoregulatory processes that occur within the bill,” says Danner. “I remember the entire team assembled for the first time, huddled around a computer and looking in amazement at the first scans. The high resolution scans revealed many structures that we as experienced ornithologists had never seen or even imagined, and we were immediately struck by the beauty of the ornately structured anterior conchae and the neatly scrolled middle conchae.”

“This study highlights the remarkable complexity of the rostral conchae in songbirds. This complexity has gone largely unnoticed due to the ways in which most birds are collected and preserved,” according to Jason Bourke, a researcher from the North Carolina Museum of Natural Sciences who was not involved in the research. “Thanks to the use of innovative techniques like diceCT, we are now able to really appreciate just how complicated bird noses can be.”

{Chicks that are competing with siblings or whose parents are likely to die or switch partners tend to be less honest when begging for food, research into sibling rivalry in birds by Oxford University scientists has found.}

That’s because these events introduce conflict into the family group.

Analysis of more than 100 studies across 60 species of bird also found that chicks are more likely to exaggerate their need for food if their parents are likely to breed again in the future — backing up existing evolutionary theory about natural selection.

The results are published in the journal PNAS.

Co-author Shana Caro, a doctoral candidate in Oxford’s Department of Zoology, said: ‘We hypothesised that you could explain the relative levels of honesty among chicks across species based on how much conflict exists. A chick that has the nest to itself is always going to get the worm, but if you add other chicks then there is going to be conflict over food resources.

‘We wanted to see whether dishonesty increases as the number of siblings sharing a nest increases.’

The researchers mathematically analysed 108 scientific studies featuring information relating to the begging behaviour of chicks across 60 species. They took into account factors such as birds’ condition, number of siblings, and relatedness to siblings.

Shana Caro said: ‘We found that offspring are less honest about their need for food when they face competition from current siblings, when their parents are likely to breed again, and when parental divorce or death means any future siblings can only be half, not full, siblings. In short, anything that brings in conflict is detrimental to honesty. Over millions of years, natural selection has caused species with higher levels of conflict to evolve chicks that beg for food even when they don’t need it.’

She added: ‘If parents die or switch partners, all future siblings can only be half siblings. Chicks do not “benefit” from an evolutionary point of view when their parents feed unrelated chicks, and they only benefit half as much if their parents feed half siblings. However, they could benefit a lot if their parents feed their full siblings, because those siblings could give them nieces and nephews, helping to continue the bloodline.

‘While dishonesty when competing against existing siblings for food might be expected, what’s interesting is that these results show that unborn birds — which may or may not ever exist — have an effect on the behaviour of chicks. This may be because if parents are saving resources for future breeding attempts, they could be less responsive to their current brood’s begging. It’s therefore in chicks’ interests to exaggerate their begging to make sure they get enough food and aren’t disadvantaged by their parents’ attempts to save energy.’

Begging for food can take the form of chicks calling out, flapping their wings, or opening their mouths as wide as possible. The most honest species, according to the meta-analysis, tend to be long-lived, single-mate seabirds such as the shearwater or albatross, while dishonesty is most prevalent among species such as blackbirds or great tits, which produce larger broods and tend to breed with different mates.

{Scientists from the University of Bristol and partner universities in Germany, France, Canada and Wales, have discovered a huge magmatic lake, 15 kilometres below a dormant volcano in Bolivia, South America.
}

The body of water — which is dissolved into partially molten rock at a temperature of almost 1,000 degrees Celsius — is the equivalent to what is found in some of the world’s giant freshwater lakes, such as Lake Superior.

The find has now led scientists to consider if similar bodies of water may be ‘hiding’ under other volcanoes and could help explain why and how volcanoes erupt.

Professor Jon Blundy, from the School of Earth Sciences, took part in an international multidisciplinary research project at Cerro Uturuncu volcano in the Bolivian Altiplano.

He said: “The Bolivian Altiplano has been the site of extensive volcanism over past 10 million years, although there are no currently active volcanoes there.

“The Altiplano is underlain by a large geophysical anomaly at depths of 15 km below the surface of Earth.

“This anomaly has a volume of one-and-a-half million cubic kilometres or more and is characterised by reduced seismic wave speeds and increased electrical conductivity. This indicates the presence of molten rock.

“The rock is not fully molten, but partially molten. Only about 10 to 20 percent of the rock is actually liquid; the rest is solid. The rock at these depths is at a temperature of about 970°C.”

In order to characterise the partially molten region the team performed high temperature and pressure experiments at the University of Orléans in France.

This measured the electrical conductivity of the molten rock in the ‘anomalous’ region and concluded that there must be about eight to ten percent of water dissolved in the silicate melt.

Professor Blundy added: “This is a large value. It agrees with estimates made for the volcanic rocks of Uturuncu using high temperature and pressure experiments to match the chemical composition of crystals.

“Silicate melt can only dissolve water at high pressure; at lower pressure this water comes out of the solution and forms bubbles. Crucially — these bubbles can drive volcanic eruptions.

“The eight to ten percent of water dissolved in the massive anomaly region amounts to a total mass of water equivalent to what is found in some of the giant freshwater lakes of North America.”

Professor Fabrice Gaillard at University of Orléans explained: “Ten per cent by weight of dissolved water means that there is one molecule of water for every three molecules of silicate. This is an extraordinarily large fraction of water, helping to explain why these silicate liquids are so electrically conductive.”

The researchers hope that better understanding of how water can trigger volcanic eruptions can improve predictions of when it is going to erupt.

{Study of rare genetic disorder reveals importance of touch and body awareness.}

With the help of two young patients with a unique neurological disorder, an initial study by scientists at the National Institutes of Health suggests that a gene called PIEZO2 controls specific aspects of human touch and proprioception, a “sixth sense” describing awareness of one’s body in space. Mutations in the gene caused the two to have movement and balance problems and the loss of some forms of touch. Despite their difficulties, they both appeared to cope with these challenges by relying heavily on vision and other senses.

“Our study highlights the critical importance of PIEZO2 and the senses it controls in our daily lives,” said Carsten G. Bönnemann, M.D., senior investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and a co-leader of the study published in the New England Journal of Medicine. “The results establish that PIEZO2 is a touch and proprioception gene in humans. Understanding its role in these senses may provide clues to a variety of neurological disorders.”

Dr. Bönnemann’s team uses cutting edge genetic techniques to help diagnose children around the world who have disorders that are difficult to characterize. The two patients in this study are unrelated, one nine and the other 19 years old. They have difficulties walking; hip, finger and foot deformities; and abnormally curved spines diagnosed as progressive scoliosis.

Working with the laboratory of Alexander T. Chesler, Ph.D., investigator at NIH’s National Center for Complementary and Integrative Health (NCCIH), the researchers discovered that the patients have mutations in the PIEZO2 gene that appear to block the normal production or activity of Piezo2 proteins in their cells. Piezo2 is what scientists call a mechanosensitive protein because it generates electrical nerve signals in response to changes in cell shape, such as when skin cells and neurons of the hand are pressed against a table. Studies in mice suggest that Piezo2 is found in the neurons that control touch and proprioception.

“As someone who studies Piezo2 in mice, working with these patients was humbling,” said Dr. Chesler. “Our results suggest they are touch-blind. The patient’s version of Piezo2 may not work, so their neurons cannot detect touch or limb movements.”

Further examinations at the NIH Clinical Center suggested the young patients lack body awareness. Blindfolding them made walking extremely difficult, causing them to stagger and stumble from side to side while assistants prevented them from falling. When the researchers compared the two patients with unaffected volunteers, they found that blindfolding the young patients made it harder for them to reliably reach for an object in front of their faces than it was for the volunteers. Without looking, the patients could not guess the direction their joints were being moved as well as the control subjects could.

The patients were also less sensitive to certain forms of touch. They could not feel vibrations from a buzzing tuning fork as well as the control subjects could. Nor could they tell the difference between one or two small ends of a caliper pressed firmly against their palms. Brain scans of one patient showed no response when the palm of her hand was brushed.

Nevertheless, the patients could feel other forms of touch. Stroking or brushing hairy skin is normally perceived as pleasant. Although they both felt the brushing of hairy skin, one claimed it felt prickly instead of the pleasant sensation reported by unaffected volunteers. Brain scans showed different activity patterns in response to brushing between unaffected volunteers and the patient who felt prickliness.

Despite these differences, the patients’ nervous systems appeared to be developing normally. They were able to feel pain, itch, and temperature normally; the nerves in their limbs conducted electricity rapidly; and their brains and cognitive abilities were similar to the control subjects of their age.

“What’s remarkable about these patients is how much their nervous systems compensate for their lack of touch and body awareness,” said Dr. Bönnemann. “It suggests the nervous system may have several alternate pathways that we can tap into when designing new therapies.”

Previous studies found that mutations in PIEZO2 may have various effects on the Piezo2 protein that may result in genetic musculoskeletal disorders, including distal arthrogryposis type 5, Gordon Syndrome, and Marden-Walker Syndrome. Drs. Bönnemann and Chesler concluded that the scoliosis and joint problems of the patients in this study suggest that Piezo2 is either directly required for the normal growth and alignment of the skeletal system or that touch and proprioception indirectly guide skeletal development.

“Our study demonstrates that bench and bedside research are connected by a two-way street,” said Dr. Chesler. “Results from basic laboratory research guided our examination of the children. Now we can take that knowledge back to the lab and use it to design future experiments investigating the role of PIEZO2 in nervous system and musculoskeletal development.”

This work was supported by the NCCIH and NINDS intramural research programs.

{Psychologists identify key characteristics of earworms.}

If you’ve found yourself singing along to Lady Gaga’s “Bad Romance” hours after you switched the radio off, you are not alone. Certain songs do tend to stick in our heads more than others for some very specific reasons, according to research published by the American Psychological Association.

These songs, often called earworms, are usually faster, with a fairly generic and easy-to-remember melody but with some particular intervals, such as leaps or repetitions that set them apart from the average pop song, according to the first large-scale study of earworms. The article appears online in the APA journal Psychology of Aesthetics, Creativity and the Arts.

In addition to “Bad Romance,” examples of common earworms named in the study include “Don’t Stop Believing” by Journey and, perhaps not surprisingly, “Can’t Get You Out Of My Head” by Kylie Minogue.

“These musically sticky songs seem to have quite a fast tempo along with a common melodic shape and unusual intervals or repetitions like we can hear in the opening riff of ‘Smoke On The Water’ by Deep Purple or in the chorus of ‘Bad Romance,’” said the study’s lead author, Kelly Jakubowski, PhD, of Durham University. She conducted the study while at Goldsmiths, University of London.

Earworms are also more likely to get more radio time and be featured at the top of the charts, which is not surprising. However, there has previously been limited evidence about what makes such songs catchy regardless of popularity or how often people may have heard them.

“Our findings show that you can, to some extent, predict which songs are going to get stuck in people’s heads based on the song’s melodic content. This could help aspiring song-writers or advertisers write a jingle everyone will remember for days or months afterwards,” said Jakubowski.

The study found that the tunes most likely to get stuck in people’s heads were those with more common global melodic contours, meaning they have overall melodic shapes commonly found in Western pop music. For example, one of the most common contour patterns is heard in “Twinkle, Twinkle Little Star,” where the first phrase rises in pitch and the second falls. Numerous other nursery tunes follow the same pattern, making them easy for young children to remember, according to the authors. The opening riff of “Moves Like Jagger” by Maroon 5, one of the top named earworm tunes in the study, also follows this common contour pattern of rising then falling in pitch.

In addition to a common melodic shape, the other crucial ingredient in the earworm formula is an unusual interval structure in the song, such as some unexpected leaps or more repeated notes than you would expect to hear in the average pop song, according to the study. The instrumental interlude of “My Sharona” by the Knack and “In The Mood” by Glen Miller both have this unusual interval structure.

The researchers asked 3,000 people to name their most frequent earworm tunes and compared these to tunes that had never been named as earworms in the database but were a match in terms of popularity and how recently they had been in the United Kingdom music charts. The melodic features of the earworm and non-earworm tunes were then analyzed and compared. Songs were limited to popular genres, such as pop, rock, rap and rhythm and blues. The data for the study were collected from 2010 to 2013.

Studies of earworms can help to understand how brain networks, which are involved in perception, emotions, memory and spontaneous thoughts, behave in different people, the authors said.

Jakubowski offered tips for how to get rid of an earworm:

• Engage with the song. Many people report that actually listening to the earworm song all the way through can help to eliminate having it stuck on a loop.

• Distract yourself by thinking of or listening to a different song.

• Try not to think about it and let it fade away naturally on its own.

Most frequently named earworms in study:

1. “Bad Romance” by Lady Gaga

2. “Can’t Get You Out Of My Head” by Kylie Minogue

3. “Don’t Stop Believing” by Journey

4. “Somebody That I Used To Know” by Gotye

5. “Moves Like Jagger” by Maroon 5

6. “California Gurls” by Katy Perry

7. “Bohemian Rhapsody” by Queen

8. “Alejandro” by Lady Gaga

9. “Poker Face” by Lady Gaga

{Light is not only a source of energy, but also an important signal which regulates many light-dependent growth processes in a plant in order to adapt it to its environment in the best possible way. Light is first detected by photoreceptors in the shoot of a plant. Physiological processes in the plant are mediated by light signaling molecules. For more than three decades, scientists have been speculating whether roots are also able to perceive light. However, this hypothesis could never be proved until this new study was published. “Physicists from Korea and biologists from Jena teamed and combined knowledge from both disciplines in order to find out, whether plant vascular bundles could act as light optical fibers and transmit light from the shoot to the roots,” Sang-Gyu Kim, one of the first authors of the study and co-initiator of the project, describes the successful cooperation.}

Previous studies had shown that a special photoreceptor in plants which detects light of the wavelength red/far-red is surprisingly also expressed in the roots. However, it remained unclear how this root photoreceptor was activated. In an interdisciplinary effort, molecular biologists and optical physicists developed a highly sensitive optical detector along with the idea to compare plants with “blind” and “sighted” roots. They used plants of the thale cress Arabidopsis thaliana, a model organism in plant research, which were genetically modified in a way that the photoreceptor was only silenced in their roots, but not in their shoots. Hence, these plants had “blind” roots. The scientists grew these modified plants along with control plants; their roots were in the dark soil and their shoots exposed to light, just like in nature. The optical detector system was used to measure light which was transmitted in the stem down to the roots. “With this approach, we could show clearly and without ambiguity that light is transmitted into the roots via vascular bundles. Even if the intensity of the transmitted light was low, it was sufficient to activate the photoreceptors, trigger downstream light signaling, and influence growth in the control plants,” Chung-Mo Park, the leader of the project at Seoul National University, explains.

“These results are crucial for further research projects. Our work proves that roots are able to perceive light, even though they are usually found belowground. Photoreception in the roots triggers a signaling chain which influences plant growth, especially the root architecture,” says Ian Baldwin, leader of the study at the Max Planck Institute for Chemical Ecology in Jena. He already looks into the future: “There are more photoreceptors in the roots. Until now, it has remained largely unknown what their responsibilities in the roots are and how they interact with light signals which are transmitted from the shoots.”

It is of major importance for ecological research to show the relevance of this study for plants growing in their natural habitat. To find out, the scientists want to perform experiments with another plant species, the coyote tobacco Nicotiana attenuata, a model plant in ecology, which is adapted to an extremely strong exposition to light. The researchers propose that the newly found sensory modality of roots is enhancing the ecological performance of plants in nature, by allowing for a better timing of resource allocations for growth, reproduction and defense.

{Positive school climates contribute to academic achievement and can improve outcomes for students from low socioeconomic backgrounds, according to a new study published in Review of Educational Research, a peer-reviewed journal of the American Educational Research Association.}

In a comprehensive analysis of research published since 2000, U.S. and Israeli researchers found substantial evidence that schools with positive climates can narrow achievement gaps among students of different socioeconomic backgrounds and between students with stronger and weaker academic abilities.

Broadly speaking, positive school climates are marked by a supportive, caring approach from teachers; a sense of safety from violence and bullying; student connectedness in school; and parental involvement.

“Our analysis of more than 15 years’ worth of research shows that schools do matter and can do much to improve academic outcomes,” said study co-author Ron Avi Astor, a professor of social work and education at the University of Southern California. “Our findings suggest that by promoting a positive climate, schools can allow greater equality in educational opportunities, decrease socioeconomic inequalities, and enable more social mobility.”

The analysis also found no correlation between socioeconomic status and perceptions of school climate. This suggests that schools serving students of lower socioeconomic status do not necessarily have poor climates and that positive climates can be nurtured in these schools.

“Positive school climate has the potential to break the negative influences that stem from poor socioeconomic backgrounds and to mitigate risk factors that threaten academic achievement,” said co-author Ruth Berkowitz, an assistant professor of social work at the University of Haifa, Israel. “Evidence-based interventions that support and improve school climate are critically important to efforts around the world to increase educational opportunity for disadvantaged students and schools.”

For their study, Berkowitz, Astor, and study co-authors Hadass Moore of the University of Southern California and Rami Benbenishty of Bar-Ilan University analyzed 78 studies published between 2000 and 2015 that focused on the relationship between school or classroom climate, academic achievement, and socioeconomic status.

Need for Common Definition and Measurement

In their analysis, the authors also found great variation in the school climate definitions and measurements used by researchers, reflecting the absence of clear and uniform standards.

“This becomes very important with the new Every Student Succeeds Act, which focuses heavily on the climate and social and emotional tone of schools,” said Astor. “The U.S. Department of Education has a definition and instrument that is only somewhat aligned with the research and the scholars producing it.”

“There is a tangible, immediate need to construct a common definition and reliable climate measurements that can be translated into practice and policy guidelines,” Astor said. “In the absence of a clear and uniform definition and measurement of school climate, the ability of researchers and stakeholders to evaluate school climate growth over time is restricted.”

Call for More Rigorous Research

In addition, the study authors made several recommendations to improve future research that would provide more definitive results and allow researchers to offer clear recommendations for policymakers and education practitioners. They strongly recommended the use of more rigorous research designs such as longitudinal, experimental, and semi-experimental.

They also recommended investigating an entire school community’s perceptions of school climate — including those of teachers, administrators, and parents — not just of students or teachers. In addition to allowing for more accurate evaluations of school climate, a multi-perspective approach would allow school communities to design their own climate improvement programs, tailor-made to their requirements and social and organizational characteristics, rather than importing external models that have proved effective elsewhere.

The authors also suggested examining the contribution of school climate to the arts, physical education, social and emotional learning, civics, vocational subjects, and other areas outside the core subjects of mathematics, language arts, and science.

{Climate change is currently one of the greatest threats to biodiversity, and one of the groups of animals most affected by the increase in temperature is amphibians. A team of scientists with Spanish participants studied how heat waves affect the dietary choices of three species of amphibian found on the Iberian Peninsula: the European tree frog, the Mediterranean tree frog and the Iberian painted frog.}

Global warming is causing not only a general increase in temperatures, but also an increase in the frequency and intensity of extreme weather events, such as flooding, heat waves and droughts. These environmental changes pose a challenge for many organisms, among them amphibians, who have to change their behaviour, physiology and life strategies in order to survive.

Researchers at the Universities of Lisbon (Portugal) and Uppsala (Sweden) studied the behaviour of three kinds of amphibians that inhabit the Iberian Peninsula: the European tree frog (Hyla arborea), the Mediterranean tree frog (Hyla meridionalis) and the Iberian painted frog (Discoglosus galganoi) to find out what effect heat waves can have on their diets.

As Germán Orizaola, co-author of the study published in the journal Ecology and a researcher at the Swedish university states “Among the many challenges climate change poses to natural ecosystems, the effect it can have on the dietary preferences of living organisms is a field of study that has been attracting researchers’ attention in recent years.”

Amphibians are a group that is highly sensitive to global warming due to the permeability of their skin and their complex lifecycle, which combines an aquatic stage as larvae and a terrestrial stage when young and as adults. “In fact, they are already experiencing sharp declines in population and extinction on a global scale, and they have become the focus of several research and conservation programmes in recent decades,” the scientist explains.

A vegetable-based, animal-based or mixed diet

The researchers conducted a laboratory experiment in which they exposed the larvae of these three species to various kinds of heat waves, which varied in duration and intensity, by increasing the temperature of the water where they were growing.

“The larvae were kept in three different sets of conditions: with a solely vegetable-based diet, solely animal-based or a mixed diet. This third situation allowed us to assess whether they modified their diets towards a greater or lower percentage of vegetable matter,” Orizaola adds.

They also examined the relationship between various carbon and nitrogen isotopes in the tissue of larvae with a mixed diet and compared them with those of exclusively vegetable-based or animal-based ‘menus’. This enabled them to reconstruct the type of diet larvae exposed to a combined diet selected..

“Our results indicated first that larvae of various species have a diet adapted to the conditions under which they reproduce. The painted frog, which reproduces when it is cold, has a carnivorous diet, while the Mediterranean tree frog, which reproduces during the hottest season of the year, maintains a vegetarian diet,” the investigator notes.

The most important result is that these larvae have very flexible dietary habits. All three species increased the percentage of vegetables consumed during heat waves. By analysing these larvae’s rates of survival, growth and development, reduced effectiveness of the carnivorous diet in favour of a vegetarian diet was discovered in hot conditions.

“This phenomenon could be common to many species living in continental, aquatic environments. If so, the increased frequency and intensity of heat waves forecast by climate change models could bring about considerable changes to these environments,” Orizaola concludes.

{New study has found two olfactory receptors in human lung tissue.}

It was always thought that olfactory receptors’ sole bodily function was to smell, and could only be found inside a nose. But now a new study, published in Frontiers in Physiology, has found two olfactory receptors in human lung tissue.

And when the researchers from Ruhr-University Bochum in Germany activated these receptors, they found that they regulated the way in which the airways smooth muscle cells contracted.

Contraction of smooth muscle changes the size of our airways, suggesting that this research may open new avenues for treating chronic breathing disorders — such as asthma, emphysema and bronchitis — that constrict and obstruct the airways.

No one had previously suspected that olfactory receptors would be present in airways past the nasal cavity. But working with human smooth muscle cells isolated and grown from the healthy parts of airway tissue surrounding excised tumors, Benjamin Kalbe and his colleagues applied a large number of odor molecules and watched two of them activate the muscle cells.

Because it is well established which odors activate which receptors, Kalbe and team were able to probe tissue biopsies look for two specific receptors — OR1D2 and OR2AG1, finding found both of them lying along the bronchi — the tubes that branch off from the trachea into the lungs.

Kalbe and co-workers then determined how activating the receptors with the odor molecules affected the isolated smooth muscle cells. First, they investigated the biochemical pathways triggered. There were no surprises here; what they saw echoed what happens in odor-sensing nasal cells when the receptors are activated, and the two different receptors seemed to act in an identical fashion.

Then, however, they did the key experiments. The primary function of a smooth muscle cell is to contract and relax. Yet, it’s difficult to know exactly how this process will be affected by a drug.

“We had no predictions when we looked at contractility;” says Kalbe. “At the beginning of the experiment we did not expect that the olfactory receptors would have completely different effects.”

But that’s what happened. Activating OR1D2 made the muscle cells contract, whereas activating OR2AG1 with a compound called amyl butyrate did not. Amyl butyrate wasn’t, though, simply inactive.

It’s well known that histamine makes airway smooth muscle cells contract. But when amyl butyrate was given before histamine, the muscle cells did nothing.

Extrapolating to intact airways, these results suggest OR1D2 activation would constrict the bronchi, whereas stimulating OR2AG1 might help prevent airways from closing in response to pathological triggers.

In addition, OR1D2 activation caused pro-inflammatory chemicals to be released from the muscle cells, whereas OR2AG1 did not.

Kalbe suspects that unravelling why the receptors have different end-results on smooth muscle contraction will be difficult. But he is excited about potential therapeutic applications. He says, “The best way would be to use a substance like amyl butyrate to support therapeutic intervention for patients with common airway diseases. Amyl butyrate […] might be a relaxing substance.”

To further explore the therapeutic potential of these receptors, Kalbe says his team are planning to obtain tissue from people with chronic airway diseases to compare them to healthy tissue, to observe if the receptors change in abundance or function in disease states.

Another mystery is what normally triggers the activation of these receptors — whether they usually respond to molecules that arrive in inhaled air or if the body itself makes signaling molecules that regulate smooth muscle via these receptors.

Regardless, sniffing out this unexpected function of an olfactory receptor may inspire exciting new medical developments.