Tag Archives: nose

Is your dog’s nose cold and wet or warm and dry? Both are normal

Credit: Pixabay.

Most dog owners love to play and snuggle with their canine pets. Inevitably, these petting sessions often involve your dog licking your face or bumping their nose on your skin. Their snoot can feel cold and wet, other times it might be warm and dry. This may make some dog owners wonder: is it normal? Should I talk to a vet?

According to researchers from Eötvös Loránd University in Budapest, Hungary, both wet and dry noses are normal.

A dog’s nose will typically be warm and dry when they sleep. Immediately after they wake up, dogs lick their nose, which becomes cold and wet.

Previously, some have proposed that a dog’s cold nose helps canines regulate their body temperature. However, a dog’s nose is too small relative to their body size to offer any tangible advantage in terms of thermoregulation.

Another hypothesis that might explain the wetness of canine snouts suggests that a cooler nose aids carnivores in detecting prey. Anna Bálint and colleagues at Eötvös Loránd decided to investigate this latter hypothesis and measured the temperature of various dog noses, as well as those of horses and mooses.

Thermograph of a dog in the shade at 27 °C ambient temperature. The colour scale on the right is in °C and can be used to read out approximate temperatures. Note the warm tongue and the cold rhinarium (hairless nose tip). Credit: Scientific Reports.

In one experiment, the researchers trained three pet dogs to choose a warmer object, which had about the same temperature as a potential prey, over an object at room temperature. This suggests that a dog’s nose is indeed capable of detecting heat from relatively distant prey, even if the thermal radiation is weak.

“The ability to sense weak thermal radiation has the potential of conveying valuable sensory information to an animal preying mainly on endothermic animals. The ability to sense such radiation is known in insects (Black fire beetle, Melanophila acuminata), reptiles (certain snake species: Crotalinae, Boidae) and one species of mammal so far, the common vampire bat, Desmodus rotundus), which can detect skin areas richly perfused with blood and thus suitable for biting after landing on a host anima,” the researchers wrote.

After this behavioral trial, the researchers also performed a neural experiment to see what happens inside the brain when a cold nose is engaged in heat detection.

The researchers placed 13 dogs inside a functional MRI scanner and analyzed their brain waves as the canines were presented with a box containing warm water and an insulating door. When the insulating door was open, the dogs’ brains had a higher response in the somatosensory association cortex, a brain region that processes various sensory stimuli.

Taken together, the authors claim that the findings suggest that dogs and other cold-nosed animals employ heat detection in their hunting routines, in addition to their already keen sense of smell.

The findings appeared in the journal Scientific Reports.

Nosy study finds we probably produce new neurons all the time

New research suggests that humans may actually be able to create new neurons after childhood. The paper reports on a new “neuron nursery” located in a section of our noses.

Human olfactory neuroepithelium.
Image credits Duke University.

The study was published in the context of a much wider (and long-lasting) debate on whether humans are able to create new neurons after the age of 13. Neurons, the ultra-specialized cells that underpin our nervous systems, aren’t only useful for thinking or telling muscles to move. The current study focuses on neurons that act as receptors in the olfactory neuroepithelium of the nose. These neurons directly underpin our ability to smell.

Smells brand new

“We do not fully understand why people lose their sense of smell, which can occur for many reasons, and our data sets provide a wealth of information about the cell populations present in adult olfactory tissue,” said Brad Goldstein, M.D., Ph.D., an associate professor and vice chair for research in the Department of Head and Neck Surgery and Communication Sciences at Duke University and senior author of the study.

“This is an important step in developing treatment strategies for conditions when this tissue may be damaged.”

This study is the first of its kind to use human tissue samples (previously only mice nasal tissue samples were used). Starting from them, the team found that immature neurons being produced by stem cells made up over half of the number of neurons in the samples, suggesting that they were actively being produced there. Which, obviously, means that neurons can be produced throughout our lifetime.

Hiroaki Matsunami, Ph.D., a professor in the Department of Molecular Genetics and Microbiology at Duke University and co-author on the paper, explains that the molecular make-up of these immature neurons point heavily to them being grown there during adulthood.

The team says that their findings could help guide treatment options for conditions that cause smell damage or loss, but could in time be applicable to the nervous system as a whole.

“It will be very useful to use this window to analyze samples from people with conditions in which the nervous system has degeneration, such as Alzheimer’s disease,” said Goldstein.

“Alzheimer’s is of particular interest, since these patients lose their sense of smell quite early in the disease process, and we have few treatments for Alzheimer’s disease. So, it may make sense to look carefully at regions of the olfactory system in these patients.”

The nose is a very exposed site, the team adds, meaning that in time we could learn how to collect neuronal stem cells from the area and use them to treat other disorders involving the nervous system.

“It is not outside of the realm of possibility,” said Matsunami.

The paper “Single-cell analysis of olfactory neurogenesis and differentiation in adult humans” has been published in the journal Nature Neuroscience.

Why selfies make you hate your nose

A new study has found that selfies make noses appear 30% larger — and people aren’t happy about it

Selfies are changing the way we see ourselves — both figuratively and literally.

The selfie effect

With the explosion of social media, people are taking billions of selfies every day and posting them to different channels. Social media has become an important part of our lives, with many people changing the way they look and act in response to this phenomenon. Boris Paskhover, an assistant professor at Rutgers New Jersey Medical School’s Department of Otolaryngology who specializes in facial plastic and reconstructive surgery, realized that people want to change their appearance to improve their social media persona — even if that means plastic surgery. Many of the people who were asking him for plastic surgery showed selfie examples, prompting him to investigate this further.

“Young adults are constantly taking selfies to post to social media and think those images are representative of how they really look, which can have an impact on their emotional state,” he said. “I want them to realize that when they take a selfie they are in essence looking into a portable funhouse mirror.”

The American Academy of Facial Plastic and Reconstructive Surgeons has also noticed the trend. According to a 2017 poll, 55% of facial plastic surgeons reported seeing patients who wanted surgeries to make them look better in selfies, up from 13% in 2016.

Strangely, many of the people who wanted to change their noses had rather normal features.

“I’d say, ‘Your nose doesn’t look big — there’s distortion when you keep a camera close to your face,” Paskhover recalled.

An unexpected effect

Portrait A is taken at 12 inches; portrait B is taken at 60 inches. Credit:
Boris Paskhover

In order to better understand this, he teamed up with Ohad Fried, a research fellow at Stanford University’s Department of Computer Science. They developed a mathematical model which describes how photos taken at very short range (such as selfies) distort people’s opinions about their noses.

They found that when the lens is very close to the face, at about 30 cm (12 inches),  it makes the nose look about 30 percent larger compared to the rest of the face.

It’s all about perspective. Think about it this way: when you’re close to a building, it seems very large. But the more you step back, the smaller it seems. To the lens, your face is essentially a plane perpendicular to the main camera axis, and the nose is coming out of that plane. Due to this geometry, the closer the lens is too your face, the larger the nose seems relative to your other features.

Paskhover says that given how selfies drive people’s self-image, this should be considered a public health issue. What do you think?

Journal Reference: Brittany Ward, Max Ward, Ohad Fried, Boris Paskhover. Nasal Distortion in Short-Distance Photographs: The Selfie EffectJAMA Facial Plastic Surgery, 2018; DOI: 10.1001/jamafacial.2018.0009


The smell organ as illustrated by Frank R. Paul in the June 1922 issue of Science and Invention.

Music for the nose: an olfactory organ

The smell organ as illustrated by Frank R. Paul in the June 1922 issue of Science and Invention.

The smell organ as illustrated by Frank R. Paul in the June 1922 issue of Science and Invention.

There’s a whole science behind scents. The perfume industry is worth billions and scientists all over the world, mostly in corporate laboratories, work each day to find the perfect balance between odors. In many respects, perfumery is regarded as an art of its own, and some have even drawn comparisons to music.

Dr. Septimus Piesse, a French chemist and perfumer who wrote the 1857 book The Art of Perfumery, was famous in his time for his theories that loosely compared music and how certain smells work together.

Just like an arrangement of musical notes fly together to create a spectacle for the ears, so can an array of various scents blend to enlighten the nose. Oppositely, when music goes wrong and leads to dissonance, so can some smells go horribly wrong together.

With this in mind, a 1922 issue of the magazine  Science and Invention presented a concept instrument meant for the nose, not for the ears.

The authors envisioned a “smell organ” where the artist would shoot scents instead of musical notes and dazzle his audience. The smell organ even has a whole theory behind it, as the authors envisioned  “heavier” odors assigned to lower notes, and “sharper” odors assigned to higher notes. The authors even illustrated notes that would correspond to which fragrances.

Small organ keys

The article reads:

“Of course, the combination of these odors will create a smell entirely different from any of the individual qualities of the various perfumes and it is necessary that, in the soft, dreamy compositions, the odors blend harmoniously. Discords will have a decidedly unpleasant effect but inasmuch as the composers did not dwell upon discords to any great extent, the audience will be saved the rather unusual embarrassment of smelling disagreeable combination. Some music, would perhaps have to be changed and the odors carefully graduated so that in the smells wafted over the audience no particular perfume will predominate, except when the loud pedal, or rather, in these smell organs, the strong odor pedal is trod upon.”

“It is, therefore, up to the perfumer to combine the mixtures in much the same way as an artist blends colors, or as a good florist makes up his bouquet. If it is desirable to insert a little contrast into the bouquet, the appropriate blossoms or grasses are used, and so the perfumer, likewise would have to employ the proper aromas.”

If you think a bit about it, it sounds like a brilliant idea. Imagine being in the front row of the concert hall where the olfactory organ concert is swinging away. It wouldn’t be too exciting, but if joined with images or music, preferably both, uplifting sensations might touch you.

A concert could explore the four seasons with all the odors that come with each or the story of a journey at sea told through smell. Avant-garde artists would surely throw the most peculiar odor side-shows.

Would such an instrument be possible? Well, unlike musical notes which are actually vibrations, smell doesn’t dissipate nearly as quickly. The range of emotions that one can touch over a period of time is thus very limited in the case of a smelling organ. Maybe by using an intelligent, localized venting system that can’t be felt by the audience would make such a feat possible.



White Nose Bat Syndrome spreads deeper into the U.S. — first case confirmed west of the Rockies

The first case of white nose syndrome, a disease that has wreaked havoc on bat populations in the eastern U.S. has been identified west of the Rockies. The disease’s spread threatens to drastically impact bat populations there, altering ecosystems throughout the country.

Hikers discovered a little brown bat with white nose syndrome on a trail east of Seattle last in mid-March this year, the Department of Fish and Wildlife and the U.S. Geological Survey announced on Tuesday. This marks the first incidence of the deadly fungus west of the Rockies. The ailing bat was taken to an animal shelter, where it died two days later.

Picture of a little brown bat with white nose syndrome, taken in New York state, Oct 2008.
Image credits to U.S. Fish and Wildlife Service Headquarters.

USGS National Wildlife Health Center’s Wildlife Disease Diagnostic Laboratories branch chief David Blehert thinks it’s “surprising and unusual” to find the fungus spread this far west — the closest the syndrome has been identified before was Nebraska, some 1,300 miles from the site.

 “We’ve been dreading this,” said senior scientist at the Center for Biological Diversity Mollie Matteson in an interview for The Huffington Post. “This is a drastic jump.”

“This is the first time, to our knowledge, that there has been a long-range jump of the fungus,” Blehert said.

Caused by the fungus Pseudogymnoascus destructan, white nose syndrome can wipe out entire bat colonies. It gets its name from the white fuzzy fungal growths on the noses, wings and ears of affected bats. The devastating disease spreads throughout bodily tissue, disrupting physiological processes and interrupting essential hibernation periods, causing bats to waste away.

It has already caused the deaths of more than 6 million bats in the eastern U.S, in what some describe as the steepest decline or North American wildlife of the past century.

Seven different species of cave hibernating bats in 28 U.S. states and five Canadian provinces have been affected by white nose syndrome since 2006, when the first case was recorded in upstate New York. Two of these species are native to Washington state.

“I wish I could be optimistic, but given what we have seen on the East Coast, it’s hard to,” said Sharlene E. Santana, assistant professor of biology at the University of Washington.

“We knew it was coming [to the West], but we didn’t know it would be so soon,” Matteson said.

Range of white nose syndrome.
Image credits Washington Department of FIsh and Wildlife.

Blehert’s analysis of the Washington bat revealed that the disease was at an advanced stage, suggesting it had been present in the area for quite some time. Genetic sequencing indicates that the animal is a native to the area.

“We don’t know how the fungus got there,” Blehert said.

The fungus could have been transported bat-to-bat — which would have taken an extraordinarily long time. Or, as Blehert suspects, through human travel and trade, one of the largest spreader of infectious diseases. Humans aren’t affected by the fungus but act as carriers and are believed to (unknowingly) play a central part in transporting the disease across the country. Hikers’ and spelunkers’ clothes and gear can transport the fungus, according to the researchers.

Little brown bat with white-nose syndrome in Greeley Mine, Vermont, March 26, 2009.
Image credits Marvin Moriarty/USFWS, via flirk.

Unfortunately there is no proven method to cure the disease or at least halt its spread.

“We had hope that by the time [white nose syndrome] started to spread to the West, that there were more effective treatments in place,” Matteson said.

Scientists are now looking into the genetic code of the fungus to determine its point of origin and try to set up precautions to halt its spread around the world — the fungus most likely arrived in the U.S. on a human carrier from Asia or Europe where it’s endemic. They’re also looking into creating a vaccine that could give the bats a fighting chance against white nose syndrome.

“For years, we have been saying there needs to be stricter protocol put in place to minimize the chance of a jump like this via human transmission,” Matterson added.

Authorities are now putting abandoned mines and caves under lock-down to protect resident bat colonies. Federal agencies encourage visitors to decontaminate themselves and gear before entering an area with bats, but Matteson argued decontamination should be mandatory.

“We have species that are at risk of going extinct; it’s the least that could be done.”

Bats are an integral part of an ecosystem, and scientists are concerned about the chain reaction their loss might have on plant and animal life, including humans. If the bat population declines, insects would thrive and devastate agricultural areas. Populations of disease-carrying insects would also be left unchecked.

However, there might still be hope. Because bats in the western U.S. tend not to hibernate in large groups, the disease might not spread as widely or quickly from bat to bat. But far less is known in general about how bats hibernate on the West Coast, Matterson said, which means the bats could already be dying.

“As the case in Washington indicates, the disease has already been there for a couple years, and it just got discovered this past month,” she added.

“One of the huge problems with white nose syndrome has been that the [government] response was slow to get off the ground, it was disorganized, a lack of leadership, there wasn’t any decontamination requirement for western public lands, no cave closures.”

“There will be more in the future,” she concluded. “We need to learn our lesson.”

Wildlife officials encourage people who encounter sick or dead bats to report it via an online reporting tool or telephone hotline, 1-800-606-8768.

pig love

Do pheromone perfumes work? Love at first scent is not that easy

With Valentine’s Day just around the corner, some of you might be tempted to employ some of those spray-on pheromone products. I won’t give names, but you must have seen the ads – they’re all over TV and the internet. Odorless pheromones are secreted by many animals to attract mates, and while synthesized versions have been shown to work for bees and other insects, the human nose and brain for that matter is a whole different thing.

Mammals of all sorts use olfactory signals to indicate willingness to copulate, define territory, mark their young, and signal aggressive intent. These processes can be seen in many animals used as models for human systems, including rats, monkeys (both Old World and New World), hamsters and mice. The fact that pheromones are important biological signals in a plethora of other species indicates that the possibility of human pheromones should not be discarded lightly. But this doesn’t mean those $100 bottles for 1/6  of an ounce actually work. Reactions is back this week with a great debunking on commercial pheromones. In short: no, these don’t work! Save your money for a nice dinner. You’ll have to impress your date the hard way.

The science of the cute nose: hot and cold

These infrared pictures show that some mammals keep their nose warm, while some keep them cold. Can you guess which of the noses below belongs to each animal? Oh, and more importantly, can you guess why their noses are hot or cold? You’ll find the answers at the bottom of this post.

ir animal noses rhinaria

Mammal Noses in Infrared. Via Lund University Mammalian Rhinarium Group

The pictures come from scientists at Lund University in Sweden, and it’s not just about curiosity or about taking nice pictures of cute schnozzes – they are actually studying a specialized mammalian nose structure called the rhinarium. The rhinarium is the moist, naked surface around the nostrils of the nose in most mammals. In actual scientific usage it is typically called a “wet snout” or “wet nose” from its moist and shiny appearance.

“We want to know what mammals can do with specialized nose tips,” Lund zoologist Ronald Kröger explains.

A cat’s rhinarium. Via Wiki commons.

Many mammals, like dogs, cats or deer have wet, hairless rhinaria – however, humans don’t. We like our noses dry. The consequence of this is that the nerve interiors of different noses are also almost certainly very different. Kröger and team is trying to find out what role do the rhinaria play in terms of temperature – in other words, what advantages do mammals have from having hot or cold noses.

Previously, he researched animal vision, but interestingly enough, he got curious about rhinaria when his dog touched him with its cold nose, which made him wonder about its unusual temperature.

“I thought, this is so interesting, we have to know more,” he says.

So far, the team hasn’t published any scientific papers, but they’re well on the way.

The animals above are:

Row 1: dog, horse, sheep, pig, cat, goat
Row 2: rhesus monkey, rat, kinkajou, rabbit, cow, degu
Row 3: zebu, ring-tailed lemur, meerkat, harbor seal, moose, raccoon dog
Row 4: polecat, arctic fox, lynx, raccoon, common eland, human


ir dog nose

Have a look at this dog’s nose as he falls asleep (top row) and then awakes (bottom row). Typically, dogs keep their noses wet a few degrees warmer than the rest of their bodies. However, when they rest, the nose becomes drier and warmer – only to get wetter and colder when they awake.

The Smell of Sound – how nasal stem cells treatment can prevent hearing loss

A research published earlier today in Stem Cells relates how stem cells scientists in Australia have managed to show that patients suffering from hearing disorders emerged during childhood could benefit from a stem cells procedure collected from one’s nose.

The research focused on early-onset sensorineural hearing loss, which is caused by a loss of sensory cells or neurons in the cochlea,  the part of the inner ear that holds the actual sensory organ of hearing. The condition can have genetic causes, often arising during infancy and childhood, hindering cognitive development and leading to speech and language problems.

“One of the challenges in tackling this condition is that the regenerative ability of the human cochlea is severely limited”, said lead author Dr. Sharon Oleskevich from the Hearing Research Group at The University of New South Wales. “It has been proposed that the transplantation of cells from other parts of the body could treat, prevent or even reverse hearing loss. The transplanted cells have the potential to repair tissue by replacing damaged cells and enhancing the survival of existing cells, preventing the condition from developing further.”

Research was conducted on mice that showed symptoms of hearing loss – these were injected with mucosa-derived stem cells into the cochlea of mice. Mice were chosen as they exert a similar decline in hearing after infancy, much like humans do.

“The authors have used an interesting type of adult stem cell, related to mesenchymal stem cells, to reduce the extent of hearing loss. Since the cells did not integrate into the cochlea, it is likely that the effects from the adult stem cells were due to the release of factors to preserve function of the endogenous stem cells. Mesenchymal stem cells are known to provide factors to keep many types of cells healthy and functioning,” said Jan Nolta, Associate Editor of Stem Cells.

One’s hearing capabilities is measured using an auditory brainstem response assay, which determines the lowest sound level to which the brain responds, known as the hearing threshold. After the stem cell operation, the mice with the transplanted nasal stem cells did better when compared to mice without

“The results demonstrate a significant effect of nasal stem cell transplantations for sensorineural hearing loss,” concluded Oleskevich. “These cells can be obtained easily from the nasal cavity making this transplantation a potential treatment for other human conditions including Parkinson’s disease and cardiac infarction.”