Sick animals recognize relatives by smell and are protected from contamination

SL, Понедельник 24 Сентябрь 2018 - 18:04:10

The smell of disease? Many may be the Association with the "hospital" smell of different drugs.

But as it turned out, the olfactory system of humans and animals capable of catching and more subtle flavors that are "misleading" about the health of other individuals of the same species. We are talking about the so-called bodily odors – organic, not obvious at first glance (or rather, nose).

A team of researchers from the Center for the study of chemical smells Monella in the US previously found that inflammatory processes in the body lead to changes in the organic odors of the body. In other words, "immunoactive" odors can signal the presence of the risk of infection.

Now scientists have shown that the body odors of healthy animals that are in the same environment with sick animals, change as well. It is not excluded that the same is true for people. It is possible that such biological signals may affect social contacts, and even affect the spread of the disease.

"The effects of odors sick people can provoke protective responses from their social partners, to minimise the risk of an impending infection," explains lead author Stephanie Gervasi (Stephanie Gervasi).

The experiments she and her colleagues injected mice with non-infectious bacterial toxin called lipopolysaccharide. It causes inflammation, activation of the immune system and other "canonical" symptoms of the disease.

Then these rodents were placed in cages to a healthy one. The last pre-trained to distinguish odors of urine "patients" and healthy relatives.

The results of bioassays of mice-"sniffer dogs" have shown that their body odour changed and became more like the smell of "sick" mice than healthy.

The data confirmed and specially created a predictive model that analyzes the ratio of "fragrant" chemical compounds in the urinary bladder of animals. According to this model, healthy mice cohabiting with "sick", you'll find more connections typical of "sick."

Even when the researchers repeated the experiment but added to the cage wall with small holes, the results have not changed. The baffle did not interfere with the circulation of smells, and healthy mice continued to receive chemical signals from the "sick" colleagues.

"This work shows not only that the smells indicate the disease, but also that they can have a strong impact on those in their catches. This amazing process of transmission through the olfactory information that alters physiology and can play a role in the transfer of disease among the animals of many kinds," — said the co-author of work behavioral biologist Gary Beauchamp (Gary Beauchamp).

The study also showed that the smells that are associated with disease in healthy animals trigger a cascade of reactions – neuroendocrine and immune responses that protect the body from potential threats.

According to the authors of the work published in the journal Scientific Reports, the new data will be useful to ecologists who are engaged in maintaining populations in the wild.

It is also likely that new research will help to identify the transmission of "alarm odors" affects the spread of disease among the people. Previously, for example, the authors of the project "Conduct.Science" (nauka.vesti.ru) reported that people are able to detect a peculiar odor in the sweat of another person with a high immune activity. But the experiments with the same lipopolysaccharide showed that we, like animals, can detect by smell the presence of "disease."




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