Despite the lack of speech abilities, animals still communicate. No language or gestures, but they give each other aware of the danger, sexual arousal or aggressive mood. Most communication between animals occurs at the level of the olfactory — they "talk" to their noses and secretory glands.
Animals, including mammals, unwittingly, give their aggressive mood and sexual arousal aromatic chemicals — pheromones. Pheromones also convey information about health, genetic usefulness and hierarchical status animal. Infox.ru wrote about how termites inhibit sexual activity in genetically abnormal females. In general, the molecular, cellular and neural mechanisms of communication in the language of pheromones have been studied enough.
Ear nose instead
Olfactory system is composed of several units — sub-systems that are different from other groups (populations) of sensory neurons with unique sensory connections. Each olfactory neuron has chemoreceptors that are sensitive to a particular class of compounds. The olfactory receptor (OR) — is a long protein molecules, which are embedded in the dendritic outgrowth of a neuron and pierce it several times. Going beyond the cell, they bind to specific compounds, and provide information to the olfactory center of the brain. And thence comes the response. It is for such a scheme, there is a "communication" between the animals themselves.
Scientists from the University of Idaho (University of Idaho), and the University of Saarland in Hamburg (University of Saarland School of Medicine in Hamburg), under the direction of Steven Myungera (Steven D. Munger) studied olfactory receptors in mice. Conducted an experiment they tried to explain the known fact that mice prefer to have relatives nadedennuyu food. That is, they are wary of food that smells just food. If the feeder is right for each mouse, its tribal kinsman more likely to also come to the same trough. In the study, researchers have paid attention to the receptors that provide social communication between animals. The experimental results have appeared in the article «An Olfactory Subsystem that Detects Carbon Disulfide and Mediates Food-Related Social Learning', published Friday in the journal Current Biology.
Experiments on friends
On the example of biologists studied rodent olfactory receptors GC-D, CNGA3 and GC-D+OSNs. Observations offer pet food that smells (or smell) other mice. In the experiment, researchers first studied the reactions of mice guessed by carbon disulfide (CS2) — Compounds that smell from the mouth of rodents. Theoretically, it could attract the attention of the animals to nadedennoy food.
As a result, the experimenters found that the receptor GC-D+OSNs is extremely sensitive to carbon disulfide. Rodent receptors respond to the substance, even if the concentration in the air do not exceed the micromole per liter.
Biologists say that rodents perceive related odor if it is coming from the food, even if there is no other animals nearby. Such a signal, most likely, at the molecular level convinces mouse that food is safe at least, because it has already tried another mouse is not dead.
"Mouse sniffs a piece and smells of his neighbor. She sees that her "friend" was killed by trying to write, because there is nowhere near the corpse. This is most likely, and convinces the animal that the food is not poisoned, "- says Stephen Myunger.
The researchers decided to see how the animal will react to smells if damage receptor GC-D+OSNs. It was found that rodents with modified (non-functional) olfactory receptors showed no preference in food and did not take the smell of carbon disulfide as a social signal. Researchers concluded that the receptor GC-D+OSNs recognize social aromasignaly and shapes food preferences in mice. According to the authors, this mechanism provides a social contact between rodents and reduces the likelihood that the animal stepped on the rake, which already ran one of the neighbors.