How do nematodes detect odors? 30-year-old mystery solved

A team of scientists from the University of Toronto Under the supervision of a. Derek van der Koe discovered the molecular mechanism behind the sense of smell in nematodes. Scientists have suggested that it is linked to a protein involved in the process of vision in humans. The research was conducted on nematodes Certain types are elegantTheir results were published in Proceedings of the National Academy of Sciences (PNAS).

Dr. Daniel Merritt, first co-author who worked in the professor’s lab. Derek van der Koe says:

Nematodes have an amazing sense of smell. They can detect a very wide range of compounds, such as particles from soil, fruits, flowers, and bacteria. They can even sense explosives and vital signs of cancer in patients’ urine.

The smell is perfect

nematodes Certain types are elegant They are widely known as organisms with an excellent sense of smell due to their 1,300 odor receptors. For example – people only have 400 of them.

Human noses are lined with hundreds of sensory neurons, each of which expresses only one type of receptor. When fragrance activates a neuron, the signal travels deep into the brain along its long section (the axon), where it is perceived as a scent. It is possible to distinguish odors by physical separation of axonal channels carrying different odor cues.

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However, nematodes only contain 32 olfactory neurons, which house all 1,300 receptors. How can nematodes detect the different odors that are sensed by the same neuron?

Dr. Merritt adds:

Clearly, the single-neuron odor strategy would not work in this case. It appears that all the information these neurons sense is compressed into a single signal, yet the nematodes can somehow distinguish between the components.

Scientists have suggested that nematodes sense not just the presence of a specific odor, but its intensity. Proteins called arrests play an important role in helping humans regulate vision in intense light by suppressing signals in the retina. In nematodes, the mechanism is similar, but with regard to odors. This is a very important finding that shows that stroke can regulate many different sensory impressions.

Dr. Merritt concludes:

In biology, there was no previously known case where capture was used to discriminate external signals of a cell. Our work offers not only one piece of the puzzle about how nematodes’ amazing sense of smell works, but also our understanding of how all signals work more broadly within animals.