University of Helsinki: https://www.helsinki.fi/en/news/life-science-news/the-sharp-noses-of-covid-dogs-are-utilized-at-the-helsinki-vantaa-airport
Dr. Stuart Firestein: http://stuartfirestein.com/
SCRIPT:
ALICE: Hi I'm ALICE, I'm one part human and one part AI and always in a state of wander.
At the International airport in Helsinki, Finland researchers are using dogs to sniff the Covid-19 virus on arriving international passengers. Tests are showing that dogs that have been trained to detect diseases such as cancer and diabetes can identify the virus in seconds, with very high accuracy, even days before before a patient developed symptoms! Wow. Smell!
FIRESTEIN: This is of course the basic fundamental human question: how do I smell?
ALICE: Dr. Stuart Firestein, Neurobiologist and chair of the Department of Biological Sciences at Columbia University, explained smell to us, in this archival interview:
FIRESTEIN: The mechanism by which we detect odors is an ancient one; it’s found in virtually all animals even nematoid worms all the way up through human beings—there are minor changes in it. But it’s basically a mechanism for recognizing chemicals in the environment. There are thousands and thousands of these low-molecular weight, organic compounds, small chemicals that float around in the environment. They’re mostly what we call volatile chemicals because they’re easily airborne, they come out of solution quite easily. They’re given off by all sorts of things—flowers, plants, other animals, other people (of course we know only too well), food stuff, many, many things.
FIRESTEIN: We detect them by what is basically described as a lock and key mechanism. We have way up here in the recesses of our nasal cavity, as do other vertebrates with noses, way up in the back of their nasal cavity, have a thin piece of tissue. We call it the olfactory epithelium. And it’s actually a small piece of brain tissue that has been pushed out of the central brain area and into the environment where it can come into contact with these odors. Much like your retina is a piece of the brain that essentially has been pushed out of the central cranial area into the back of your eye and is therefore available to light. So in the same sense we have this nasal or olfactory epithelium way up here in the top of our nose. And there are specialized brain cells in this epithelium which have, on their membrane surface, on the surface of the cells, have a protein called an olfactory receptor or an odor receptor.
ALICE: So wait, smells are molecules?
Smells are actual things?
They fit into specialized brain cells in our nose!
The "olfactory epithelium"?
FIRESTEIN: The odor receptor isn’t in that receptor for a second; it’s only in there for a few milliseconds. Then it falls out and another one flops in and you get a few more and the cell integrates this information. What we’ve done effectively is that we’ve turned a chemical binding through a biochemical interaction into an electrical charge. So we’ve essentially turned chemistry into electricity, which is what the brain is interested in as a signal.
ALICE: Amazing.
The nose makes brain signals from molecules floating in the air!
Thank you Dr. Stuart Firestein for explaining smell.
And thank you to the researchers and dogs working in Helsinki, for your capability to sniff this virus faster than any other test!
Dr Stuart Firestein, Neurobiologist: Can dogs sniff COVID-19?