In all cases, the animals are thought to be able to sense the chemicals people emit through body odor or breath. The combination of chemicals can vary depending on a person’s metabolism, which is thought to change when we get sick. But training and caring for dogs is expensive.Making a device that mimics a dog’s nose has proven extremely difficult, says Debajit Saha, one of the scientists behind it Latest workswhich has not been peer-reviewed.
“These changes are almost parts per trillion,” said Saha, a neuroengineer at Michigan State University. This makes them difficult to accept, even with the most advanced technology, he added. But animals have evolved to account for this subtle change in smell. So he and his colleagues decided to “hijack” animal brains instead.
The researchers chose to work with locusts because these insects have been well studied in recent years. In a preliminary setup, they surgically exposed the brain of a live locust. Saha and his colleagues then inserted electrodes into brain lobes that receive signals from the insects’ antennae, which they use to sense odors.
The team also grew three different types of human oral cancer cells, as well as cancer-free human oral cells. They used a device to capture the gases released by each cell type and deliver each of those gases to the locust’s antennae.
The locust brain responds differently to each cell type. The recorded electrical activity patterns were so distinct that when the team sprayed gas from one cell type onto the antennae, they could correctly identify whether the cells were cancerous or not from the recordings alone.
Saha said this is the first time live insect brains have been tested as a tool to detect cancer.
Natalie Plank, who is developing nanomaterial-based health sensors at Victoria University in Wellington, New Zealand, calls the work “really cool”. “Just being able to breathe something and know if you’re at risk for cancer … is really powerful,” she said.
In the experiment, the team took brain recordings from multiple locusts and combined their responses. Currently it requires recordings from 40 neurons to get a clear signal, which means the system requires between 6 and 10 locust brains. But Saha hopes to use electrodes that can record more neurons, which would allow him to take recordings from the brains of individual locusts. He also wants to be able to use the brain and antennae in a portable device, which can then be tested on real people.