In all cases, animals are thought to sense chemicals emitted by humans through body odor or breath. The combination of chemicals can vary depending on the person’s metabolism, which is thought to change when we get sick. But dogs are expensive to train and guard. And making a device that mimics a dog’s nose has proven to be extremely difficult, says Debate Saha, one of the scientists behind it. latest workwhich has not yet been reviewed.
“These changes are almost in parts per trillion,” says Saha, a neuroengineer at Michigan State University. That is why it is difficult to pick them up even with the most modern technologies, he adds. But animals have evolved to interpret such subtle changes in odors. So he and his colleagues instead decided to “steal” the animal brain.
Researchers decided to work with locusts because these insects have been well studied in recent years. In the preliminary setting, they surgically exposed the brain of a live grasshopper. Saha and his colleagues then inserted electrodes into lobes of the brain that receive signals from insect antennae, which they use to sense odors.
The team also bred three different types of human oral cancer cells, as well as human mouth cells that were cancer-free. They used a gas capture device emitted by each of the cell types and delivered each of them to the locust antennas.
The locust brain reacted differently to each cell type. The recorded patterns of electrical activity were so different that when the team blew gas from one type of cell onto the antennas, they could accurately identify whether the cells were carcinogenic based on the image alone.
This is the first time that the brain of a living insect has been tested as a tool for detecting cancer, says Saha.
Natalie Plank, who is developing nanomaterial-based health sensors at the University of Victoria in Wellington, New Zealand, thinks the job is “super cool”. “The potential of simply inhaling something and then finding out if you’re at risk for cancer is really powerful,” she says.
In the experiment, the team took brain scans from several locusts and combined their responses. Currently, images from 40 neurons are needed to get a clear signal, which means that the system needs between six and 10 locust brains. But Saha hopes to use electrodes that can record with multiple neurons, which would allow him to get images from the brain of a single locust. He also hopes to be able to use the brain and antennas in a portable device, which could then be tested on real people.