Greg Neely

And so in that study, we turned off each gene that the fruit fly has one by one, just in their nervous system, in their brain, basically, and their sensory nerves.

And then we put them on a test to see if they could detect high temperature that could hurt them.

A bit like the cricket heat test.

And then we basically evaluated animals that could sense the temperature and ones that couldn't sense the temperature.

And it basically taught us all the basic machinery that's required for an insect to sense and avoid noxious temperature, so really high, dangerous temperature.

And that's similar to our pain sensation.

What is a noxious temperature to a fruit fly?

So anything above 44 degrees Celsius, probably.

It depends how long the time is.

So if you give them like a five minute window, then 44 degrees will knock them unconscious because it's so hot, it hurts them.

We basically injured one of their nerves going down their legs, which is basically like sciatica.

They let the injury heal.

And then we watched them...

Under normal situation, they didn't seem to show a lot of spontaneous escape behaviors.

So they were acting pretty normal.

But then when we put them on a higher temperature, then they would basically run around and jump, trying to escape the temperature, even though it's not hot enough really to harm them.

So an uninjured animal would just be cool with that temperature.

It was 38 degrees.

And an injured animal then thought that it was really dangerous.

So the very first thing is we share a common ancestor 550 million years ago, insects and humans.