Dr. Justin Feinstein

I felt fear.

I mean, if you could have been a fly on the wall in the laboratory that day, our eyes were wide open, our jaw was agape.

We were all dumbfounded because this was the exact opposite of what we had expected to happen.

You know, for the better part of a half a century, it was always presumed that the amygdala was required to feel fear, to feel panic.

And for the first time, we have a human who is lacking this structure in their brain, no longer has the amygdala, yet still felt fear and panic.

Where is this happening in the brain?

How is this happening in the brain?

These were the types of questions spiraling through my head.

So ever since this fateful day, I've been racking my brain to try to understand how is this happening?

Amazing.

Cells that are exquisitely sensitive to even small changes in carbon dioxide.

That's right.

Well, keep this in mind.

It sounds a little hyperbolic, but it turns out it's absolutely true.

If you breathe that level of CO2 for even one to two minutes, it could kill you.

This panic response, this alarm is a real alarm.

It's trying to alert you, essentially, that the pH of your blood is dropping.

It's becoming acidic.

And now your brain is saying, my goodness, where is all this CO2 coming from?

So when the CO2 hit the chemoreceptors of SN, those chemoreceptors fired like it was a firework show, right?