Hi, we're here from curiosity.com to help you get smarter in just a few minutes.

I'm Cody Gough.

And I'm Ashley Hamer.

Today, you learn about how scientists stimulated mouse neurons to make them see things that weren't there.

You'll also learn about how mosquitoes have literally shaped human history,

from today's guest, Dr. Tim Weingard.

Let's satisfy some curiosity.

Scientists have stimulated mouse neurons to make them see things that weren't there.

And the results of this experiment could teach us about how our own brains work.

For some context, there's a lot we don't know about how the brain goes about perceiving the world.

For example, we know that certain neurons fire when you see a flower.

But are those neurons making you see the flower?

Or are they just firing in response to the visual cue?

That's the million dollar question.

And for this study published in August 2019,

Stanford researchers came up with a way to answer it.

Usually, scientists use a technology called optogenetics to activate individual neurons.

That involves introducing brain cells with foreign genes that code for light responsive proteins. Those in turn let

you activate those cells using carefully targeted doses of light. Yes, you heard me right, researchers

can stimulate neurons using light.

This Stanford team introduced the neurons with a new gene from a microscopic marine

organism to help them make more precise measurements than what you usually find in optogenetics.

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