1. The worm is 1 mm long and few hundred microns across.

2. It has a fully characterized nervous system - 302 well defined neurons that have been mapped and named in exquisite detail. We even know which neurons connect to which! Have for decades. Still can’t tell how they function though.

3. The authors are expressing optogenetics proteins in various sets of neurons. Line 1 expresses them for example in 8 neurons known to play a role in chemotaxis (moves towards food).

4. They just shine a flash of light on the worm which would activate all these neurons together. This is probably still as blunt as putting an electrode into a mouse or monkey brain in some rough area and zapping them. I was hoping for slightly precise control.

I’ve been waiting for optogenetics to enter worms - mainly because they’re like the cheapest and easiest to work with creatures and I always believed understanding the simplest organism first is the right way to understanding any complex system.

Basically they took a worm and hijacked the genetic machinery such that a subset of neurons could be activated or inhibited via a light sensitive protein.

Then they hooked up an unsupervised RL algorithm to a camera, and it learned how to control the lights to direct the worm towards a goal like food.

The learned algorithms were able to navigate obstacles and generally enhanced the capability of the worm while coexisting with the remaining uncontrolled neurons.

www.michaelblumlein.com/miscellany/knowhowcando_blumlein.pdf