Hail hydra how to#

So genetically identical creatures do not have identical nerve nets. The slight wrinkle here is that how many neurons a Hydra has is not fixed: it depends on the age of the creature, and ranges from a few hundred to a few thousand. They can reproduce asexually by budding which creates a clone, so you have a set of practically identical individuals to record from. And all while the creature was wriggling around under the microscope.Īlso useful about Hydra, parts three and four. So by watching their videos they could work out each neuron’s activity in each frame of the video just by recording how green it was. They engineered their Hydra so that the Hydras’ neurons expressed a protein that emits green light in proportion to how active a neuron is.

Hail hydra how to#

The key then is to work out how to video not just the neurons, but the activity of those neurons.Ĭhristophe Dupre and Rafael Yuste did just that. That means we can video the neurons by simply videoing the animal (as we can see into the animal) and (as the neurons are all spread out) we can easily separate individual neurons when we analyse the video. And the other thing: it is completely see-through.

But all we care about are whether it has neurons that link together and control the creature, which it does). (Technically, this is cheating as Hydra therefore has no “brain”, just a “nerve net”. For one, all its neurons are spread throughout its entire body, not irritatingly grouped into clusters like in C.

A cnidarian, with whom our shared common ancestor is likely more then 500MYA a worm-like thing with tentacles, about 1cm long with two stunningly useful features. But that’s impossible: how can we find a creature with a tiny brain in which we can record and see every neuron?Įnter Hydra. So we need to aim at something, some creature, with a brain that’s a little more modestly proportioned.Īnd how will we know when we’ve recorded every neuron? Ideally because we can see every neuron we’ve recorded from. With around 86 billion neurons, understanding our brain is as far out of our reach as understanding quantum chromodynamics is to my cat Charlie (and he’s the smart one to Bob it’s as far as understanding how the cat flap works). In the absence of a theory telling us what we should be looking for, many believe the answer is: record everything. What’s the best way to understand a brain? A brain, any brain at all.