First Movie of an Entire Brain's Neuronal Activity 44
KentuckyFC (1144503) writes "One of the goals of neuroscience is to understand how brains process information and generate appropriate behaviour. A technique that is revolutionising this work is optogenetics--the ability to insert genes into neurons that fluoresce when the neuron is active. That works well on the level of single neurons but the density of neurons in a brain is so high that it has been impossible to tell them apart when they fluoresce. Now researchers have solved this problem and proved it by filming the activity in the entire brain of a nematode worm for the first time and making the video available. Their solution comes in two parts. The first is to ensure that the inserted genes only fluoresce in the nuclei of the neurons. This makes it much easier to tell individual neurons in the brain apart. The second is a new techniques that scans the entire volume of the brain at a rate of 80 frames per second, fast enough to register all the neuronal activity within it. The researchers say their new technique should allow bigger brains to be filmed in the near future, opening up the potential to study how various creatures process information and trigger an appropriate response for the first time."
80 frames/second (Score:5, Interesting)
If that captures everything, that's the interesting part to me(though I'm sure it's been known to actual neurologists forever). That means the "clock speed" of the human brain is really really really really low, more or less, right? Like our consciousness is pretty much exclusively the result of massive parallelism?
Re:Mapping the Nematode? (Score:4, Interesting)
Why wouldn't it be? Light-sensitive proteins are quite well understood.
All of this leads to a really fascinating possibility down the road...
Part 1: Requirements:
1) Genes are inserted into the nucleus of every neuron.
2) Probes which can receive on one or more optical frequencies** and send directionally on other frequencies (which we'll call A, B, and C) are inserted all throughout the target brain.
3) The genes from #1 flash upon synapse**, allowing the probes in #2 to receive the signals
4) The genes from #1 force a synapse when they receive frequency A from a probe.
5) The genes from #1 suppress synapse when they receive frequency B from a probe.
6) The genes from #1 force the cell to commit apoptosis when they receive frequency C from a probe.
Part 2: For each neuron in the brain (conducted in parallel):
1) The neuron's behavior is studied relative to its neighbors in order to learn precisely what factors control its activation levels. This requires a very accurate neural model, and probably requires a lot more more than a simple one-frequency "I'm firing" signal in #2 and #3 of part 1.
2) The neuron is simulated in a computer based on said inputs
3) The neuron is ordered repressed when the simulator doesn't want it fired, and ordered fired when the simulator wants it fired.
4) The system works its way through all of its neighbors that it influences, doing steps #1-3 of this part upon them and putting them under control of the simulation as well.
5) Once a neuron is entirely isolated and can be handled entirely within the simulation, the signal is sent for apoptosis.
6) This pattern continues until the entire brain exists only in the simulation.
And thus you take any living entity and entirely digitize their consciousness, without any single moment defining their transition from the physical world to the digital one, and without "copying" them.
This is a key first step in something I've been thinking about for a long time, and I'm thrilled to see it. I doubt I'll live to see all the steps, or that anyone alive today will. But I'm thrilled to see the first steps taken down this road.
More near-term, one can envision all sorts of incredible properties with an optical communication link set up with cells. For example, imagine that you instrument cells in a cancerous organ with genes that can be instructed individually to force the cell into apoptosis, and which flash on various frequencies corresponding to various cellular activities. You look for cellular activities which correspond to cancerous behavior, and when you see them, you tell that cell to kill itself. You really have something way better than all of that unrealistic "nanomachine medicine" stuff that sci-fi writers have been obsessing over for ages.