So you want to image every neuron in the brain of a vertebrate? What kind of crazy man are you? Misha B. Ahrens, that’s who.
In what can only be described as a “crazy awesome” experiment, Ahrens used a technique that’s been recently emerging called light sheet microscopy to image the activity of (nearly) every neuron in the zebrafish brain simultaneously. The whole method faces a slight problem in that neurons are active on the order of milliseconds whereas Ahrens can only image the whole brain every 1.3 seconds. Still, it seems reasonable that most behaviorally relevant activity can be captured at that speed. A larger problem is that they might be activating neural activity by shining light at the zebrafish’s eyes.
This is only a methods paper which I’m guessing means that they’re presenting a ‘weak’ result, with a super awesome result to come in 6-12 months in Nature. Their weak result still showcases the power of their method: by looking at single unit activity, they are able to find previously unknown coupling across different regions as well as specific subpopulations that are linked in distinct ways.
Awesome things are coming from the Ahrens lab. I foresee it.
Ahrens, M., & Keller, P. (2013). Whole-brain functional imaging at cellular resolution using light-sheet microscopy Nature Methods DOI: 10.1038/nmeth.2434