What did MICrONS add to a wiring diagram? · Grey Matter

It recorded what the neurons did before mapping how they were wired.

What did MICrONS add to a wiring diagram?

It recorded what the neurons did before mapping how they were wired. While a mouse watched films, calcium imaging followed the responses of about 75,000 neurons in a cubic millimetre of visual cortex; the same cube was then cut and imaged by electron microscopy, and 523 million synapses were traced among its 200,000 cells. Because each reconstructed neuron could be matched to its recorded responses, the map could be asked who connects to whom by function. One answer was a like-to-like rule: excitatory neurons that respond to similar features are more likely to be connected, within and across layers and areas.