I recently read this article about a group of physicists and neurobiologists working on developing advancements to magnetoencephelography, presumably based on new quantum metrology and quantum information techniques based on the publication titles of one of the physicists involved. Near the bottom of that article, the following statement is made:
In the long term, the intention is that the systems will be used to reproduce images of both the entire brain, cerebral circulation, and of the smallest synapses with a resolution at nano-molecular level.
My question is, is this theoretically possible? Optical imaging (superresolution aside) is diffraction limited in its maximum resolution. If we assume a model of the brain as a network (directed graph) with some distribution of weak electrical pulses traveling along the edges, then:
Question: Is it theoretically possible to reconstruct this network in full?
The following issues need to be addressed to fully answer this question:
(1) The electrical flows in axons and dendrites are tiny and so magnetic fields should also be quite small. Ion flows across synapses are even smaller. Would a single synapse or even a single axon produce a large enough magnetic field to be measurable? How much noise could be tolerated?
(2) Many neurons will be firing in rapid succession. Even if a single neuron, axon, or synapse could theoretically be measured in isolation, would it still be measurable if surrounded by other neurons / axons / dendrites / synapses that are also firing?