Detecting Neuron Signals

Is it possible to accurately detect the electrical signal being emitted by a single neuron or a very small group of neurons inside the nervous system in a non-invasive way? Maybe using a collection of magnets with their magnetic field manipulated in a very small tip focused on the neuron in question or perhaps by means of some sort of MRI which could create a flat image of all the signals being fired at 'that' particular place at 'this' exact moment? (I don't know if an MRI is even capable of making such an image but, an MRI uses magnetism to make detections and an electron is capable of being influenced by magnets so perhaps it's possible?)
- Skip (age 18)
Netherlands

The trick is "non-invasive" since small electrodes inserted in the neuron can sense the voltage. Other methods don't give a direct voltage reading but can be used to tell when a neuron is firing. I don't believe that MRI has good enough resolution for what you want. (See, e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4520483/. )There are fluorescent dies that can be used to sense activity at the single-neuron level, but I'm not sure how you'd visualize the result when it's inside a working brain.

Mike W. 

(published on 06/09/2017)