I've been hunting for the answer to this question on Google Scholar for the past half hour and thought I would ask some actual human beings.
What is the most promising brain imaging technology for being able to see connections at the neuron level in the brain? Does anything allow us to currently see neurons ennervating other neurons (non-invasively, i.e. in a live human brain), and if not, what are your predictions for this technology in the next 5-10 years?