text: While the idea of non-synaptic interactions between neurons has existed since the 19th century, there has historically been considerable skepticism in the field of neuroscience. Many people believed that the micro electrical fields produced by the neurons themselves were so small that they were negligible. While many supporters of the ephaptic coupling theory have been trying to prove its existence through experiments that block both chemical and electrical synapses, still some opponents in the field express caution. For example, in 2014, one scientist published a review that presents his skepticism on the idea of ephaptic coupling, saying “The agreement between their simulations and Poelzing’s data is impressive, but I will need a more definitive experimental confirmation before I can embrace the ephaptic hypothesis.”  He bases his caution in wanting more distinction between gap junctions' propagation of charge and true ephaptic coupling. Whether it is a true lack of evidence or simply obstinance in the face of change, many in the field are still not entirely convinced there is unambiguous evidence of ephaptic coupling. 
  Research continues and in 2018 what appears to be a definitive experiment was published. A process of slow wave propagation in the brain of about 0.1m per second has been shown in vivo. Slow wave propagation was also recorded by inserting two electrodes into two ends of a piece of mouse brain taken from a freshly killed mouse. The tissue was then cut between the two electrode positions, severing any possible link by neurons or gap junctions between the two electrodes. The slow wave continued to propagate and could only be stopped by separating the two pieces of tissue with a 400-micron gap. Assuming the reproducibility of this experiment skeptics of ephaptic coupling should be satisfied it is a real phenomenon and investigations will focus now on its mechanisms and role rather than its existence.