Short answer is no one knows, but there's tantalising evidence that it has to do with macro extracellular electric gradient in tissue: https://www.youtube.com/w

Short answer is no one knows, but there's tantalising evidence that it has to do with macro extracellular electric gradient in tissue: https://www.youtube.com/watch?v=RjD1aLm4Thg https://www.youtube.com/watch?v=RjD1aLm4Thg