"demonstrated that an injury current, the "demarcation current," flowed between the cut and intact surface of a muscle or nerve, that this current momentarily disappeared when the muscle contracted, and that a cut nerve could be excited when an underlying muscle twitched (the "induced twitch phenomenon"). Du Bois-Reymond recognized that Matteucci's findings could be explained by an action current, the "negative Schwankung," which was an oscillation of the demarcation current and which reflects the excitation of the nerve fibers. It was the first intimation of the nerve impulse and it was from this observation of du Bois-Reymond that the all subsquent work on the nerve impulse evolved. The understanding of the nerve impulse would become the most important task—a holy grail, as it were—for later neuroscientists."