In 1991 Neher and Sakmann were awarded the 1991 Nobel Prize in Physiology or Medicine for "their discoveries concerning the function of single ion channels in cells." They were also awarded the prize for the invention of the patch clamp technique, a laboratory technique in electrophysiology that allows the study of single or multiple ion channels in cells, improving understanding of the involvement of channels in fundamental cell processes such as action potentials and nerve activity. The technique allowed investigation of the behavior of single protein molecules.