| Citation | Bert Sakmann has, in collaboration with Professor Erwin Neher, opened up a wide new field in cellular and membrane biology. In 1991, Neher and Sakmann received a Nobel Proze for their invention and experimental application of the so-called "patch-clamp" technique. This technique, which enables one to make visible, and record directly, the opening and closure of single ion channels in cell membranes, has made a tremendous impact and is now being used in many leading laboratories internationally. It improved the resolution of measurement of ionic membrane currents by several orders of magnitude and so made it possible to demonstrte the existence and explore the functional properties of elementary membrane channels in living cells. Neher and Sakmann developed and used this method in 1976 to record the minute elementry current pulses flowing through the skeletal muscle membrane when it is activated by the neuromuscular transmitter acetylcholine and its analogues. This work was the beginning of a new development in the study of cell membranes, and gradually with the help of further technical refinements and personal advice by its originators, was taken up in a very large number of laboratories all over the world. It had an enormous influence far exceeding the field of neurphysiology for which it had originally been designed. This is well illustrated by a quotation from a review of recent advances in renal physiology (Palmer, L.G., Patch-clamp technique in renal Physiology. American Journal of Physiology 250: F379-385, 1986) "the patch-clamp technique [of Neher and Sakmann] has revolutionised electrophysiology. With it, a new level of detail in the study of many ion channels, as well as the existence of many new types of channels, have been revealed. In a more general sense, the patch-clamp approach allows the function of a single protein molecule to be oberved while the molecule is in its native environment in the cell, a feat that to my knowledge is unprecedented in biology". Bert Sakmann is continuing to be an outstanding leader in this field. More recently he combined his electrophysiological approach with biochemical methods to study the modifications of ion channels which are brought about by site-directed mutations of the receptor molecule. He has also demonstrated the special usefulness of the patch-clamp in exploring neuronal structures in the central nervous system which are too small to be examined by previously available recording techniques. This in itself opens up important new avenues in the exploration of the brain. For example, it has become possible to investigate central synaptic transmission with a resolution previously attainable only in the peripheral nervous system. We should also mention that Professor Sakmann has been most helpful and generous with his time in teaching and advising the many colleagues who visit his laboratory to learn the technical tricks of his method. |