Sunday, June 3, 2007



1991 Nobel Laureate in Physiology or Medicine "for their discoveries concerning the function of single ion channels in cells"

Born: 1942
Residence: Germany
Affiliation: Max-Planck-Institut für Medizinische Forschung, Heidelberg

He shared the Nobel Prize in Physiology or Medicine with Erwin Neher in 1991 for their work on "the function of single ion channels in cells," and invention of the patch clamp.

Born in Stuttgart, Sakmann enroled in Volksschule in Lindau, and completed the Wagenburg gymnasium in Stuttgart in 1961. He studied medicine from 1967 onwards in Tübingen, Freiburg, Berlin, Paris and Munich. After completing his medical exams at Ludwig-Maximilians University in Munich, he became a medical assistant in 1968 at Munich University, while also working as a scientific assistant (Wissenschaftlicher Assistant) at Munich's Max-Planck-Institut für Psychiatrie, in the Neurophysiology Department under Otto Detlev Creutzfeldt. In 1971 he moved to University College in London, where he worked in the Department of Biophysics under Bernard Katz. In 1974 he completed his medical dissertation, under the title Elektrophysiologie der neuralen Helladaptation in der Katzenretina (Electrophysiology of Neural Light Adaption in the Cat Retina) in the Medical Faculty of Göttingen University.Afterwards (still in 1974), Sakmann returned to the lab of Otto Creutzfeldt, who had meanwhile moved to the Max Planck Institute for Biophysical Chemistry in Göttingen. Sakmann joined the membrane biology group the in 1979.

To mention in brief about his work, it can be described as, the first recordings of native ion channels in biological membranes were made by Bert Sakmann and Erwin Neher using an innovative modification of the voltage-clamp method. Rather than penetrating the cell with a sharp electrode as was traditionally done in voltage-clamp experiments, Neher and Sakmann fabricated blunt-tipped glass pipettes that, when pressed gently against the membrane of a cell would isolate a small area of membrane (diameter = 1 mm). In this way they were able to trap or isolate one or a few ion channels in the membrane. Typically, a single ion channel conducts about 10 million ions per second. The corresponding current, however, is not as impressive; only a few picoamperes. The primary difficulty for Sakmann and Neher in their development of the patch clamp method was noise. Transistors used to make the amplifier, and thermal noise associated with a low resistance seal between the glass pipette and the membrane often obscured the rectangular-shaped currents arising from opening of single channels. In the years following the introduction of their method, two improvements were made to compensate for these problems. New low-noise transistors were used in the construction of high quality amplifiers (Fred Sigworth made significant contributions here). Also, in 1981 the "gigaseal" modification of the method was introduced by Owen Hamill in Sakmann's group. Seals exceeding 10 GW were subsequently reported, and impressive low-noise recordings could be made without difficulty.

Compiled by: minhaz []

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