Ichiji Tasaki
Encyclopedia
Dr. Ichiji Tasaki(October 10, 1910 - January 4, 2009) was a Japanese biophysicist and physician involved in research relating to the electical impulses in the nervous system. He is credited with discovering the insulating function of the myelin sheath. His discoveries provided the foundation for a better understanding of diseases such as multiple sclerosis
, in which myelin is lost or damaged.
Tasaki was born in Japan in 1910 where he attended medical school at the urging of his mother and received his M.D. in 1938. However, instead of practicing medicine, he decided to pursue his first love: biophysics. While in Japan, he studied vertebrate nerve fibers and discovered the insulating function of the myelin sheath, a material that speeds the conduction of nerve impulses. He also was the first to show that electrical impulses traveling along myelinated nerve cells actually "jump" between the breaks in the myelin wrapping, called nodes of Ranvier. His description of this process, termed saltatory conduction
, is prominent in every biology textbook .
After World War II
, Tasaki's research took him to England
and to Switzerland
, where he further studied the properties of nerve fibers. In 1951, he came to the United States to work at Washington University in St. Louis
. While there, Tasaki and his colleagues demonstrated how vibrations that occur in the cochlea
in response to sound are translated into electrical signals that the brain can interpret. This effort led to the development of the field of audiology
, indirectly providing the basis for diagnosing and treating many hearing disorders.
in 1953, at NINDS, then called the National Institute of Neurological Disorders and Blindness. Later, when NIMH
separated from that institute, he moved with the new institute, where he was a lab chief for 22 years. At the time of his death, he was on detail to NICHD. Since coming to NIH, Tasaki studied the physical and chemical processes that occur in nerve membranes.
Biophysicist Tasaki Leaves Extraordinary Scientific Legacy
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
, in which myelin is lost or damaged.
Tasaki was born in Japan in 1910 where he attended medical school at the urging of his mother and received his M.D. in 1938. However, instead of practicing medicine, he decided to pursue his first love: biophysics. While in Japan, he studied vertebrate nerve fibers and discovered the insulating function of the myelin sheath, a material that speeds the conduction of nerve impulses. He also was the first to show that electrical impulses traveling along myelinated nerve cells actually "jump" between the breaks in the myelin wrapping, called nodes of Ranvier. His description of this process, termed saltatory conduction
Saltatory conduction
Saltatory conduction is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials without needing to increase the diameter of an axon.-Mechanism:Because the cytoplasm of the axon is electrically...
, is prominent in every biology textbook .
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, Tasaki's research took him to England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
and to Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, where he further studied the properties of nerve fibers. In 1951, he came to the United States to work at Washington University in St. Louis
Washington University in St. Louis
Washington University in St. Louis is a private research university located in suburban St. Louis, Missouri. Founded in 1853, and named for George Washington, the university has students and faculty from all fifty U.S. states and more than 110 nations...
. While there, Tasaki and his colleagues demonstrated how vibrations that occur in the cochlea
Cochlea
The cochlea is the auditory portion of the inner ear. It is a spiral-shaped cavity in the bony labyrinth, making 2.5 turns around its axis, the modiolus....
in response to sound are translated into electrical signals that the brain can interpret. This effort led to the development of the field of audiology
Audiology
Audiology is the branch of science that studies hearing, balance, and related disorders. Its practitioners, who treat those with hearing loss and proactively prevent related damage are audiologists. Employing various testing strategies Audiology (from Latin , "to hear"; and from Greek , -logia) is...
, indirectly providing the basis for diagnosing and treating many hearing disorders.
Research interests
Tasaki began his career at the National Institutes of HealthNational Institutes of Health
The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...
in 1953, at NINDS, then called the National Institute of Neurological Disorders and Blindness. Later, when NIMH
National Institute of Mental Health
The National Institute of Mental Health is one of 27 institutes and centers that make up the National Institutes of Health...
separated from that institute, he moved with the new institute, where he was a lab chief for 22 years. At the time of his death, he was on detail to NICHD. Since coming to NIH, Tasaki studied the physical and chemical processes that occur in nerve membranes.
Further reading
Principal Investigator Ichiji Tasaki at the National Institutes of HealthBiophysicist Tasaki Leaves Extraordinary Scientific Legacy