Ichiji Tasaki

Dr. Ichiji Tasaki (田崎一二)(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.[1] [2] 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.[3][4] His description of this process, termed saltatory conduction, is prominent in every biology textbook[5] .

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.[6] This effort led to the development of the field of audiology, indirectly providing the basis for diagnosing and treating many hearing disorders.

Research interests

Tasaki began his career at the National Institutes of Health 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.[7][8][9]

References

  1. ^ "Ichiji Tasaki Neurophysiologist". Washington Post. January 20, 2009. http://www.washingtonpost.com/wp-dyn/content/article/2009/01/19/AR2009011903152.html. Retrieved 15 August 2011. 
  2. ^ van Hollen, Chris (11). "Tribute to Dr. Ichiji Tasaki". United States House of Representatives. http://vanhollen.house.gov/News/DocumentSingle.aspx?DocumentID=136592. Retrieved 15 August 2011. 
  3. ^ Tasaki, I. The electro-saltatory transmission of the nerve impulse and the effect of narcosis upon the nerve fiber. Am J Physiol 127: 211-227, 1939.
  4. ^ Tasaki, I. and Takeuchi, T. Der am Ranvierschen Knoten entstehende Aktionsstrom und seine Bedeutung für die Erregungsleitung. Pflügers Arch ges Physiol. 244: 696-711, 1941.
  5. ^ "Biophysicist Tasaki Leaves Extraordinary Scientific Legacy". National Institute of Health. http://nihrecord.od.nih.gov/newsletters/2009/02_20_2009/milestones.htm. Retrieved 15 August 2011. 
  6. ^ Tasaki, I (1954). "Nerve impulses in individual auditory nerve fibers of guinea pig". Journal of neurophysiology 17 (2): 97–122. PMID 13143414. 
  7. ^ Tasaki, I (1999). "Rapid structural changes in nerve fibers and cells associated with their excitation processes". The Japanese journal of physiology 49 (2): 125–38. doi:10.2170/jjphysiol.49.125. PMID 10393347. 
  8. ^ Tasaki, I; Matsumoto, G (2002). "On the cable theory of nerve conduction". Bulletin of mathematical biology 64 (6): 1069–82. doi:10.1006/bulm.2002.0310. PMID 12508531. 
  9. ^ Tasaki, I (2004). "On the conduction velocity of nonmyelinated nerve fibers". Journal of integrative neuroscience 3 (2): 115–24. doi:10.1142/S0219635204000415. PMID 15285049. 

 This article incorporates public domain material from websites or documents of the National Institute of Mental Health.

Further reading

Principal Investigator Ichiji Tasaki at the National Institutes of Health

Biophysicist Tasaki Leaves Extraordinary Scientific Legacy