Susumu Tonegawa

Susumu Tonegawa (利根川 進 Tonegawa Susumu, September 6, 1939) is a Japanese scientist who won the 1987 Nobel Prize in Physiology or Medicine for the discovery of the genetic mechanism that produces antibody diversity. Although he won the Nobel Prize for his work in immunology, Tonegawa is a molecular biologist by profession and again switched fields after his Nobel Prize; he now studies neuroscience, examining the molecular, cellular, and neural basis of memory formation and retrieval.

Early years and education

Tonegawa was born in Nagoya, Japan and attended Hibiya High School in Tokyo. While a student at Kyoto University, Tonegawa became fascinated with operon theory after reading papers scientists François Jacob and Jacques Monod, to whom he credits part of the credit for inspiring his interest in molecular biology. Tonegawa graduated from Kyoto University in 1963. Because the options for studying molecular biology in Japan were limited in At that time, he moved to the University of California, San Diego to pursue graduate studies under the supervision of Dr. Masaki Hayashi. He earned his doctoral degree in 1968.

Career

Tonegawa did postdoctoral work at the Salk Institute in San Diego in the lab of Renato Dulbecco. With the encouragement of Dr. Dulbecco, Tonegawa moved to the Basel Institute for Immunology, in Basel, Switzerland in 1971, where he applied his knowledge of molecular biology in the field of immunology and carried out his notable studies.

In 1981, Tonegawa became a professor at the Massachusetts Institute of Technology. In 1994, he was appointed director of the MIT Center for Learning and Memory, which became, under his guidance, the Picower Center for Learning and Memory. He resigned from his directorship in 2006 and currently serves as the Picower Professor of Neurosciences and Biology and as an Investigator at the Howard Hughes Medical Institute.

Tonegawa has also been director of the RIKEN Institute for Brain Sciences since 2009.

Research

Discovering immunological diversity

Discovered that certain elements of the genetic mass (DNA) could be transferred and regrouped in the course of development when passing from the embryonic cell to the state of the B lymphocyte. He demonstrated that each lymphocyte is capable of forming the necessary antibody, that is, the antibody that the body needs at all times. Faced with an attack by a certain antigen, a cellular response of the organism is produced and produces the appropriate recombination of genes to form the specific antibody against that antigen. Given these findings, Tonegawa came to formulate the theory that the quantity and quality of the immune response is genetically conditioned.

Thanks to his work, it has been possible to find out how many immunoglobulin genes humans have, and how they give rise to a multitude of specific antibodies.

He was awarded the Nobel Prize in Physiology or Medicine in 1987.

Neuroscience

In 1990, Tonegawa changed his field of research from immunology to neuroscience. His laboratory pioneered the use of transgenic and gene knockout technologies in mammalian systems. He discovered an enzyme that he named CaMKII (in 1992), as well as the NMDA synaptic receptor (in 1996), both of which play crucial roles in memory formation.

Tonegawa's lab found that neural dendritic spines in the temporal lobe are a likely target for treatment of fragile X syndrome. With one dose of the inhibitory drug FRAX586, Tonegawa showed a marked reduction in fragile X syndrome symptoms in a mouse model.

Tonegawa was among the first researchers to use optogenetics and biotechnology in neuroscience, which has resulted in pioneering work in the identification and manipulation of memory cell engrams.

His lab continues to employ the technology of optogenetics and virus injection techniques to further his discoveries of engram cell assembly. Notably, Tonegawa has discovered the role of engram memory cell assemblies in memory valence, as well as their role in brain disorders such as depression, amnesia, and Alzheimer's disease. These works are proofs of concept for future medical treatments in humans through the manipulation of engram memory assemblies.

Personal life

Tonegawa currently lives in Boston with his wife, Mayumi Tonegawa, who worked as a director/interviewer at NHK (Japan Broadcasting Corporation) and is now a freelance science writer. The couple have three children.

Tonegawa is a fan of the Boston Red Sox and threw a starting pitch during the 2004 World Series championship season.