Америкалық биолог Джеральд Эдельман: Иммунология және нейробиологияның зерттеушісі

American biologist

Gerald Maurice Edelman ('/ɛ//d//əl//m//ən/; July 1, 1929 – May 17, 2014) was an American biologist who shared the 1972 Nobel Prize in Physiology or Medicine for work with Rodney Robert Porter on the immune system. Edelman's Nobel Prize winning research concerned discovery of the structure of antibody molecules. In interviews, he has said that the way the components of the immune system evolve over the life of the individual is analogous to the way the components of the brain evolve in a lifetime. There is a continuity in this way between his work on the immune system, for which he won the Nobel Prize, and his later work in neuroscience and in philosophy of mind.

Gerald Edelman was born in 1929 in Ozone Park, Queens, New York, to Jewish parents, physician Edward Edelman, and Anna (née Freedman) Edelman, who worked in the insurance industry. He studied violin for years, but eventually realized that he did not have the inner drive needed to pursue a career as a concert violinist, and decided to go into medical research instead. He attended public schools in New York, graduating from John Adams High School, and then attended Ursinus College, where he graduated magna cum laude with a B. S. in 1950. He received an M. D. from the University of Pennsylvania School of Medicine in 1954. After his Nobel prize award, Edelman began research into the regulation of primary cellular processes, particularly the control of cell growth and the development of multi celled organisms, focusing on cell to cell interactions in early embryonic development and in the formation and function of the nervous system. These studies led to the discovery of cell adhesion molecules (CAMs), which guide the fundamental processes that help an animal achieve its shape and form, and by which nervous systems are built. One of the most significant discoveries made in this research is that the precursor gene for the neural cell adhesion molecule gave rise in evolution to the entire molecular system of adaptive immunity. For his efforts, Edelman was an elected member of both the American Academy of Arts and Sciences (1968) and the American Philosophical Society (1977).

While in Paris serving in the Army, Edelman read a book that sparked his interest in antibodies. He decided that, since the book said so little about antibodies, he would investigate them further upon returning to the United States, which led him to study physical chemistry for his 1960 Ph. D. For this work, Edelman and Porter shared the Nobel Prize in Physiology or Medicine in 1972.

Edelman's early research on the structure of antibody proteins revealed that disulfide bonds link together the protein subunits. A key feature of these models included the idea that the antigen binding domains of antibodies (Fab) include amino acids from both the light and heavy protein subunits. The inter chain disulfide bonds help bring together the two parts of the antigen binding domain.

Edelman and his colleagues used cyanogen bromide and proteases to fragment the antibody protein subunits into smaller pieces that could be analyzed for determination of their amino acid sequence. At the time when the first complete antibody sequence was determined (1969) it was the largest complete protein sequence that had ever been determined. The availability of amino acid sequences of antibody proteins allowed recognition of the fact that the body can produce many different antibody proteins with similar antibody constant regions and divergent antibody variable regions.

Topobiology is Edelman's theory which asserts that morphogenesis is driven by differential adhesive interactions among heterogeneous cell populations and it explains how a single cell can give rise to a complex multi cellular organism. As proposed by Edelman in 1988, topobiology is the process that sculpts and maintains differentiated tissues and is acquired by the energetically favored segregation of cells through heterologous cellular interactions.

Edelman's theory of neuronal group selection, also known as 'Neural Darwinism', has three basic tenets—Developmental Selection, Experiential Selection and Reentry. Developmental selection the formation of the gross anatomy of the brain is controlled by genetic factors, but in any individual the connectivity between neurons at the synaptic level and their organisation into functional neuronal groups is determined by somatic selection during growth and development. This process generates tremendous variability in the neural circuitry—like the fingerprint or the iris, no two people will have precisely the same synaptic structures in any comparable area of brain tissue. Their high degree of functional plasticity and the extraordinary density of their interconnections enables neuronal groups to self organise into many complex and adaptable "modules." These are made up of many different types of neurons which are typically more closely and densely connected to each other than they are to neurons in other groups. Experiential selection Overlapping the initial growth and development of the brain, and extending throughout an individual's life, a continuous process of synaptic selection occurs within the diverse repertoires of neuronal groups. This process may strengthen or weaken the connections between groups of neurons and it is constrained by value signals that arise from the activity of the ascending systems of the brain, which are continually modified by successful output. Experiential selection generates dynamic systems that can 'map' complex spatio temporal events from the sensory organs, body systems and other neuronal groups in the brain onto other selected neuronal groups. Edelman argues that this dynamic selective process is directly analogous to the processes of selection that act on populations of individuals in species, and he also points out that this functional plasticity is imperative, since not even the vast coding capability of entire human genome is sufficient to explicitly specify the astronomically complex synaptic structures of the developing brain. Reentry —the concept of reentrant signalling between neuronal groups. He defines reentry as the ongoing recursive dynamic interchange of signals that occurs in parallel between brain maps, and which continuously interrelates these maps to each other in time and space (film clip: Edelman demonstrates spontaneous group formation among neurons with re entrant connections). Reentry depends for its operations on the intricate networks of massively parallel reciprocal connections within and between neuronal groups, which arise through the processes of developmental and experiential selection outlined above. Edelman describes reentry as "a form of ongoing higher order selection that appears to be unique to animal brains" and that "there is no other object in the known universe so completely distinguished by reentrant circuitry as the human brain."

Edelman and Gally were the first to point out the pervasiveness of degeneracy in biological systems and the fundamental role that degeneracy plays in facilitating evolution.

Edelman founded and directed The Neurosciences Institute, a nonprofit research center in San Diego that between 1993 and 2012 studied the biological bases of higher brain function in humans. He served on the scientific board of the World Knowledge Dialogue project. Edelman was a member of the USA Science and Engineering Festival's advisory board.

Edelman married Maxine M. Morrison in 1950. recording artist, and writer. Some observers have noted that a character in Richard Powers' The Echo Maker may be a nod at Edelman.

Later in his life, he had prostate cancer and Parkinson's disease. Edelman died on May 17, 2014, in La Jolla, California, aged 84.