Gerald Edelman | |
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| Born | Gerald Maurice Edelman (1929-07-01)July 1, 1929 New York City, U.S. |
| Died | May 17, 2014(2014-05-17) (aged 84) La Jolla, California, U.S. |
| Education | Ursinus College (BS) University of Pennsylvania (MD) Rockefeller University (PhD) |
| Spouse | |
| Awards | Nobel Prize in Physiology or Medicine (1972) |
| Scientific career | |
| Fields | Immunology Neuroscience Philosophy of mind |
| Doctoral students | Paul David Gottlieb,Olaf Sporns |
Gerald Maurice Edelman (/ˈɛdəlmən/; July 1, 1929 – May 17, 2014) was an Americanbiologist who shared the 1972Nobel Prize in Physiology or Medicine for work withRodney Robert Porter on theimmune system.[1] Edelman's Nobel Prize-winning research concerned discovery of the structure ofantibody molecules.[2] 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 theNobel Prize, and his later work inneuroscience and inphilosophy of mind.
Gerald Edelman was born in 1929[3] inOzone Park, Queens, New York, toJewish parents,physician Edward Edelman, and Anna (née Freedman) Edelman, who worked in the insurance industry.[4] 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.[5] He attended public schools in New York, graduating fromJohn Adams High School,[6] and then attendedUrsinus College, where he graduatedmagna cum laude with aB.S. in 1950. He received anM.D. from theUniversity of Pennsylvania School of Medicine in 1954.[4]
After a year at the Johnson Foundation for Medical Physics, Edelman became aresident at theMassachusetts General Hospital; he then practiced medicine in France while serving withUS Army Medical Corps.[4] In 1957, Edelman joined theRockefeller Institute for Medical Research as a graduate fellow, working in the laboratory of Henry Kunkel and receiving aPh.D. in 1960.[4] The institute made him the assistant (later associate) dean of graduate studies; he became a professor at the school in 1966.[4] In 1992, he moved toCalifornia and became a professor ofneurobiology atThe Scripps Research Institute.[7]
After his Nobel prize award, Edelman began research into the regulation of primarycellular processes, particularly the control of cell growth and the development ofmulti-celled organisms, focusing on cell-to-cell interactions in earlyembryonic development and in the formation and function of the nervous system. These studies led to the discovery ofcell 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 precursorgene for the neural cell adhesion molecule gave rise in evolution to the entire molecular system ofadaptive immunity.[8]
For his efforts, Edelman was an elected member of both theAmerican Academy of Arts and Sciences (1968) and theAmerican Philosophical Society (1977).[9][10]
While in Paris serving in the Army, Edelman read a book that sparked his interest inantibodies.[11] 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 studyphysical chemistry for his 1960 Ph.D.[11] Research by Edelman and his colleagues andRodney Robert Porter in the early 1960s produced fundamental breakthroughs in the understanding of the antibody's chemical structure, opening a door for further study.[12] For this work, Edelman and Porter shared theNobel Prize in Physiology or Medicine in 1972.[1]
In its Nobel Prize press release in 1972, theKarolinska Institutet lauded Edelman and Porter's work as a major breakthrough:
The impact of Edelman's and Porter's discoveries is explained by the fact that they provided a clear picture of the structure and mode of action of a group of biologically particularly important substances. By this they laid a firm foundation for truly rational research, something that was previously largely lacking in immunology. Their discoveries represent clearly a break-through that immediately incited a fervent research activity the whole world over, in all fields of immunological science, yielding results of practical value for clinical diagnostics and therapy.[13]
Edelman's early research on the structure of antibody proteins revealed thatdisulfide bonds link together the protein subunits.[2] The protein subunits of antibodies are of two types, the larger heavy chains and the smaller light chains. Two light and two heavy chains are linked together by disulfide bonds to form a functional antibody.
Using experimental data from his own research and the work of others, Edelman developed molecular models of antibody proteins.[14] A key feature of these models included the idea that theantigen binding domains of antibodies (Fab) includeamino acids from both thelight andheavy protein subunits. The inter-chain disulfide bonds help bring together the two parts of the antigen binding domain.
Edelman and his colleagues usedcyanogen bromide andproteases to fragment the antibody protein subunits into smaller pieces that could be analyzed for determination of theiramino acid sequence.[15][16] At the time when the first complete antibody sequence was determined (1969)[17] 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 antibodyvariable 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.
In his later career, Edelman was noted for his theory ofconsciousness, documented in a trilogy of technical books and in several subsequent books written for a general audience, includingBright Air, Brilliant Fire (1992),[18][19]A Universe of Consciousness (2001, withGiulio Tononi),Wider than the Sky (2004) andSecond Nature: Brain Science and Human Knowledge (2007).
InSecond Nature Edelman defines human consciousness as:
The first of Edelman's technical books,The Mindful Brain (1978),[20] develops his theory ofNeural Darwinism, which is built around the idea of plasticity in the neural network in response to the environment. The second book,Topobiology (1988),[21] proposes a theory of how the original neuronal network of a newborn'sbrain is established during development of theembryo.The Remembered Present (1990)[22] contains an extended exposition of his theory ofconsciousness.
In his books, Edelman proposed a biological theory of consciousness, based on his studies of the immune system. He explicitly roots his theory withinCharles Darwin's Theory ofNatural Selection, citing the key tenets of Darwin's population theory, which postulates that individual variation within species provides the basis for the natural selection that eventually leads to the evolution of new species.[23] He explicitly rejecteddualism and also dismissed newer hypotheses such as the so-called'computational' model of consciousness, which liken the brain's functions to the operations of a computer. Edelman argued that mind and consciousness are purely biological phenomena, arising from complex cellular processes within the brain, and that the development of consciousness and intelligence can be explained by Darwinian theory.
Edelman's theory seeks to explain consciousness in terms of the morphology of the brain. A brain comprises a massive population of neurons (approx. 100billion cells) each with an enormous number of synaptic connections to other neurons. During development, the subset of connections that survive the initial phases of growth and development will make approximately 100trillion connections with each other. A sample of brain tissue the size of a match head contains about a billion connections, and if we consider how these neuronal connections might be variously combined, the number of possible permutations becomes hyper-astronomical – in the order of ten followed by millions of zeros.[24] The young brain contains many more neural connections than will ultimately survive to maturity, and Edelman argued that this redundant capacity is needed because neurons are the only cells in the body that cannot be renewed and because only those networks best adapted to their ultimate purpose will be selected as they organize into neuronal groups.
Edelman's theory of neuronal group selection, also known as 'Neural Darwinism', has three basic tenets—Developmental Selection, Experiential Selection and Reentry.
Edelman and Gally were the first to point out the pervasiveness ofdegeneracy in biological systems and the fundamental role that degeneracy plays in facilitating evolution.[27]
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Edelman founded and directedThe Neurosciences Institute, a nonprofit research center inSan 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.[28]
Edelman was a member of theUSA Science and Engineering Festival's advisory board.[29]
Edelman married Maxine M. Morrison in 1950.[4] They have two sons, Eric, a visual artist in New York City, and David, an adjunct professor of neuroscience atUniversity of San Diego. Their daughter, Judith Edelman, is abluegrass musician,[30] recording artist, and writer. Some observers[who?] have noted that a character inRichard Powers'The Echo Maker may be a nod to Edelman.
Later in his life, he hadprostate cancer andParkinson's disease.[31] Edelman died on May 17, 2014, inLa Jolla, California, aged 84.[3][32][33]
, accessed 11 October 2020Their discoveries represent clearly a break-through that immediately incited a fervent research activity the whole world over ...
