Sir Bernard Katz
|Died||20 April 2003 92) (aged|
|Alma mater||University of Leipzig|
|Known for||Neurophysiology of the synapse in 197|
|Spouse(s)||Marguerite ("Rita") Penly Katz (d.1999) (2 children)|
|Institutions|| University College London |
University of Sydney
|Academic advisors||Archibald Hill|
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Sir Bernard Katz, FRS(26 March 1911 – 20 April 2003) was a German-born Australian physician and biophysicist, noted for his work on nerve physiology. He shared the Nobel Prize in physiology or medicine in 1970 with Julius Axelrod and Ulf von Euler. He was made a Knight Bachelor in 1969.
Katz was born in Leipzig, Germany, to a family originally from Russia, the son of Eugenie (Rabinowitz) and Max Katz, a fur merchant.He was educated at the Albert Gymnasium in that city from 1921 to 1929 and went on to study medicine at the University of Leipzig. He graduated in 1934 and fled to Britain in February 1935
Katz went to work at University College London, initially under the tutelage of Archibald Vivian Hill. He finished his PhD in 1938 and won a Carnegie Fellowship to study with John Carew Eccles at the Kanematsu Institute of Sydney Medical School.During this time, both he and Eccles gave research lectures at the University of Sydney. He was naturalised in 1941 and joined the Royal Australian Air Force in 1942. He spent the war in the Pacific as a radar officer and returned to UCL as an assistant director in 1946.
Back in England he also worked with the 1963 Nobel prize winners Alan Hodgkin and Andrew Huxley. Katz was made a professor at UCL in 1952 and head of biophysics, he was elected a Fellow of the Royal Society (FRS) in 1952.He stayed as head of biophysics until 1978 when he became emeritus professor.
Katz married Marguerite Penly in 1945. He died in London on 20 April 2003, at the age of 92. He is survived by his two sons, David and Jonathan.David is a practising doctor, while Jonathan is Public Orator of The University of Oxford.
His research uncovered fundamental properties of synapses, the junctions across which nerve cells signal to each other and to other types of cells. By the 1950s, he was studying the biochemistry and action of acetylcholine, a signalling molecule found in synapses linking motor neurons to muscles,used to stimulate contraction. Katz won the Nobel for his discovery with Paul Fatt that neurotransmitter release at synapses is "quantal", meaning that at any particular synapse, the amount of neurotransmitter released is never less than a certain amount, and if more is always an integral number times this amount. Scientists now understand that this circumstance arises because, prior to their release into the synaptic gap, transmitter molecules reside in like-sized subcellular packages known as synaptic vesicles, released in a similar way to any other vesicle during exocytosis.
Katz's work had immediate influence on the study of organophosphates and organochlorines, the basis of new post-war study for nerve agents and pesticides, as he determined that the complex enzyme cycle was easily disrupted.
Sir John Carew Eccles was an Australian neurophysiologist and philosopher who won the 1963 Nobel Prize in Physiology or Medicine for his work on the synapse. He shared the prize with Andrew Huxley and Alan Lloyd Hodgkin.
Neurotransmitters are endogenous chemicals that enable neurotransmission. It is a type of chemical messenger which transmits signals across a chemical synapse, such as a neuromuscular junction, from one neuron to another "target" neuron, muscle cell, or gland cell. Neurotransmitters are released from synaptic vesicles in synapses into the synaptic cleft, where they are received by neurotransmitter receptors on the target cells. Many neurotransmitters are synthesized from simple and plentiful precursors such as amino acids, which are readily available from the diet and only require a small number of biosynthetic steps for conversion. Neurotransmitters play a major role in shaping everyday life and functions. Their exact numbers are unknown, but more than 200 unique chemical messengers have been identified.
Chemical synapses are biological junctions through which neurons' signals can be sent to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system to connect to and control other systems of the body.
Sir Henry Hallett Dale was an English pharmacologist and physiologist. For his study of acetylcholine as agent in the chemical transmission of nerve impulses (neurotransmission) he shared the 1936 Nobel Prize in Physiology or Medicine with Otto Loewi.
In neuroscience, an excitatory postsynaptic potential (EPSP) is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential. This temporary depolarization of postsynaptic membrane potential, caused by the flow of positively charged ions into the postsynaptic cell, is a result of opening ligand-gated ion channels. These are the opposite of inhibitory postsynaptic potentials (IPSPs), which usually result from the flow of negative ions into the cell or positive ions out of the cell. EPSPs can also result from a decrease in outgoing positive charges, while IPSPs are sometimes caused by an increase in positive charge outflow. The flow of ions that causes an EPSP is an excitatory postsynaptic current (EPSC).
A neuroscientist is a scientist who has specialised knowledge in the field of neuroscience, the branch of biology that deals with the physiology, biochemistry, anatomy and molecular biology of neurons and neural circuits and especially their association with behaviour and learning.
Ulf Svante von Euler was a Swedish physiologist and pharmacologist. He shared the Nobel Prize in Physiology or Medicine in 1970 for his work on neurotransmitters.
In a neuron, synaptic vesicles store various neurotransmitters that are released at the synapse. The release is regulated by a voltage-dependent calcium channel. Vesicles are essential for propagating nerve impulses between neurons and are constantly recreated by the cell. The area in the axon that holds groups of vesicles is an axon terminal or "terminal bouton". Up to 130 vesicles can be released per bouton over a ten-minute period of stimulation at 0.2 Hz. In the visual cortex of the human brain, synaptic vesicles have an average diameter of 39.5 nanometers (nm) with a standard deviation of 5.1 nm.
End plate potentials (EPPs) are the voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction. They are called "end plates" because the postsynaptic terminals of muscle fibers have a large, saucer-like appearance. When an action potential reaches the axon terminal of a motor neuron, vesicles carrying neurotransmitters are exocytosed and the contents are released into the neuromuscular junction. These neurotransmitters bind to receptors on the postsynaptic membrane and lead to its depolarization. In the absence of an action potential, acetylcholine vesicles spontaneously leak into the neuromuscular junction and cause very small depolarizations in the postsynaptic membrane. This small response (~0.4mV) is called a miniature end plate potential (MEPP) and is generated by one acetylcholine-containing vesicle. It represents the smallest possible depolarization which can be induced in a muscle.
James Edward Rothman is an American biochemist. He is the Fergus F. Wallace Professor of Biomedical Sciences at Yale University, the Chairman of the Department of Cell Biology at Yale School of Medicine, and the Director of the Nanobiology Institute at the Yale West Campus. Rothman also concurrently serves as adjunct professor of physiology and cellular biophysics at Columbia University and a research professor at the UCL Queen Square Institute of Neurology, University College London. Rothman was awarded the 2013 Nobel Prize in Physiology or Medicine, for his work on vesicle trafficking. He received many other honors including the King Faisal International Prize in 1996, the Louisa Gross Horwitz Prize from Columbia University and the Albert Lasker Award for Basic Medical Research both in 2002.
In neuroscience, Dale's principle is a rule attributed to the English neuroscientist Henry Hallett Dale. The principle basically states that a neuron performs the same chemical action at all of its synaptic connections to other cells, regardless of the identity of the target cell. However, there has been disagreement about the precise wording.
Neurotransmission is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron, and bind to and react with the receptors on the dendrites of another neuron a short distance away. A similar process occurs in retrograde neurotransmission, where the dendrites of the postsynaptic neuron release retrograde neurotransmitters that signal through receptors that are located on the axon terminal of the presynaptic neuron, mainly at GABAergic and glutamatergic synapses.
In the nervous system, a synapse is a structure that permits a neuron to pass an electrical or chemical signal to another neuron or to the target effector cell.
Summation, which includes both spatial and temporal summation, is the process that determines whether or not an action potential will be generated by the combined effects of excitatory and inhibitory signals, both from multiple simultaneous inputs, and from repeated inputs. Depending on the sum total of many individual inputs, summation may or may not reach the threshold voltage to trigger an action potential.
Axon terminals are distal terminations of the telodendria (branches) of an axon. An axon, also called a nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses called action potentials away from the neuron's cell body, or soma, in order to transmit those impulses to other neurons, muscle cells or glands.
Cellular neuroscience is a branch of neuroscience concerned with the study of neurons at a cellular level. This includes morphology and physiological properties of single neurons. Several techniques such as intracellular recording, patch-clamp, and voltage-clamp technique, pharmacology, confocal imaging, molecular biology, two photon laser scanning microscopy and Ca2+ imaging have been used to study activity at the cellular level. Cellular neuroscience examines the various types of neurons, the functions of different neurons, the influence of neurons upon each other, and how neurons work together.
Thomas Christian Südhof, ForMemRS, is a German-American biochemist known for his study of synaptic transmission. Currently, he is a professor in the School of Medicine in the Department of Molecular and Cellular Physiology, and by courtesy in Neurology, and in Psychiatry and Behavioral Sciences at Stanford University.
The active zone or synaptic active zone is a term first used by Couteaux and Pecot-Dechavassinein in 1970 to define the site of neurotransmitter release. Two neurons make near contact through structures called synapses allowing them to communicate with each other. As shown in the adjacent diagram, a synapse consists of the presynaptic bouton of one neuron which stores vesicles containing neurotransmitter, and a second, postsynaptic neuron which bears receptors for the neurotransmitter, together with a gap between the two called the synaptic cleft. When an action potential reaches the presynaptic bouton, the contents of the vesicles are released into the synaptic cleft and the released neurotransmitter travels across the cleft to the postsynaptic neuron and activates the receptors on the postsynaptic membrane.
Stuart Graham Cull-Candy is a British neuroscientist. He holds the Gaddum Chair of Pharmacology and a personal Chair in Neuroscience at University College London. He is also a member of the Faculty of 1000 and holds a Royal Society - Wolfson Research position.
Victor Percy Whittaker was a British biochemist who pioneered studies on the subcellular fractionation of the brain. He did this by isolating synaptosomes and synaptic vesicles from the mammalian brain and demonstrating that synaptic vesicles store the neurotransmitter acetylcholine.
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