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Marcelle Lapicque
Marcelle de Heredia Lapicque (17 July 1873 – 1962) was a French neurophysiologist known for her research on nerve impulses (chronaxie) and the effects of poisons, especially strychnine, on chronaxie. She supervised the Laboratoire des Hautes-Études General Physiology laboratory, and published over eighty papers. Life Lapicque was born on 17 July 1873 in Paris. Her father was a landowner and Paris municipal councillor, French politician Severiano de Heredia. She studied science at the University of Paris, and was a fellow student of Louis Lapicque, who she had a son with in 1898, although they were not married until 1902. Lapicque completed her dissertation on nerve impulses, in which she was supervised by her husband. She was in charge of the Laboratoire des Hautes-Études General Physiology laboratory until her death. Marcelle Lapicque, though overshadowed in histories of science by her husband, was an influential scientist in her own right, publishing many papers as sole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurophysiology
Neurophysiology is a branch of physiology and neuroscience concerned with the functions of the nervous system and their mechanisms. The term ''neurophysiology'' originates from the Greek word ''νεῦρον'' ("nerve") and ''physiology'' (which is, in turn, derived from the Greek ''φύσις'', meaning "nature", and ''-λογία'', meaning "knowledge"). Neurophysiology has applications in the prevention, diagnosis, and treatment of many neurological and psychiatric diseases. Neurophysiological techniques are also used by clinical neurophysiologists to diagnose and monitor patients with neurological diseases. The field involves all levels of nervous system function, from molecules and cells to systems and whole organisms. Areas of study include: * The electrochemical properties of neurons * Function and regulation of proteins in neurons and glia * Metabolic reactions relevant to neural function * Cell signalling in the nervous system * Neurotransmission and synaptic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Impulses
An action potential (also known as a nerve impulse or "spike" when in a neuron) is a series of quick changes in voltage across a cell membrane. An action potential occurs when the membrane potential of a specific cell rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of excitable cells, which include animal cells like neurons and muscle cells, as well as some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells. In neurons, action potentials play a central role in cell–cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses, or to motor cells or glands. In other types of cells, their main func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronaxie
Chronaxie is the minimum time required for an electric current double the strength of the rheobase to stimulate a muscle or a neuron. Rheobase is the lowest intensity with indefinite pulse duration which just stimulated muscles or nerves. Chronaxie is dependent on the density of voltage-gated sodium channels in the cell, which affect that cell's excitability. Chronaxie varies across different types of tissue: fast-twitch muscles have a lower chronaxie, slow-twitch muscles have a higher one. Chronaxie is the tissue-excitability parameter that permits choice of the optimum stimulus pulse duration for stimulation of any excitable tissue. Chronaxie (c) is the Lapicque descriptor of the stimulus pulse duration for a current of twice rheobasic (b) strength, which is the threshold current for an infinitely long-duration stimulus pulse. Lapicque showed that these two quantities (c,b) define the strength-duration curve for current: I = b(1+c/d), where d is the pulse duration. However, ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strychnine
Strychnine (, , American English, US chiefly ) is a highly toxicity, toxic, colorless, bitter, crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine, when inhaled, swallowed, or absorbed through the eyes or mouth, causes Strychnine poisoning, poisoning which results in muscular convulsions and eventually death through asphyxia. While it is no longer used medicinally, it was used historically in small doses to strengthen muscle contractions, such as a heart and bowel stimulant and performance-enhancing drug. The most common source is from the seeds of the ''Strychnos nux-vomica'' tree. Biosynthesis Strychnine is a terpene indole alkaloid belonging to the ''Strychnos'' family of ''Corynanthe'' alkaloids, and it is derived from tryptamine and secologanin. The biosynthesis of strychnine was solved in 2022. The enzyme, strictosidine synthase, catalyzes the condensation of tryptamine and secologanin, followed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Severiano De Heredia
Severiano de Heredia (8 November 1836 – 9 February 1901) was a Cuban-born biracial politician, a freemason, a left-wing republican, naturalized as French in 1870, who was president of the municipal council of Paris from 1 August 1879 to 12 February 1880, making him the only native of the American continent who was appointed on relevant post of the Mayor of Paris and the first mayor of African descent of a Western world capital. In 1880, he succeeded Victor Hugo in the presidency of the Philotechnical Association. He served in the Chamber of Deputies from 1881 to 1889 and was briefly Minister of Public Works for the cabinet of Maurice Rouvier in 1887, at the time when the Eiffel Tower first started being built, where he planned and oversaw the construction of some of the finest French highways. He is believed to be a cousin of the famous French poet José-Maria de Heredia. Biography Personal life Severiano de Heredia was born in Matanzas, Cuba, to Henri de Heredia and mulatta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Lapicque
Louis Édouard Lapicque (1 August 1866 – 6 December 1952) was a French neuroscientist, socialist activist, antiboulangist, dreyfusard and freemason who was very influential in the early 20th century. One of his main contributions was to propose the integrate-and-fire model of the neuron in a seminal article published in 1907. Today, this model of the neuron is still one of the most popular models in computational neuroscience for both cellular and neural networks A neural network is a group of interconnected units called neurons that send signals to one another. Neurons can be either Cell (biology), biological cells or signal pathways. While individual neurons are simple, many of them together in a netwo ... studies, as well as in mathematical neuroscience because of its simplicity. A review article was published for the centenary of the original Lapicque's 1907 paper - this review also contains an English translation of the original paper. His wife, Marcelle Lapicque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Société De Biologie
The Société de biologie () is a learned society founded in Paris in 1848. The society was conceived during the French Revolution of 1848. The members of the society held regular meetings and published the proceedings in a new scientific journal. The founding members of the society included Claude Bernard, the naturalist Charles-Philippe Robin, and the surgeon Eugène Follin. Its first president was the doctor and dermatologist Dermatology is the branch of medicine dealing with the skin.''Random House Webster's Unabridged Dictionary.'' Random House, Inc. 2001. Page 537. . It is a speciality with both medical and surgical aspects. A dermatologist is a specialist medi ... Pierre Rayer. Bernard was unanimously elected president of the society in 1867 upon Rayer's death. Historian Mirko Grmek said the society brought together the best physiologists and naturalists in Paris, and that Bernard regularly attended the weekly meetings. During 1849 he spoke at nearly all the sessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean Baptiste Perrin
Jean Baptiste Perrin (; 30 September 1870 – 17 April 1942) was a French atomic physicist who, in his studies of the Brownian motion of minute particles suspended in liquids (sedimentation equilibrium), verified Albert Einstein's explanation of this phenomenon and thereby confirmed the atomic nature of matter. For this achievement, he was honoured with the Nobel Prize in Physics in 1926. Biography Early years Born in Lille, France, Perrin attended the École normale supérieure, the elite ''grande école'' in Paris. He became an assistant at the school during the period of 1894–97 when he began the study of cathode rays and X-rays. He was awarded the degree of '' docteur ès sciences'' in 1897. In the same year, he was appointed as a lecturer in physical chemistry at the Sorbonne, Paris. He became a professor at the university in 1910, holding this post until the German occupation of France during World War II. Research and achievements In 1895, Perrin showed that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Neuroscientists
French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), a British rock band * "French" (episode), a live-action episode of ''The Super Mario Bros. Super Show!'' * ''Française'' (film), a 2008 film * French Stewart (born 1964), American actor Other uses * French (surname), a surname (including a list of people with the name) * French (tunic), a type of military jacket or tunic * French's, an American brand of mustard condiment * French (catheter scale), a unit of measurement * French Defence, a chess opening * French kiss, a type of kiss See also * France (other) France is a country in western Europe. France may also refer to: People * France (name), including a list of people with the given name or surname * Anatole France, pen name of French writer François-Anatole Thibault ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
