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Monday, August 23, 2021

Futurism

From Wikipedia, the free encyclopedia

Gino Severini, 1912, Dynamic Hieroglyphic of the Bal Tabarin, oil on canvas with sequins, 161.6 x 156.2 cm (63.6 x 61.5 in.), Museum of Modern Art, New York
 
Italian futurists Luigi Russolo, Carlo Carrà, Filippo Tommaso Marinetti, Umberto Boccioni and Gino Severini in front of Le Figaro, Paris, February 9, 1912

Futurism (Italian: Futurismo) was an artistic and social movement that originated in Italy in the early 20th century which later also developed in Russia. It emphasized dynamism, speed, technology, youth, violence, and objects such as the car, the airplane, and the industrial city. Its key figures were the Italians Filippo Tommaso Marinetti, Umberto Boccioni, Carlo Carrà, Fortunato Depero, Gino Severini, Giacomo Balla, and Luigi Russolo. It glorified modernity and aimed to liberate Italy from the weight of its past. Important Futurist works included Marinetti's Manifesto of Futurism, Boccioni's sculpture Unique Forms of Continuity in Space, Balla's painting Abstract Speed + Sound, and Russolo's The Art of Noises.

Although it was largely an Italian phenomenon, there were parallel movements in Russia, where some Russian Futurists would later go on to found groups of their own; other countries either had a few Futurists or had movements inspired by Futurism. The Futurists practiced in every medium of art, including painting, sculpture, ceramics, graphic design, industrial design, interior design, urban design, theatre, film, fashion, textiles, literature, music, architecture, and even cooking.

To some extent Futurism influenced the art movements Art Deco, Constructivism, Surrealism, and Dada, and to a greater degree Precisionism, Rayonism, and Vorticism.

Italian Futurism

Umberto Boccioni, Unique Forms of Continuity in Space (1913)

Futurism is an avant-garde movement founded in Milan in 1909 by the Italian poet Filippo Tommaso Marinetti. Marinetti launched the movement in his Manifesto of Futurism, which he published for the first time on 5 February 1909 in La gazzetta dell'Emilia, an article then reproduced in the French daily newspaper Le Figaro on Saturday 20 February 1909. He was soon joined by the painters Umberto Boccioni, Carlo Carrà, Giacomo Balla, Gino Severini and the composer Luigi Russolo. Marinetti expressed a passionate loathing of everything old, especially political and artistic tradition. "We want no part of it, the past", he wrote, "we the young and strong Futurists!" The Futurists admired speed, technology, youth and violence, the car, the airplane and the industrial city, all that represented the technological triumph of humanity over nature, and they were passionate nationalists. They repudiated the cult of the past and all imitation, praised originality, "however daring, however violent", bore proudly "the smear of madness", dismissed art critics as useless, rebelled against harmony and good taste, swept away all the themes and subjects of all previous art, and gloried in science.

Publishing manifestos was a feature of Futurism, and the Futurists (usually led or prompted by Marinetti) wrote them on many topics, including painting, architecture, music, literature, photography, religion, women, fashion and cuisine.

The founding manifesto did not contain a positive artistic programme, which the Futurists attempted to create in their subsequent Technical Manifesto of Futurist Painting (published in Italian as a leaflet by Poesia, Milan, 11 April 1910). This committed them to a "universal dynamism", which was to be directly represented in painting. Objects in reality were not separate from one another or from their surroundings: "The sixteen people around you in a rolling motor bus are in turn and at the same time one, ten four three; they are motionless and they change places. ... The motor bus rushes into the houses which it passes, and in their turn the houses throw themselves upon the motor bus and are blended with it."

The Futurist painters were slow to develop a distinctive style and subject matter. In 1910 and 1911 they used the techniques of Divisionism, breaking light and color down into a field of stippled dots and stripes, which had been adopted from Divisionism by Giovanni Segantini and others. Later, Severini, who lived in Paris, attributed their backwardness in style and method at this time to their distance from Paris, the centre of avant-garde art. Cubism contributed to the formation of Italian Futurism's artistic style. Severini was the first to come into contact with Cubism and following a visit to Paris in 1911 the Futurist painters adopted the methods of the Cubists. Cubism offered them a means of analysing energy in paintings and expressing dynamism.

They often painted modern urban scenes. Carrà's Funeral of the Anarchist Galli (1910–11) is a large canvas representing events that the artist had himself been involved in, in 1904. The action of a police attack and riot is rendered energetically with diagonals and broken planes. His Leaving the Theatre (1910–11) uses a Divisionist technique to render isolated and faceless figures trudging home at night under street lights.

Boccioni's The City Rises (1910) represents scenes of construction and manual labour with a huge, rearing red horse in the centre foreground, which workmen struggle to control. His States of Mind, in three large panels, The Farewell, Those who Go, and Those Who Stay, "made his first great statement of Futurist painting, bringing his interests in Bergson, Cubism and the individual's complex experience of the modern world together in what has been described as one of the 'minor masterpieces' of early twentieth century painting." The work attempts to convey feelings and sensations experienced in time, using new means of expression, including "lines of force", which were intended to convey the directional tendencies of objects through space, "simultaneity", which combined memories, present impressions and anticipation of future events, and "emotional ambience" in which the artist seeks by intuition to link sympathies between the exterior scene and interior emotion.

Boccioni's intentions in art were strongly influenced by the ideas of Bergson, including the idea of intuition, which Bergson defined as a simple, indivisible experience of sympathy through which one is moved into the inner being of an object to grasp what is unique and ineffable within it. The Futurists aimed through their art thus to enable the viewer to apprehend the inner being of what they depicted. Boccioni developed these ideas at length in his book, Pittura scultura Futuriste: Dinamismo plastico (Futurist Painting Sculpture: Plastic Dynamism) (1914).

Balla's Dynamism of a Dog on a Leash (1912) exemplifies the Futurists' insistence that the perceived world is in constant movement. The painting depicts a dog whose legs, tail and leash—and the feet of the woman walking it—have been multiplied to a blur of movement. It illustrates the precepts of the Technical Manifesto of Futurist Painting that, "On account of the persistency of an image upon the retina, moving objects constantly multiply themselves; their form changes like rapid vibrations, in their mad career. Thus a running horse has not four legs, but twenty, and their movements are triangular." His Rhythm of the Bow (1912) similarly depicts the movements of a violinist's hand and instrument, rendered in rapid strokes within a triangular frame.

The adoption of Cubism determined the style of much subsequent Futurist painting, which Boccioni and Severini in particular continued to render in the broken colors and short brush-strokes of divisionism. But Futurist painting differed in both subject matter and treatment from the quiet and static Cubism of Picasso, Braque and Gris. As the art critic Robert Hughes observed, "In Futurism, the eye is fixed and the object moves, but it is still the basic vocabulary of Cubism—fragmented and overlapping planes". While there were Futurist portraits: Carrà's Woman with Absinthe (1911), Severini's Self-Portrait (1912), and Boccioni's Matter (1912), it was the urban scene and vehicles in motion that typified Futurist painting; Boccioni's The Street Enters the House (1911), Severini's Dynamic Hieroglyph of the Bal Tabarin (1912), and Russolo's Automobile at Speed (1913)

Umberto Boccioni, 1913, Dynamism of a Cyclist (Dinamismo di un ciclista), oil on canvas, 70 x 95 cm, Gianni Mattioli Collection, on long-term loan to the Peggy Guggenheim Collection, Venice
 
Joseph Stella, Battle of Lights, Coney Island, 1913–14, oil on canvas, 195.6 × 215.3 cm (77 × 84.75 in), Yale University Art Gallery, New Haven, CT

The Futurists held their first exhibition outside of Italy in 1912 at the Bernheim-Jeune gallery, Paris, which included works by Umberto Boccioni, Gino Severini, Carlo Carrà, Luigi Russolo and Giacomo Balla.

In 1912 and 1913, Boccioni turned to sculpture to translate into three dimensions his Futurist ideas. In Unique Forms of Continuity in Space (1913) he attempted to realise the relationship between the object and its environment, which was central to his theory of "dynamism". The sculpture represents a striding figure, cast in bronze posthumously and exhibited in the Tate Modern. (It now appears on the national side of Italian 20 eurocent coins). He explored the theme further in Synthesis of Human Dynamism (1912), Speeding Muscles (1913) and Spiral Expansion of Speeding Muscles (1913). His ideas on sculpture were published in the Technical Manifesto of Futurist Sculpture In 1915 Balla also turned to sculpture making abstract "reconstructions", which were created out of various materials, were apparently moveable and even made noises. He said that, after making twenty pictures in which he had studied the velocity of automobiles, he understood that "the single plane of the canvas did not permit the suggestion of the dynamic volume of speed in depth ... I felt the need to construct the first dynamic plastic complex with iron wires, cardboard planes, cloth and tissue paper, etc."

In 1914, personal quarrels and artistic differences between the Milan group, around Marinetti, Boccioni, and Balla, and the Florence group, around Carrà, Ardengo Soffici (1879–1964) and Giovanni Papini (1881–1956), created a rift in Italian Futurism. The Florence group resented the dominance of Marinetti and Boccioni, whom they accused of trying to establish "an immobile church with an infallible creed", and each group dismissed the other as passéiste.

Futurism had from the outset admired violence and was intensely patriotic. The Futurist Manifesto had declared, "We will glorify war—the world's only hygiene—militarism, patriotism, the destructive gesture of freedom-bringers, beautiful ideas worth dying for, and scorn for woman." Although it owed much of its character and some of its ideas to radical political movements, it was not much involved in politics until the autumn of 1913. Then, fearing the re-election of Giolitti, Marinetti published a political manifesto. In 1914 the Futurists began to campaign actively against the Austro-Hungarian empire, which still controlled some Italian territories, and Italian neutrality between the major powers. In September, Boccioni, seated in the balcony of the Teatro dal Verme in Milan, tore up an Austrian flag and threw it into the audience, while Marinetti waved an Italian flag. When Italy entered the First World War in 1915, many Futurists enlisted. The experience of the war marked several Futurists, particularly Marinetti, who fought in the mountains of Trentino at the border of Italy and Austria-Hungary, actively engaging in propaganda. The combat experience also influenced Futurist music.

The outbreak of war disguised the fact that Italian Futurism had come to an end. The Florence group had formally acknowledged their withdrawal from the movement by the end of 1914. Boccioni produced only one war picture and was killed in 1916. Severini painted some significant war pictures in 1915 (e.g. War, Armored Train, and Red Cross Train), but in Paris turned towards Cubism and post-war was associated with the Return to Order.

After the war, Marinetti revived the movement. This revival was called il secondo Futurismo (Second Futurism) by writers in the 1960s. The art historian Giovanni Lista has classified Futurism by decades: "Plastic Dynamism" for the first decade, "Mechanical Art" for the 1920s, "Aeroaesthetics" for the 1930s.

Russian Futurism

Group photograph of several Russian Futurists, published in their manifesto A Slap in the Face of Public Taste. Left to right: Aleksei Kruchyonykh, Vladimir Burliuk, Vladimir Mayakovsky, David Burliuk, and Benedikt Livshits.

Russian Futurism was a movement of literature and the visual arts, involving various Futurist groups. The poet Vladimir Mayakovsky was a prominent member of the movement, as were Velimir Khlebnikov and Aleksei Kruchyonykh; visual artists such as David Burliuk, Mikhail Larionov, Natalia Goncharova, Lyubov Popova, and Kazimir Malevich found inspiration in the imagery of Futurist writings, and were writers themselves. Poets and painters collaborated on theatre production such as the Futurist opera Victory Over the Sun, with texts by Kruchenykh, music by Mikhail Matyushin, and sets by Malevich.

The main style of painting was Cubo-Futurism, extant during the 1910s. Cubo-Futurism combines the forms of Cubism with the Futurist representation of movement; like their Italian contemporaries, the Russian Futurists were fascinated with dynamism, speed and the restlessness of modern urban life.

The Russian Futurists sought controversy by repudiating the art of the past, saying that Pushkin and Dostoevsky should be "heaved overboard from the steamship of modernity". They acknowledged no authority and professed not to owe anything even to Marinetti, whose principles they had earlier adopted, most of whom obstructed him when he came to Russia to proselytize in 1914.

The movement began to decline after the revolution of 1917. The Futurists either stayed, were persecuted, or left the country. Popova, Mayakovsky and Malevich became part of the Soviet establishment and the brief Agitprop movement of the 1920s; Popova died of a fever, Malevich would be briefly imprisoned and forced to paint in the new state-approved style, and Mayakovsky committed suicide on April 14, 1930.

Architecture

The Futurist architect Antonio Sant'Elia expressed his ideas of modernity in his drawings for La Città Nuova (The New City) (1912–1914). This project was never built and Sant'Elia was killed in the First World War, but his ideas influenced later generations of architects and artists. The city was a backdrop onto which the dynamism of Futurist life is projected. The city had replaced the landscape as the setting for the exciting modern life. Sant'Elia aimed to create a city as an efficient, fast-paced machine. He manipulates light and shape to emphasize the sculptural quality of his projects. Baroque curves and encrustations had been stripped away to reveal the essential lines of forms unprecedented from their simplicity. In the new city, every aspect of life was to be rationalized and centralized into one great powerhouse of energy. The city was not meant to last, and each subsequent generation was expected to build their own city rather than inheriting the architecture of the past.

Futurist architects were sometimes at odds with the Fascist state's tendency towards Roman imperial-classical aesthetic patterns. Nevertheless, several Futurist buildings were built in the years 1920–1940, including public buildings such as railway stations, maritime resorts and post offices. Examples of Futurist buildings still in use today are Trento railway station, built by Angiolo Mazzoni, and the Santa Maria Novella station in Florence. The Florence station was designed in 1932 by the Gruppo Toscano (Tuscan Group) of architects, which included Giovanni Michelucci and Italo Gamberini, with contributions by Mazzoni.

Music

Futurist music rejected tradition and introduced experimental sounds inspired by machinery, and would influence several 20th-century composers.

Francesco Balilla Pratella joined the Futurist movement in 1910 and wrote a Manifesto of Futurist Musicians in which he appealed to the young (as had Marinetti), because only they could understand what he had to say. According to Pratella, Italian music was inferior to music abroad. He praised the "sublime genius" of Wagner and saw some value in the work of other contemporary composers, for example Richard Strauss, Elgar, Mussorgsky, and Sibelius. By contrast, the Italian symphony was dominated by opera in an "absurd and anti-musical form". The conservatories was said to encourage backwardness and mediocrity. The publishers perpetuated mediocrity and the domination of music by the "rickety and vulgar" operas of Puccini and Umberto Giordano. The only Italian Pratella could praise was his teacher Pietro Mascagni, because he had rebelled against the publishers and attempted innovation in opera, but even Mascagni was too traditional for Pratella's tastes. In the face of this mediocrity and conservatism, Pratella unfurled "the red flag of Futurism, calling to its flaming symbol such young composers as have hearts to love and fight, minds to conceive, and brows free of cowardice."

Luigi Russolo (1885–1947) wrote The Art of Noises (1913), an influential text in 20th-century musical aesthetics. Russolo used instruments he called intonarumori, which were acoustic noise generators that permitted the performer to create and control the dynamics and pitch of several different types of noises. Russolo and Marinetti gave the first concert of Futurist music, complete with intonarumori, in 1914. However they were prevented from performing in many major European cities by the outbreak of war.

Futurism was one of several 20th-century movements in art music that paid homage to, included or imitated machines. Ferruccio Busoni has been seen as anticipating some Futurist ideas, though he remained wedded to tradition. Russolo's intonarumori influenced Stravinsky, Arthur Honegger, George Antheil, Edgar Varèse, Stockhausen and John Cage. In Pacific 231, Honegger imitated the sound of a steam locomotive. There are also Futurist elements in Prokofiev's The Steel Step and in his Second Symphony.

Most notable in this respect, however, is the American George Antheil. His fascination with machinery is evident in his Airplane Sonata, Death of the Machines, and the 30-minute Ballet Mécanique. The Ballet Mécanique was originally intended to accompany an experimental film by Fernand Léger, but the musical score is twice the length of the film and now stands alone. The score calls for a percussion ensemble consisting of three xylophones, four bass drums, a tam-tam, three airplane propellers, seven electric bells, a siren, two "live pianists", and sixteen synchronized player pianos. Antheil's piece was the first to synchronize machines with human players and to exploit the difference between what machines and humans can play.

Dance

The Futuristic movement also influenced the concept of dance. Indeed, dancing was interpreted as an alternative way of expressing man's ultimate fusion with the machine. The altitude of a flying plane, the power of a car's motor and the roaring loud sounds of complex machinery were all signs of man's intelligence and excellence which the art of dance had to emphasize and praise. This type of dance is considered futuristic since it disrupts the referential system of traditional, classical dance and introduces a different style, new to the sophisticated bourgeois audience. The dancer no longer performs a story, a clear content, that can be read according to the rules of ballet. One of the most famous futuristic dancers was the Italian Giannina Censi [it]. Trained as a classical ballerina, she is known for her "Aerodanze" and continued to earn her living by performing in classical and popular productions. She describes this innovative form of dance as the result of a deep collaboration with Marinetti and his poetry. Through these words, she explains: " I launched this idea of the aerial-futurist poetry with Marinetti, he himself declaiming the poetry. A small stage of a few square meters;... I made myself a satin costume with a helmet; everything that the plane did had to be expressed by my body. It flew and, moreover, it gave the impression of these wings that trembled, of the apparatus that trembled,... And the face had to express what the pilot felt."

Literature

Futurism as a literary movement made its official debut with F.T. Marinetti's Manifesto of Futurism (1909), as it delineated the various ideals Futurist poetry should strive for. Poetry, the predominate medium of Futurist literature, can be characterized by its unexpected combinations of images and hyper-conciseness (not to be confused with the actual length of the poem). The Futurists called their style of poetry parole in libertà (word autonomy), in which all ideas of meter were rejected and the word became the main unit of concern. In this way, the Futurists managed to create a new language free of syntax punctuation, and metrics that allowed for free expression.

Theater also has an important place within the Futurist universe. Works in this genre have scenes that are few sentences long, have an emphasis on nonsensical humor, and attempt to discredit the deep rooted traditions via parody and other devaluation techniques.

There are a number of examples of Futurist novels from both the initial period of Futurism and the neo-Futurist period, from Marinetti himself to a number of lesser known Futurists, such as Primo Conti, Ardengo Soffici and Giordano Bruno Sanzin (Zig Zag, Il Romanzo Futurista edited by Alessandro Masi, 1995). They are very diverse in style, with very little recourse to the characteristics of Futurist Poetry, such as 'parole in libertà'. Arnaldo Ginna's 'Le locomotive con le calze'(Trains with socks on) plunges into a world of absurd nonsense, childishly crude. His brother Bruno Corra wrote in Sam Dunn è morto (Sam Dunn is Dead) a masterpiece of Futurist fiction, in a genre he himself called 'Synthetic' characterized by compression, and precision; it is a sophisticated piece that rises above the other novels through the strength and pervasiveness of its irony. Science Fiction novels play an important role in Futurist literature.

Film

When interviewed about her favorite film of all times, famed movie critic Pauline Kael stated that the director Dimitri Kirsanoff, in his silent experimental film Ménilmontant "developed a technique that suggests the movement known in painting as Futurism".

Thaïs ("Thaïs"), directed by Anton Giulio Bragaglia (1917), is the only surviving of the 1910s Italian futurist cinema to date (35 min. of the original 70 min.).

Female Futurists

Within F.T. Marinetti's The Founding and Manifesto of Futurism, two of his tenets briefly highlight his hatred for women under the pretense that it fuels the Futurist movement's visceral nature:

9. We intend to glorify war—the only hygiene of the world—militarism, patriotism, the destructive gesture of anarchists, beautiful ideas worth dying for, and contempt for woman.
10. We intend to destroy museums, libraries, academics of every sort and to fight against moralism, feminism, and every utilitarian opportunistic cowardice.

Marinetti would begin to contradict himself when, in 1911, he called Luisa, Marchesa Casati a Futurist; he dedicated a portrait of himself painted by Carrà to her, the said dedication declaring Casati as a Futurist being pasted on the canvas itself.

In 1912, only three years after the Manifesto of Futurism was published, Valentine de Saint-Point responded to Marinetti's claims in her Manifesto of the Futurist Woman (Response to F.T. Marinetti.) Marinetti even later referred to her as "the 'first futurist woman.'" Her manifesto begins with a misanthropic tone by presenting how men and women are equal and both deserve contempt. She instead suggests that rather than the binary being limited to men and women, it should be replaced with "femininity and masculinity"; ample cultures and individuals should possess elements of both. Yet, she still embraces the core values of Futurism, especially its focus on "virility" and "brutality". Saint-Point uses this as a segue into her antifeminist argument—giving women equal rights destroys their innate "potency" to strive for a better, more fulfilling life.

In Russian Futurist and Cubo-Futurist circles, however, from the start, there was a higher percentage of women participants than in Italy; examples of major female Futurists are Natalia Goncharova, Aleksandra Ekster, and Lyubov Popova. Although Marinetti expressed his approval of Olga Rozanova's paintings during his 1914 lecture tour of Russia, it is possible that the women painters' negative reaction to the said tour may have largely been due to his misogyny.

Despite the chauvinistic nature of the Italian Futurist program, many serious professional female artists adopted the style, especially so after the end of the first World War. Notably among these female futurists is F.T Marinetti's own wife Benedetta Cappa Marinetti, whom he had met in 1918 and exchanged a series of letters discussing each of their respective work in Futurism. Letters continued to be exchanged between the two with F.T Marinetti often complimenting Benedetta - the single name she was best known as - on her genius. In a letter dated August 16, 1919, Marinetti wrote to Benedetta "Do not forget your promise to work. You must carry your genius to its ultimate splendor. Every day." Although many of Benedetta's paintings were exhibited in major Italian exhibitions like the 1930-1936 Venice Biennales (in which she was the first woman to have her art displayed since the exhibition's founding in 1895), the 1935 Rome Quadriennale and several other futurist exhibitions, she was oft overshadowed in her work by her husband. The first introduction of Benedetta's feminist convictions regarding futurism is in the form of a public dialogue in 1925 (with a L.R Cannonieri) concerning the role of women in society. Benedetta was also one of the first to paint in Aeropittura, an abstract and futurist art style of landscape from the view of an airplane.

1920s and 1930s

Joseph Stella, 1919–20, Brooklyn Bridge, oil on canvas, 215.3 x 194.6 cm, Yale University Art Gallery

Many Italian Futurists supported Fascism in the hope of modernizing a country divided between the industrialising north and the rural, archaic South. Like the Fascists, the Futurists were Italian nationalists, radicals, admirers of violence, and were opposed to parliamentary democracy. Marinetti founded the Futurist Political Party (Partito Politico Futurista) in early 1918, which was absorbed into Benito Mussolini's Fasci Italiani di Combattimento in 1919, making Marinetti one of the first members of the National Fascist Party. He opposed Fascism's later exaltation of existing institutions, calling them "reactionary", and walked out of the 1920 Fascist party congress in disgust, withdrawing from politics for three years; but he supported Italian Fascism until his death in 1944. The Futurists' association with Fascism after its triumph in 1922 brought them official acceptance in Italy and the ability to carry out important work, especially in architecture. After the Second World War, many Futurist artists had difficulty in their careers because of their association with a defeated and discredited regime.

Marinetti sought to make Futurism the official state art of Fascist Italy but failed to do so. Mussolini chose to give patronage to numerous styles and movements in order to keep artists loyal to the regime. Opening the exhibition of art by the Novecento Italiano group in 1923, he said, "I declare that it is far from my idea to encourage anything like a state art. Art belongs to the domain of the individual. The state has only one duty: not to undermine art, to provide humane conditions for artists, to encourage them from the artistic and national point of view." Mussolini's mistress, Margherita Sarfatti, who was as able a cultural entrepreneur as Marinetti, successfully promoted the rival Novecento group, and even persuaded Marinetti to sit on its board. Although in the early years of Italian Fascism modern art was tolerated and even embraced, towards the end of the 1930s, right-wing Fascists introduced the concept of "degenerate art" from Germany to Italy and condemned Futurism.

Marinetti made numerous moves to ingratiate himself with the regime, becoming less radical and avant-garde with each. He moved from Milan to Rome to be nearer the centre of things. He became an academician despite his condemnation of academies, married despite his condemnation of marriage, promoted religious art after the Lateran Treaty of 1929 and even reconciled himself to the Catholic Church, declaring that Jesus was a Futurist.

An example of Futurist design: "Skyscraper Lamp", by the Italian architect Arnaldo dell'Ira, 1929

Although Futurism mostly became identified with Fascism, it had leftist and anti-Fascist supporters. They tended to oppose Marinetti's artistic and political direction of the movement, and in 1924 the socialists, communists and anarchists walked out of the Milan Futurist Congress. The anti-Fascist voices in Futurism were not completely silenced until the annexation of Abyssinia and the Italo-German Pact of Steel in 1939. This association of Fascists, socialists and anarchists in the Futurist movement, which may seem odd today, can be understood in terms of the influence of Georges Sorel, whose ideas about the regenerative effect of political violence had adherents right across the political spectrum.

Aeropainting

Aeropainting (aeropittura) was a major expression of the second generation of Futurism beginning in 1926. The technology and excitement of flight, directly experienced by most aeropainters, offered aeroplanes and aerial landscape as new subject matter. Aeropainting was varied in subject matter and treatment, including realism (especially in works of propaganda), abstraction, dynamism, quiet Umbrian landscapes, portraits of Mussolini (e.g. Dottori's Portrait of il Duce), devotional religious paintings, decorative art, and pictures of planes.

Aeropainting was launched in a manifesto of 1929, Perspectives of Flight, signed by Benedetta, Depero, Dottori, Fillìa, Marinetti, Prampolini, Somenzi and Tato (Guglielmo Sansoni). The artists stated that "The changing perspectives of flight constitute an absolutely new reality that has nothing in common with the reality traditionally constituted by a terrestrial perspective" and that "Painting from this new reality requires a profound contempt for detail and a need to synthesise and transfigure everything." Crispolti identifies three main "positions" in aeropainting: "a vision of cosmic projection, at its most typical in Prampolini's 'cosmic idealism' ... ; a 'reverie' of aerial fantasies sometimes verging on fairy-tale (for example in Dottori ...); and a kind of aeronautical documentarism that comes dizzyingly close to direct celebration of machinery (particularly in Crali, but also in Tato and Ambrosi)."

Eventually there were over a hundred aeropainters. Major figures include Fortunato Depero, Marisa Mori, Enrico Prampolini, Gerardo Dottori, Mino Delle Site and Crali. Crali continued to produce aeropittura up until the 1980s.

Legacy

Futurism influenced many other twentieth-century art movements, including Art Deco, Vorticism, Constructivism, Surrealism, Dada, and much later Neo-Futurism and the Grosvenor School linocut artists. Futurism as a coherent and organized artistic movement is now regarded as extinct, having died out in 1944 with the death of its leader Marinetti.

Nonetheless, the ideals of Futurism remain as significant components of modern Western culture; the emphasis on youth, speed, power and technology finding expression in much of modern commercial cinema and culture. Ridley Scott consciously evoked the designs of Sant'Elia in Blade Runner. Echoes of Marinetti's thought, especially his "dreamt-of metallization of the human body", are still strongly prevalent in Japanese culture, and surface in manga/anime and the works of artists such as Shinya Tsukamoto, director of the Tetsuo (lit. "Ironman") films. Futurism has produced several reactions, including the literary genre of cyberpunk—in which technology was often treated with a critical eye—whilst artists who came to prominence during the first flush of the Internet, such as Stelarc and Mariko Mori, produce work which comments on Futurist ideals. and the art and architecture movement Neo-Futurism in which technology is considered a driver to a better quality of life and sustainability values.

A revival of sorts of the Futurist movement in theatre began in 1988 with the creation of the Neo-Futurist style in Chicago, which utilizes Futurism's focus on speed and brevity to create a new form of immediate theatre. Currently, there are active Neo-Futurist troupes in Chicago, New York, San Francisco, and Montreal.

Futurist ideas have been a major influence in Western popular music; examples include ZTT Records, named after Marinetti's poem Zang Tumb Tumb; the band Art of Noise, named after Russolo's manifesto The Art of Noises; and the Adam and the Ants single "Zerox", the cover featuring a photograph by Bragaglia. Influences can also be discerned in dance music since the 1980s.

Japanese Composer Ryuichi Sakamoto's 1986 album "Futurista" was inspired by the movement. It features a speech from Tommaso Marinetti in the track 'Variety Show'.

In 2009, Italian director Marco Bellocchio included Futurist art in his feature film Vincere.

In 2014, the Solomon R. Guggenheim Museum featured the exhibition "Italian Futurism, 1909–1944: Reconstructing the Universe". This was the first comprehensive overview of Italian Futurism to be presented in the United States.

Estorick Collection of Modern Italian Art is a museum in London, with a collection solely centered around modern Italian artists and their works. It is best known for its large collection of Futurist paintings.

Futurism, Cubism, press articles and reviews


Subitism

From Wikipedia, the free encyclopedia

The term subitism points to sudden awakening, the idea that insight into Buddha-nature, or the nature of mind, is "sudden," c.q. "in one glance," "uncovered all together," or "together, completely, simultaneously," in contrast to "successively or being uncovered one after the other." It may be posited as opposite to gradualism, the original Buddhist approach which says that following the dharma can be achieved only step by step, through an arduous practice.

The application of the term "subitism" to Buddhism is derived from the French illumination subite (sudden awakening), contrasting with 'illumination graduelle' (gradual awakening). It gained currency in this use in English from the work of sinologist Paul Demiéville. His 1947 work 'Mirror of the Mind' was widely read in the U.S. It inaugurated a series by him on subitism and gradualism.

The Chinese term tun, as used in tun-wu, translated as "subite," sudden, has a broader meaning than "sudden." It is more apt translated as "in one glance," "uncovered all together," or "together, completely, simultaneously," in contrast to "successively or being uncovered one after the other." It means that all aspects of Buddhist practice are realized, or actualized, simultaneously, and not one after another as in a gradual or linear school curriculum. Specifically, the defilements are not erased gradually, by good works, but simultaneously.

Subitizing, also derived from the Latin adjective subitus, is the rapid, accurate, and confident judgments of numbers performed for small numbers of items. It is important to be aware subitism can also be used in this context.

Tun wu in Chinese Buddhism

Chan

The distinction between sudden and gradual awakening has its roots in Indian Buddhism. It was first introduced in China in the beginning of the 5th century CE by Tao Sheng. The term became of central importance in Chan Buddhism, where it is used to denote the doctrinal position that awakening, the comprehension or realization of the Buddhist teachings, happens simultaneously, and is not the fruit of a gradual accretion or realisation.

Shenhui

In the 8th century the distinction became part of a struggle for influence at the Chinese court by Shenhui, a student of Huineng. Hereafter "sudden enlightenment" became one of the hallmarks of Chan Buddhism, though the sharp distinction was softened by subsequent generations of practitioners.

This softening is reflected in the Platform Sutra of Huineng.

While the Patriarch was living in Bao Lin Monastery, the Grand Master Shen Xiu was preaching in Yu Quan Monastery of Jing Nan. At that time the two Schools, that of Hui Neng of the South and Shen Xiu of the North, flourished side by side. As the two Schools were distinguished from each other by the names "Sudden" (the South) and "Gradual" (the North), the question which sect they should follow baffled certain Buddhist scholars (of that time). (Seeing this), the Patriarch addressed the assembly as follows:
So far as the Dharma is concerned, there can be only one School. (If a distinction exists) it exists in the fact that the founder of one school is a northern man, while the other is a southerner. While there is only one dharma, some disciples realize it more quickly than others. The reason why the names 'Sudden' and 'Gradual' are given is that some disciples are superior to others in mental dispositions. So far as the Dharma is concerned, the distinction of 'Sudden' and 'Gradual' does not exist.

Rivalry between schools

While the socalled "Southern School" was said to place emphasis on sudden enlightenment, it also marked a shift in doctrinal basis from the Laṅkāvatāra Sūtra to the prajnaparamita tradition, especially the Diamond Sutra. The Laṅkāvatāra Sūtra, which endorses the Buddha-nature, emphasized purity of mind, which can be attained in gradations. The Diamond Sutra emphasizes śūnyatā, which "must be realized totally or not at all".

Once this dichotomy was in place, it defined its own logic and rhetorics, which are also recognizable in the distinction between Caodong (Sōtō) and Linji (Rinzai) schools. But it also leads to a "sometimes bitter and always prolix sectarian controversy between later Ch'an and Hua-yen exegetes". In the Huayan classification of teachings, the sudden approach was regarded inferior to the Perfect Teaching of Huayan. Guifeng Zongmi, fifth patriarch of Huayan and Chan master, devised his own classification to counter this subordination. To establish the superiority of Chan, Jinul, the most important figure in the formation of Korean Seon, explained the sudden approach as not pointing to mere emptiness, but to suchness or the dharmadhatu.

Later re-interpretations

Guifeng Zongmi, fifth-generation successor to Shenhui, also softened the edge between sudden and gradual. In his analysis, sudden awakening points to seeing into one's true nature, but is to be followed by a gradual cultivation to attain buddhahood.

This gradual cultivation is also recognized by Dongshan Liangjie, who described the Five Ranks of enlightenment. Other example of depiction of stages on the path are the Ten Bulls, which detail the steps on the Path, The Three Mysterious Gates of Linji, and the Four Ways of Knowing of Hakuin Ekaku. This gradual cultivation is described by Chan Master Sheng Yen as follows:

Ch'an expressions refer to enlightenment as "seeing your self-nature". But even this is not enough. After seeing your self-nature, you need to deepen your experience even further and bring it into maturation. You should have enlightenment experience again and again and support them with continuous practice. Even though Ch'an says that at the time of enlightenment, your outlook is the same as of the Buddha, you are not yet a full Buddha.

Hua-yen

In the Fivefold Classification of the Huayan school and the Five Periods and Eight Teachings of the Tiantai-school the sudden teaching was given a high place, but still inferior to the Complete or Perfect teachings of these schools.

Korean Seon

Chinul, a 12th-century Korean Seon master, followed Zongmi, and also emphasized that insight into our true nature is sudden, but is to be followed by practice to ripen the insight and attain full Buddhahood.

In contemporary Korean Seon, Seongcheol has defended the stance of "sudden insight, sudden cultivation". Citing Taego Bou (太古普愚: 1301-1382) as the true successor of the Linji Yixuan (臨済義玄) line of patriarchs rather than Jinul (知訥: 1158-1210), he advocated Hui Neng's original stance of 'sudden enlightenment, sudden cultivation' (Hangul: 돈오돈수, Hanja: 頓悟頓修) as opposed to Jinul's stance of 'sudden enlightenment, gradual cultivation' (Hangul: 돈오점수, Hanja: 頓悟漸修). Whereas Jinul had initially asserted that with enlightenment comes the need to further one's practice by gradually destroying the karmic vestiges attained through millions of rebirths, Huineng and Seongcheol maintained that with perfect enlightenment, all karmic remnants disappear and one becomes a Buddha immediately.

Popularisation in the west

When Zen was introduced in the west, the Rinzai stories of unconventional masters and sudden enlightenment caught the popular imagination. D. T. Suzuki was a seminal influence in this regard. It was Suzuki's contention that a Zen satori (awakening) was the goal of the tradition's training. As Suzuki portrayed it, Zen Buddhism was a highly practical religion whose emphasis on direct experience made it particularly comparable to forms of mystical experience that scholars such as William James had emphasized as the fountainhead of all religious sentiment.

Indian spirituality

The emphasis on direct experience is also recognized in forms of Indian spirituality, which gained popularity in the west in 1960s and 1970s, and further influenced the discourse on awakening in the west.

Ramana Maharshi - Akrama mukti

Ramana Maharshi made a distinction between akrama mukti, "sudden liberation", as opposed to the krama mukti, "gradual liberation" as in the Vedanta path of jnana yoga:

‘Some people,’ he said, ‘start off by studying literature in their youth. Then they indulge in the pleasures of the world until they are fed up with them. Next, when they are at an advanced age, they turn to books on Vedanta. They go to a guru and get initiated by him and then start the process of sravana, manana and nididhyasana, which finally culminates in samadhi. This is the normal and standard way of approaching liberation. It is called krama mukti [gradual liberation]. But I was overtaken by akrama mukti [sudden liberation] before I passed through any of the above-mentioned stages.’

Inchegeri Sampradaya - "the Ant's way"

The teachings of Bhausaheb Maharaj, the founder of the Inchegeri Sampradaya, have been called "the Ant's way",  the way of meditation, while the teachings of Siddharameshwar Maharaj and his disciples Nisargadatta Maharaj and Ranjit Maharaj have been called "the Bird's Way", the direct path to Self-discovery:

The way of meditation is a long arduous path while the Bird's Way is a clear direct path of Self investigation, Self exploration, and using thought or concepts as an aid to understanding and Self-Realization. Sometimes this approach is also called the Reverse Path. What Reverse Path indicates is the turning around of one's attention away from objectivity to the more subjective sense of one's Beingness. With the Bird's Way, first one's mind must be made subtle. This is generally done with some initial meditation on a mantra or phrase which helps the aspirant to step beyond the mental/conceptual body, using a concept to go beyond conceptualization.

The terms appear in the Varaha Upanishad, Chapter IV:

34. (The Rishi) Suka is a Mukta (emancipated person). (The Rishi) Vamadeva is a Mukta. There are no others (who have attained emancipation) than through these (viz., the two paths of these two Rishis). Those brave men who follow the path of Suka in this world become Sadyo-Muktas (viz., emancipated) immediately after (the body wear away);

35. While those who always follow the path of Vamadeva (i.e., Vedanta) in this world are subject again and again to rebirths and attain Krama (gradual) emancipation, through Yoga, Sankhya and Karmas associated with Sattva (Guna).

36. Thus there are two paths laid down by the Lord of Devas (viz.,) the Suka and Vamadeva paths. The Suka path is called the bird’s path; while the Vamadeva path is called the ant’s path.

 

Myelin

From Wikipedia, the free encyclopedia
 
Myelin
Neuron.svg
Structure of simplified neuron in the PNS
 
Neuron with oligodendrocyte and myelin sheath.svg
Neuron with oligodendrocyte and myelin sheath in the CNS
Details
SystemNervous system
Identifiers
FMA62977

Myelin is a lipid-rich (fatty) substance that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, each myelin sheath insulates the axon over a single long section and, in general, each axon comprises multiple long myelinated sections separated from each other by short myelin sheath-gaps called nodes of Ranvier.

Myelin is formed in the central nervous system (CNS; brain, spinal cord and optic nerve) by glial cells called oligodendrocytes and in the peripheral nervous system (PNS) by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from sensory organs such as the skin. Each myelin sheath is formed by the concentric wrapping of an oligodendrocyte (CNS) or Schwann cell (PNS) process (a limb-like extension from the cell body) around the axon. Myelin reduces the capacitance of the axonal membrane. On a molecular level, in the internodes it increases the distance between extracellular and intracellular ions, reducing the accumulation of charges. The discontinuous structure of the myelin sheath results in saltatory conduction, whereby the action potential "jumps" from one node of Ranvier, over a long myelinated stretch of the axon called the internode, before "recharging" at the next node of Ranvier, and so on, until it reaches the axon terminal. Nodes of Ranvier are the short (c. 1 micron) unmyelinated regions of the axon between adjacent long (c. 0.2 mm – >1 mm) myelinated internodes. Once it reaches the axon terminal, this electrical signal provokes the release of a chemical message or neurotransmitter that binds to receptors on the adjacent post-synaptic cell (e.g., nerve cell in the CNS or muscle cell in the PNS) at specialised regions called synapses.

This "insulating" role for myelin is essential for normal motor function (i.e. movement such as walking), sensory function (e.g. hearing, seeing or feeling the sensation of pain) and cognition (e.g. acquiring and recalling knowledge), as demonstrated by the consequences of disorders that affect it, such as the genetically determined leukodystrophies; the acquired inflammatory demyelinating disorder, multiple sclerosis; and the inflammatory demyelinating peripheral neuropathies. Due to its high prevalence, multiple sclerosis, which specifically affects the central nervous system (brain, spinal cord and optic nerve), is the best known disorder of myelin.

Development

The process of generating myelin is called myelination or myelinogenesis. In the CNS, cells called oligodendrocyte precursor cells (OPCs; the precursors of oligodendrocytes) differentiate into mature oligodendrocytes, which form myelin. In humans, myelination begins early in the 3rd trimester, although only little myelin is present in either the CNS or the PNS at the time of birth. During infancy, myelination progresses rapidly, with increasing numbers of axons acquiring myelin sheaths. This corresponds with the development of cognitive and motor skills, including language comprehension, speech acquisition, crawling and walking. Myelination continues through adolescence and early adulthood and although largely complete at this time, myelin sheaths can be added in grey matter regions such as the cerebral cortex, throughout life.

Species distribution

Myelin is considered a defining characteristic of the jawed vertebrates (gnathostomes), though axons are ensheathed by a type of cell, called glial cells, in invertebrates. These glial wraps are quite different from vertebrate compact myelin, formed, as indicated above, by concentric wrapping of the myelinating cell process multiple times around the axon. Myelin was first described in 1854 by Rudolf Virchow, although it was over a century later, following the development of electron microscopy, that its glial cell origin and its ultrastructure became apparent.

In vertebrates, not all axons are myelinated. For example, in the PNS, a large proportion of axons are unmyelinated. Instead, they are ensheathed by non-myelinating Schwann cells known as Remak SCs and arranged in Remak bundles. In the CNS, non-myelinated axons (or intermittently myelinated axons, meaning axons with long non-myelinated regions between myelinated segments) intermingle with myelinated ones and are entwined, at least partially, by the processes of another type of glial cell the astrocyte.

Composition

Transmission electron micrograph of a cross-section of a myelinated PNS axon, generated at the Electron Microscopy Facility at Trinity College, Hartford, Connecticut
Diagram of a myelinated axon in cross-section

CNS myelin differs slightly in composition and configuration from PNS myelin, but both perform the same "insulating" function (see above). Being rich in lipid, myelin appears white, hence the name given to the "white matter" of the CNS. Both CNS white matter tracts (e.g. the optic nerve, corticospinal tract and corpus callosum) and PNS nerves (e.g. the sciatic nerve and the auditory nerve, which also appear white) each comprise thousands to millions of axons, largely aligned in parallel. Blood vessels provide the route for oxygen and energy substrates such as glucose to reach these fibre tracts, which also contain other cell types including astrocytes and microglia in the CNS and macrophages in the PNS.

In terms of total mass, myelin comprises approximately 40% water; the dry mass comprises between 60% and 75% lipid and between 15% and 25% protein. Protein content includes myelin basic protein (MBP), which is abundant in the CNS where it plays a critical, non-redundant role in formation of compact myelin; myelin oligodendrocyte glycoprotein (MOG), which is specific to the CNS; and proteolipid protein (PLP), which is the most abundant protein in CNS myelin, but only a minor component of PNS myelin. In the PNS, myelin protein zero (MPZ or P0) has a similar role to that of PLP in the CNS in that it is involved in holding together the multiple concentric layers of glial cell membrane that constitute the myelin sheath. The primary lipid of myelin is a glycolipid called galactocerebroside. The intertwining hydrocarbon chains of sphingomyelin strengthen the myelin sheath. Cholesterol is an essential lipid component of myelin, without which myelin fails to form.

Function

Action potential propagation in myelinated neurons is faster than in unmyelinated neurons because of Saltatory conduction.

The main purpose of myelin is to increase the speed at which electrical impulses propagate along the myelinated fiber. In unmyelinated fibers, electrical impulses (action potentials) travel as continuous waves, but, in myelinated fibers, they "hop" or propagate by saltatory conduction. The latter is markedly faster than the former, at least for axons over a certain diameter. Myelin decreases capacitance and increases electrical resistance across the axonal membrane (the axolemma). It has been suggested that myelin permits larger body size by maintaining agile communication between distant body parts.

Myelinated fibers lack voltage-gated sodium channels along the myelinated internodes, exposing them only at the nodes of Ranvier. Here, they are highly abundant and densely packed. Positively charged sodium ions can enter the axon through these voltage-gated channels, leading to depolarisation of the membrane potential at the node of Ranvier. The resting membrane potential is then rapidly restored due to positively charged potassium ions leaving the axon through potassium channels. The sodium ions inside the axon then diffuse rapidly through the axoplasm (axonal cytoplasm), to the adjacent myelinated internode and ultimately to the next (distal) node of Ranvier, triggering the opening of the voltage gated sodium channels and entry of sodium ions at this site. Although the sodium ions diffuse through the axoplasm rapidly, diffusion is decremental by nature, thus nodes of Ranvier have to be (relatively) closely spaced, to secure action potential propagation. The action potential "recharges" at consecutive nodes of Ranvier as the axolemmal membrane potential depolarises to approximately +35 mV. Along the myelinated internode, energy-dependent sodium/potassium pumps pump the sodium ions back out of the axon and potassium ions back into the axon to restore the balance of ions between the intracellular (inside the cell, i.e. axon in this case) and extracellular (outwith the cell) fluids.

Whilst the role of myelin as an "axonal insulator" is well-established, other functions of myelinating cells are less well known or only recently established. The myelinating cell "sculpts" the underlying axon by promoting the phosphorylation of neurofilaments, thus increasing the diameter or thickness of the axon at the internodal regions; helps cluster molecules on the axolemma (such as voltage-gated sodium channels) at the node of Ranvier; and modulates the transport of cytoskeletal structures and organelles such as mitochondria, along the axon. In 2012, evidence came to light to support a role for the myelinating cell in "feeding" the axon. In other words, the myelinating cell seems to act as a local "fueling station" for the axon, which uses a great deal of energy to restore the normal balance of ions between it and its environment, following the generation of action potentials.

When a peripheral fiber is severed, the myelin sheath provides a track along which regrowth can occur. However, the myelin layer does not ensure a perfect regeneration of the nerve fiber. Some regenerated nerve fibers do not find the correct muscle fibers, and some damaged motor neurons of the peripheral nervous system die without regrowth. Damage to the myelin sheath and nerve fiber is often associated with increased functional insufficiency.

Unmyelinated fibers and myelinated axons of the mammalian central nervous system do not regenerate.

Clinical significance

Demyelination

Demyelination is the loss of the myelin sheath insulating the nerves, and is the hallmark of some neurodegenerative autoimmune diseases, including multiple sclerosis, acute disseminated encephalomyelitis, neuromyelitis optica, transverse myelitis, chronic inflammatory demyelinating polyneuropathy, Guillain–Barré syndrome, central pontine myelinosis, inherited demyelinating diseases such as leukodystrophy, and Charcot–Marie–Tooth disease. Sufferers of pernicious anaemia can also suffer nerve damage if the condition is not diagnosed quickly. Subacute combined degeneration of spinal cord secondary to pernicious anaemia can lead to slight peripheral nerve damage to severe damage to the central nervous system, affecting speech, balance, and cognitive awareness. When myelin degrades, conduction of signals along the nerve can be impaired or lost, and the nerve eventually withers. A more serious case of myelin deterioration is called Canavan disease.

The immune system may play a role in demyelination associated with such diseases, including inflammation causing demyelination by overproduction of cytokines via upregulation of tumor necrosis factor or interferon. MRI evidence that docosahexaenoic acid DHA ethyl ester improves myelination in generalized peroxisomal disorders https://n.neurology.org/content/51/1/26 .

Symptoms

Demyelination results in diverse symptoms determined by the functions of the affected neurons. It disrupts signals between the brain and other parts of the body; symptoms differ from patient to patient, and have different presentations upon clinical observation and in laboratory studies.

Typical symptoms include blurriness in the central visual field that affects only one eye, may be accompanied by pain upon eye movement, double vision, loss of vision/hearing, odd sensation in legs, arms, chest, or face, such as tingling or numbness (neuropathy), weakness of arms or legs, cognitive disruption, including speech impairment and memory loss, heat sensitivity (symptoms worsen or reappear upon exposure to heat, such as a hot shower), loss of dexterity, difficulty coordinating movement or balance disorder, difficulty controlling bowel movements or urination, fatigue, and tinnitus.

Myelin repair

Research to repair damaged myelin sheaths is ongoing. Techniques include surgically implanting oligodendrocyte precursor cells in the central nervous system and inducing myelin repair with certain antibodies. While results in mice have been encouraging (via stem cell transplantation), whether this technique can be effective in replacing myelin loss in humans is still unknown. Cholinergic treatments, such as acetylcholinesterase inhibitors (AChEIs), may have beneficial effects on myelination, myelin repair, and myelin integrity. Increasing cholinergic stimulation also may act through subtle trophic effects on brain developmental processes and particularly on oligodendrocytes and the lifelong myelination process they support. Increasing oligodendrocyte cholinergic stimulation, AChEIs, and other cholinergic treatments, such as nicotine, possibly could promote myelination during development and myelin repair in older age. Glycogen synthase kinase 3β inhibitors such as lithium chloride have been found to promote myelination in mice with damaged facial nerves. Cholesterol is a necessary nutrient for the myelin sheath, along with vitamin B12.

Dysmyelination

Dysmyelination is characterized by a defective structure and function of myelin sheaths; unlike demyelination, it does not produce lesions. Such defective sheaths often arise from genetic mutations affecting the biosynthesis and formation of myelin. The shiverer mouse represents one animal model of dysmyelination. Human diseases where dysmyelination has been implicated include leukodystrophies (Pelizaeus–Merzbacher disease, Canavan disease, phenylketonuria) and schizophrenia.

Invertebrate myelin

Functionally equivalent myelin-like sheaths are found in several invertebrate taxa including oligochaetes, penaeids, palaemonids, and calanoids. These myelin-like sheaths share several structural features with the sheaths found in vertebrates including multiplicity of membranes, condensation of membrane, and nodes. However, the nodes in vertebrates are annular; i.e. they encircle the axon. In contrast, nodes found in the sheaths of invertebrates are either annular or fenestrated; i.e. they are restricted to "spots". It is notable that the fastest recorded conduction speed (across both vertebrates and invertebrates) is found in the ensheathed axons of the Kuruma shrimp, an invertebrate, ranging between 90 and 200 m/s (cf. 100–120 m/s for the fastest myelinated vertebrate axon).

Grey matter

From Wikipedia, the free encyclopedia
 
Grey matter
Spinal nerve.svg
The formation of the spinal nerve from the dorsal and ventral roots (with grey matter labelled at centre right).
 
Grey matter and white matter - very high mag.jpg
Micrograph showing grey matter, with the characteristic neuronal cell bodies (dark shade of pink), and white matter with its characteristic fine meshwork-like appearance (left of image; lighter shade of pink). HPS stain.
Details
Identifiers
LatinSubstantia grisea
MeSHD066128
TA98A14.1.00.002
A14.1.02.020
A14.1.04.201
A14.1.05.201
A14.1.05.401
A14.1.06.301
TA25365
FMA67242

Grey matter (or gray matter) is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and unmyelinated axons), glial cells (astrocytes and oligodendrocytes), synapses, and capillaries. Grey matter is distinguished from white matter in that it contains numerous cell bodies and relatively few myelinated axons, while white matter contains relatively few cell bodies and is composed chiefly of long-range myelinated axons. The colour difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies.

Structure

Grey matter refers to unmyelinated neurons and other cells of the central nervous system. It is present in the brain, brainstem and cerebellum, and present throughout the spinal cord.

Grey matter is distributed at the surface of the cerebral hemispheres (cerebral cortex) and of the cerebellum (cerebellar cortex), as well as in the depths of the cerebrum (thalamus; hypothalamus; subthalamus, basal gangliaputamen, globus pallidus, nucleus accumbens; septal nuclei), cerebellar (deep cerebellar nuclei – dentate nucleus, globose nucleus, emboliform nucleus, fastigial nucleus), brainstem (substantia nigra, red nucleus, olivary nuclei, cranial nerve nuclei).

Grey matter in the spinal cord is known as the grey column which travels down the spinal cord distributed in three grey columns that are presented in an "H" shape. The forward-facing column is the anterior grey column, the rear-facing one is the posterior grey column and the interlinking one is the lateral grey column. The grey matter on the left and right side is connected by the grey commissure. The grey matter in the spinal cord consists of interneurons, as well as the cell bodies of projection neurons.

Grey matter undergoes development and growth throughout childhood and adolescence. Recent studies using cross-sectional neuroimaging have shown that by around the age of 8 the volume of grey matter begins to decrease. However, the density of grey matter appears to increase as a child develops into early adulthood. Males tend to exhibit grey matter of increased volume but lower density than that of females.

Function

Grey matter contains most of the brain's neuronal cell bodies. The grey matter includes regions of the brain involved in muscle control, and sensory perception such as seeing and hearing, memory, emotions, speech, decision making, and self-control.

The grey matter in the spinal cord is split into three grey columns:

The grey matter of the spinal cord can be divided into different layers, called Rexed laminae. These describe, in general, the purpose of the cells within the grey matter of the spinal cord at a particular location.

Clinical significance

High alcohol consumption has been correlated with significant reductions in grey matter volume. Short-term cannabis use (30 days) is not correlated with changes in white or grey matter. However, several cross-sectional studies have shown that repeated long-term cannabis use is associated with smaller grey matter volumes in the hippocampus, amygdala, medial temporal cortex, and prefrontal cortex, with increased grey matter volume in the cerebellum. Long-term cannabis use is also associated with alterations in white matter integrity in an age-dependent manner, with heavy cannabis use during adolescence and early adulthood associated with the greatest amount of change.

Meditation has been shown to change grey matter structure.

Habitual playing of action video games has been reported to promote a reduction of grey matter in the hippocampus while 3D platformer games have been reported to increase grey matter in the hippocampus.

Women and men with equivalent IQ scores have differing proportions of grey to white matter in cortical brain regions associated with intelligence.

Pregnancy renders substantial changes in brain structure, primarily reductions in grey matter volume in regions subserving social cognition. The grey matter reductions endured for at least 2 years post-pregnancy. The profile of brain changes is comparable to that taking place during adolescence, a hormonally similar transitional period of life.

History

Etymology

In the current edition of the official Latin nomenclature, Terminologia Anatomica, substantia grisea is used for English grey matter. The adjective grisea for grey is however not attested in classical Latin. The adjective grisea is derived from the French word for grey, gris. Alternative designations like substantia cana and substantia cinerea are being used alternatively. The adjective cana, attested in classical Latin, can mean grey, or greyish white. The classical Latin cinerea means ash-coloured.

Additional images

 

Sunday, August 22, 2021

White matter

From Wikipedia, the free encyclopedia
 
White matter
Grey matter and white matter - very high mag.jpg
 
Micrograph showing white matter with its characteristic fine meshwork-like appearance (left of image - lighter shade of pink) and grey matter, with the characteristic neuronal cell bodies (right of image - dark shade of pink). HPS stain.
 
Human brain right dissected lateral view description.JPG
 
Human brain right dissected lateral view, showing grey matter (the darker outer parts), and white matter (the inner and prominently whiter parts).
Details
LocationCentral nervous system
Identifiers
Latinsubstantia alba
MeSHD066127
TA98A14.1.00.009
A14.1.02.024
A14.1.02.201
A14.1.04.101
A14.1.05.102
A14.1.05.302
A14.1.06.201
TA25366
FMA83929

White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution of action potentials, acting as a relay and coordinating communication between different brain regions.

White matter is named for its relatively light appearance resulting from the lipid content of myelin. However, the tissue of the freshly cut brain appears pinkish-white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color in prepared specimens is due to its usual preservation in formaldehyde.

Structure

White matter

White matter is composed of bundles, which connect various grey matter areas (the locations of nerve cell bodies) of the brain to each other, and carry nerve impulses between neurons. Myelin acts as an insulator, which allows electrical signals to jump, rather than coursing through the axon, increasing the speed of transmission of all nerve signals.

The total number of long range fibers within a cerebral hemisphere is 2% of the total number of cortico-cortical fibers (across cortical areas) and is roughly the same number as those that communicate between the two hemispheres in the brain's largest white tissue structure, the corpus callosum. Schüz and Braitenberg note "As a rough rule, the number of fibres of a certain range of lengths is inversely proportional to their length."

White matter in nonelderly adults is 1.7–3.6% blood.

Grey matter

The other main component of the brain is grey matter (actually pinkish tan due to blood capillaries), which is composed of neurons. The substantia nigra is a third colored component found in the brain that appears darker due to higher levels of melanin in dopaminergic neurons than its nearby areas. Note that white matter can sometimes appear darker than grey matter on a microscope slide because of the type of stain used. Cerebral- and spinal white matter do not contain dendrites, neural cell bodies, or shorter axons, which can only be found in grey matter.

Location

White matter forms the bulk of the deep parts of the brain and the superficial parts of the spinal cord. Aggregates of grey matter such as the basal ganglia (caudate nucleus, putamen, globus pallidus, substantia nigra, subthalamic nucleus, nucleus accumbens) and brainstem nuclei (red nucleus, cranial nerve nuclei) are spread within the cerebral white matter.

The cerebellum is structured in a similar manner as the cerebrum, with a superficial mantle of cerebellar cortex, deep cerebellar white matter (called the "arbor vitae") and aggregates of grey matter surrounded by deep cerebellar white matter (dentate nucleus, globose nucleus, emboliform nucleus, and fastigial nucleus). The fluid-filled cerebral ventricles (lateral ventricles, third ventricle, cerebral aqueduct, fourth ventricle) are also located deep within the cerebral white matter.

Myelinated axon length

Men have more white matter than women both in volume and in length of myelinated axons. At the age of 20, the total length of myelinated fibers in men is 176,000 km while that of a woman is 149,000 km. There is a decline in total length with age of about 10% each decade such that a man at 80 years of age has 97,200 km and a female 82,000 km. Most of this reduction is due to the loss of thinner fibers.

Function

White matter is the tissue through which messages pass between different areas of grey matter within the central nervous system. The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin is found in almost all long nerve fibers, and acts as an electrical insulation. This is important because it allows the messages to pass quickly from place to place.

Unlike grey matter, which peaks in development in a person's twenties, the white matter continues to develop, and peaks in middle age.

Research

Multiple sclerosis (MS) is the most common of the inflammatory demyelinating diseases of the central nervous system which affect white matter. In MS lesions, the myelin sheath around the axons is deteriorated by inflammation. Alcohol use disorders are associated with a decrease in white matter volume.

Amyloid plaques in white matter may be associated with Alzheimer's disease and other neurodegenerative diseases. Other changes that commonly occur with age include the development of leukoaraiosis, which is a rarefaction of the white matter that can be correlated with a variety of conditions, including loss of myelin pallor, axonal loss, and diminished restrictive function of the blood–brain barrier.

White matter lesions on magnetic resonance imaging are linked to several adverse outcomes, such as cognitive impairment and depression. White matter hyperintensity are more than often present with vascular dementia, particularly among small vessel/subcortical subtypes of vascular dementia.

Volume

Smaller volumes (in terms of group averages) of white matter might be associated with larger deficits in attention, declarative memory, executive functions, intelligence, and academic achievement. However, volume change is continuous throughout one's lifetime due to neuroplasticity, and is a contributing factor rather than determinant factor of certain functional deficits due to compensating effects in other brain regions. The integrity of white matter declines due to aging. Nonetheless, regular aerobic exercise appears to either postpone the aging effect or in turn enhance the white matter integrity in the long run. Changes in white matter volume due to inflammation or injury may be a factor in the severity of obstructive sleep apnea.

Imaging

The study of white matter has been advanced with the neuroimaging technique called diffusion tensor imaging where magnetic resonance imaging (MRI) brain scanners are used. As of 2007, more than 700 publications have been published on the subject.

A 2009 paper by Jan Scholz and colleagues used diffusion tensor imaging (DTI) to demonstrate changes in white matter volume as a result of learning a new motor task (e.g. juggling). The study is important as the first paper to correlate motor learning with white matter changes. Previously, many researchers had considered this type of learning to be exclusively mediated by dendrites, which are not present in white matter. The authors suggest that electrical activity in axons may regulate myelination in axons. Or, gross changes in the diameter or packing density of the axon might cause the change. A more recent DTI study by Sampaio-Baptista and colleagues reported changes in white matter with motor learning along with increases in myelination.

 

Magnet school

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