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Antigua and Barbuda Antigua and Barbuda is a sovereign archipelagic country composed of Antigua, Barbuda, and numerous other small islands. Antigua and Barbuda has a total area of 440 km2 (170 sq mi), making it one of the smallest countries in the Caribbean. The country is mostly flat, with the highest points on Antigu...
Hunter-gatherers settled the islands starting around 3000 BC, likely arriving on canoes from Central and South America. They were followed by the Arawaks of Venezuela during the Ceramic Period. In 1493, Christopher Columbus surveyed the island of Antigua, which resulted in an attempt at Spanish settlement in 1520. Anti...
Antigua and Barbuda is a high-income country. It is a member of the United Nations, the OECS, the Regional Security System, CARICOM, and the World Trade Organisation. Antigua and Barbuda is one of the only countries in the Caribbean to maintain an air force, and has a mostly service-based economy. Antigua and Barbuda m...
History. Pre-colonial period. Antigua was first settled by archaic age Indigenous hunter-gatherers called the Ciboney. Carbon dating has established the earliest settlements started around 3100 BC. They were succeeded by the ceramic age pre-Columbian Arawak-speaking Saladoid people who migrated from the lower Orinoco R...
Colonial era. The English maintained control of the islands, repulsing an attempted French attack in 1666. The brutal conditions endured by the slaves led to revolts in 1701 and 1729 and a planned revolt in 1736, the last led by Prince Klaas, though it was discovered before it began and the ringleaders were executed. S...
Independence era. The first two decades of Antigua's independence were dominated politically by the Bird family and the ABLP, with Vere Bird ruling from 1981 to 1994, followed by his son Lester Bird from 1994 to 2004. Though providing a degree of political stability, and boosting tourism to the country, the Bird govern...
In 2016, Nelson's Dockyard was designated as a UNESCO World Heritage Site. Most of Barbuda was devastated in early September 2017 by Hurricane Irma, which brought winds with speeds reaching 295 km/h (185 mph). The storm damaged or destroyed 95% of the island's buildings and infrastructure, leaving Barbuda "barely habit...
Both of these islands have very irregularly shaped coastlines that are dotted with beaches, lagoons, and natural harbours. There are reefs and shoals that surround the islands on all sides. Because of the low amount of rainfall, there are not many streams. On neither of these islands can sufficient quantities of fresh ...
Hurricanes are common, including the powerful Category 5 Hurricane Irma, on 6 September 2017, which damaged 95% of the structures on Barbuda. Some 1,800 people were evacuated to Antigua. Officials quoted by "Time" indicated that over $100 million would be required to rebuild homes and infrastructure. Philmore Mullin, D...
Antigua and Barbuda's population density of 211 people per square kilometre is considerably low for the region, with Barbuda being among the least densely populated islands in the Caribbean. Antigua and Barbuda is one of the least urbanized countries in the world, with only 24% of the country inhabiting an urban area i...
By proportion, Antigua and Barbuda has the highest foreign-born population in the Americas, with immigrants making up 30% of the population in 2011. Due to this high immigrant population, people among the African descendant population tend to identify with place of origin rather than with their ethnicity. The largest i...
Religion. A majority (77%) of Antiguans are Christians, with the Anglicans (17.6%) being the largest single denomination. Other Christian denominations present are Seventh-day Adventist Church (12.4%), Pentecostalism (12.2%), Moravian Church (8.3%), Roman Catholics (8.2%), Methodist Church (5.6%), Wesleyan Holiness Chu...
The legislative power of Antigua and Barbuda is vested in Parliament, which is composed of the Monarch, the Senate, and the House of Representatives. The Senate is composed of seventeen members, who are appointed by the Governor-General. Ten of the members are appointed on the advice of the Prime Minister, these member...
The judiciary of Antigua and Barbuda is composed of the magistrates' courts, the Supreme Court including the High Court and the Court of Appeal, and the Judicial Committee of the Privy Council, the country's final court. Antiguan and Barbudan voters rejected a proposal to make the Caribbean Court of Justice the final c...
Administrative divisions. Antigua and Barbuda is composed of six parishes and two dependencies. Saint John is the most populous parish, home to well over half of Antigua and Barbuda's population. During colonial times, the parishes were governed by parish vestries, however, the parishes now lack any sort of government....
Foreign relations. The Minister of Foreign Affairs, Trade and Barbuda Affairs is responsible for overseeing the foreign relations of Antigua and Barbuda. The current minister is Paul Chet Greene. Antigua and Barbuda is a founding member of the Organisation of Eastern Caribbean States, as well as a member of the United ...
Defence and national security. The Minister of Finance, Corporate Governance and Public Private Partnerships is responsible for the Antigua and Barbuda Defence Force, the country's military. The Minister of Legal Affairs, Public Safety, Immigration and Labour is responsible for the national security of Antigua and Barb...
Human rights. Violations of human rights in Antigua and Barbuda have been increasingly reported since 2017. In particular, a land crisis caused by Hurricane Irma has resulted in a deterioration of the relationship between the two main islands, with the central government repeatedly threatening to abolish the communal l...
Economy. Tourism dominates the economy, accounting for more than half of the gross domestic product (GDP). As a destination for the most affluent travelers, Antigua is well known for its extensive collection of five-star resorts. However, weaker tourist activity in lower and middle market segments since the beginning o...
The nation, which consists of two islands, directs the majority of its agricultural production toward the markets that are found within the nation. This is done despite the fact that the nation has a limited water supply and a shortage of laborers as a result of the higher wages offered in the tourism and construction ...
The Citizenship by Investment Unit (CIU) is the government authority responsible for processing all applications for Agent's Licenses as well as all applications for Citizenship by Investment made by applicants and their family members. This unit was established by the Prime Minister and is known as the Citizenship by ...
Benna has long been eclipsed by Calypso and increasingly Soca, which includes South Asian rhythms. The art of Antigua and Barbuda began with the Arawak people. Their artwork included pictographs and petroglyphs. These geometric shapes, animals, and plant artworks are said to have been used for ceremonial or religious p...
Antigua and Barbuda has eleven public holidays. On the advice of the Cabinet, the Governor-General may also proclaim other holidays. Historically, about three weeks before Christmas Day, carol singers would roam the various villages, carrying carol trees and lanterns. "John Bulls" are replicas of "masked African witch ...
An important part of the Antiguan and Barbudan breakfast is Antigua Sunday bread. It is sold in many bakeries on both islands, and instead of being made with butter, it is made with lard. There are often decorative twists on the crust of the bread. Antiguan raisin buns, often called "bun and cheese", is another traditi...
Azincourt Azincourt ( ; ) is a commune in the Pas-de-Calais department in northern France. It is situated north-west of Saint-Pol-sur-Ternoise on the D71 road between Hesdin and Fruges. The Late Medieval Battle of Agincourt between the English and the French took place in the commune in 1415. Toponym. The name is atte...
After he became king in 1509, Henry VIII is purported to have commissioned an English translation of a Life of Henry V so that he could emulate him, on the grounds that he thought that launching a campaign against France would help him to impose himself on the European stage. In 1513, Henry VIII crossed the English Cha...
Since 2004 a large medieval festival organised by the local community, the CHM, The Azincourt Alliance, and various other UK societies commemorating the battle, local history and medieval life, arts and crafts has been held in the village. Prior to this date the festival was held in October, but due to the inclement we...
Albert Speer Berthold Konrad Hermann Albert Speer (; ; 19 March 1905 – 1 September 1981) was a German architect who served as Minister of Armaments and War Production in Nazi Germany during most of World War II. A close ally of Adolf Hitler, he was convicted at the Nuremberg trials and sentenced to 20 years in prison. ...
After the war, Speer was among the 24 "major war criminals" charged by the International Military Tribunal for Nazi atrocities. He was found guilty of war crimes and crimes against humanity, principally for the use of slave labor, narrowly avoiding a death sentence. Having served his full term, Speer was released in 19...
Early years and personal life. Speer was born in Mannheim, into an upper-middle-class family. He was the second of three sons of Luise Máthilde Wilhelmine (Hommel) and Albert Friedrich Speer. In 1918, the family leased their Mannheim residence and moved to a home they had in Heidelberg. Henry T. King, deputy prosecutor...
In mid-1922, Speer began courting Margarete (Margret) Weber (1905–1987), the daughter of a successful craftsman who employed 50 workers. The relationship was frowned upon by Speer's class-conscious mother, who felt the Webers were socially inferior. Despite this opposition, the two married in Berlin on 28 August 1928; ...
The organizers of the 1933 Nuremberg Rally asked Speer to submit designs for the rally, bringing him into contact with Hitler for the first time. Neither the organizers nor Rudolf Hess were willing to decide whether to approve the plans, and Hess sent Speer to Hitler's Munich apartment to seek his approval. This work w...
In the English version of his memoirs, Speer says that his political commitment merely consisted of paying his "monthly dues". He assumed his German readers would not be so gullible and told them the Nazi Party offered a "new mission". He was more forthright in an interview with William Hamsher in which he said he join...
One of Speer's first commissions after Troost's death was the "Zeppelinfeld" stadium in Nuremberg. It was used for Nazi propaganda rallies and can be seen in Leni Riefenstahl's propaganda film "Triumph of the Will". The building was able to hold 340,000 people. Speer insisted that as many events as possible be held at ...
Plans to build a new Reich Chancellery had been underway since 1934. Land had been purchased by the end of 1934 and starting in March 1936 the first buildings were demolished to create space at Voßstraße. Speer was involved virtually from the beginning. In the aftermath of the Night of the Long Knives, he had been comm...
During the Chancellery project, the pogrom of "Kristallnacht" took place. Speer made no mention of it in the first draft of "Inside the Third Reich". It was only on the urgent advice of his publisher that he added a mention of seeing the ruins of the Central Synagogue in Berlin from his car. "Kristallnacht" accelerated...
As Germany started World War II in Europe, Speer instituted quick-reaction squads to construct roads or clear away debris; before long, these units would be used to clear bomb sites. Speer used forced Jewish labor on these projects, in addition to regular German workers. Construction stopped on the Berlin and Nüremberg...
Speer was fêted at the time, and in the post-war era, for performing an "armaments miracle" in which German war production dramatically increased. This miracle was brought to a halt in the summer of 1943 by, among other factors, the first sustained Allied bombing. Other factors probably contributed to the increase more...
As Minister of Armaments, Speer was responsible for supplying weapons to the army. With Hitler's full agreement, he decided to prioritize tank production, and he was given unrivaled power to ensure success. Hitler was closely involved with the design of the tanks, but kept changing his mind about the specifications. Th...
Speer realized that with six million workers drafted into the armed forces, there was a labor shortage in the war economy, and not enough workers for his factories. In response, Hitler appointed Fritz Sauckel as a "manpower dictator" to obtain new workers. Speer and Sauckel cooperated closely to meet Speer's labor dema...
Consolidation of arms production. Following his appointment as Minister of Armaments, Speer was in control of armaments production solely for the Army. He coveted control of the production of armaments for the "Luftwaffe" and "Kriegsmarine" as well. He set about extending his power and influence with unexpected ambitio...
In December 1943, Speer visited Organisation Todt workers in Lapland, where he seriously damaged his knee and was incapacitated for several months. He was under the dubious care of Professor Karl Gebhardt at a medical clinic called Hohenlychen where patients "mysteriously failed to survive". In mid-January 1944, Speer ...
The Fighter Staff committee was instrumental in bringing about the increased exploitation of slave labor in the war economy. The SS provided 64,000 prisoners for 20 separate projects from various concentration camps including Mittelbau-Dora. Prisoners worked for Junkers, Messerschmitt, Henschel and , among others. To i...
On 14 April 1944, Speer lost control of Organisation Todt to his deputy, Franz Xaver Dorsch. He opposed the assassination attempt against Hitler on 20 July 1944. He was not involved in the plot, and played a minor role in the regime's efforts to regain control over Berlin after Hitler survived. After the plot Speer's r...
By mid-March, Speer had accepted that Germany's economy would collapse within the next eight weeks. While he sought to frustrate directives to destroy industrial facilities in areas at risk of capture, so that they could be used after the war, he still supported the war's continuation. Speer provided Hitler with a memo...
By April, little was left of the armaments industry, and Speer had few official duties. Speer visited the "Führerbunker" on 22 April for the last time. He met Hitler and toured the damaged Chancellery before leaving Berlin to return to Hamburg. Speer would later claim in his memoirs that during this visit he "confessed...
Post-war. Nuremberg trial. Speer was taken to several internment centres for Nazi officials and interrogated. In September 1945, he was told that he would be tried for war crimes, and several days later, he was moved to Nuremberg and incarcerated there. Speer was indicted on four counts: participating in a common plan ...
Imprisonment. On 18 July 1947, Speer was transferred to Spandau Prison in Berlin to serve his prison term. There he was known as Prisoner Number Five. Speer's parents died while he was incarcerated. His father, who died in 1947, despised the Nazis and was silent upon meeting Hitler. His mother died in 1952. As a Nazi P...
The prisoners were forbidden to write memoirs. Speer was able to have his writings sent to Wolters, however, and they eventually amounted to 20,000 pages. He had completed his memoirs by November 1953, and they became the basis of "Inside the Third Reich". In "Spandau Diaries", Speer aimed to present himself as a tragi...
Speer's supporters maintained calls for his release. Among those who pledged support for his sentence to be commuted were Charles de Gaulle and US diplomat George Wildman Ball. Willy Brandt was an advocate of his release, putting an end to the de-Nazification proceedings against him, which could have caused his propert...
He said little, reserving most comments for a major interview published in "Der Spiegel" in November 1966. Although he stated he hoped to resume an architectural career, his sole project, a collaboration for a brewery, was unsuccessful. Instead, he revised his Spandau writings into two autobiographical books, "Inside t...
He found himself unable to re-establish a relationship with his children, even with his son Albert, who had also become an architect. According to Speer's daughter Hilde Schramm, "One by one, my sister and brothers gave up. There was no communication." He provided financial support for his brother Hermann after the war...
Speer's memoirs were a phenomenal success. The public was fascinated by an inside view of the Third Reich and a major war criminal became a popular figure almost overnight. Importantly, he provided an alibi to older Germans who had been Nazis. If Speer, who had been so close to Hitler, had not known the full extent of ...
He had remained married to his wife, but he had formed a relationship with a German woman living in London and was with her at the time of his death. His daughter, Margret Nissen, wrote in her 2005 memoirs that after his release from Spandau he spent all of his time constructing the "Speer Myth". The Speer myth. The Go...
Speer had carefully constructed an image of himself as an apolitical technocrat who deeply regretted having failed to discover the monstrous crimes of the Third Reich. This construction was accepted almost at face value by historian Hugh Trevor-Roper when investigating the death of Adolf Hitler for British Intelligence...
After Speer's death, Matthias Schmidt published a book that demonstrated that Speer had ordered the eviction of Jews from their Berlin homes. By 1999, historians had amply demonstrated that Speer had lied extensively. Even so, public perceptions of Speer did not change substantially until Heinrich Breloer aired the bio...
The image of the "good Nazi" was supported by numerous Speer myths. In addition to the myth that he was an apolitical technocrat, he claimed he did not have full knowledge of the Holocaust or the persecution of the Jews. Another myth posits that Speer revolutionized the German war machine after his appointment as Minis...
Speer also sought to portray himself as an opponent of Hitler's leadership. Despite his opposition to the 20 July plot, he falsely claimed in his memoirs to have been sympathetic to the plotters. He maintained Hitler was cool towards him for the remainder of his life after learning they had included him on a list of po...
Speer did not deny being present at the Posen speeches to Nazi leaders at a conference in Posen (Poznań) on 6 October 1943, but claimed to have left the auditorium before Himmler said during his speech: "The grave decision had to be taken to cause this people to vanish from the earth", and later, "The Jews must be exte...
The armaments "miracle" was a myth; Speer had used statistical manipulation to support his claims. The production of armaments did rise; however, this was due to the normal causes of reorganization before Speer came to office, the relentless mobilization of slave labor and a deliberate reduction in the quality of outpu...
During the war, the Speer-designed New Reich Chancellery was largely destroyed by air raids and in the Battle of Berlin. The exterior walls survived, but they were eventually dismantled by the Soviets. Unsubstantiated rumors have claimed that the remains were used for other building projects such as the Humboldt Univer...
Asteraceae Asteraceae () is a large family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the order Asterales. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is...
The oldest known fossils are pollen grains from the Late Cretaceous (Campanian to Maastrichtian) of Antarctica, dated to million years ago (mya). It is estimated that the crown group of Asteraceae evolved at least 85.9 mya (Late Cretaceous, Santonian) with a stem node age of 88–89 mya (Late Cretaceous, Coniacian). Aste...
Stems. The stems are herbaceous, aerial, branched, and cylindrical with glandular hairs, usually erect, but can be prostrate to ascending. The stems can contain secretory canals with resin, or latex, which is particularly common among the Cichorioideae. Leaves. Leaves can be alternate, opposite, or whorled. They may be...
Floral heads. In plants of the Asteraceae, what appears to be a single "daisy"-type flower is actually a composite of several much smaller flowers, known as the "capitulum" or "head". By visually presenting as a single flower, the capitulum functions in attracting pollinators, in the same manner that other "showy" flow...
Nearest to the flower stem lie a series of small, usually green, scale-like bracts. These are known as "phyllaries"; collectively, they form the involucre, which serves to protect the immature head of florets during its development. The individual florets are arranged atop a dome-like structure called the "receptacle"....
A "ligulate flower" is a five-lobed, strap-shaped, individual flower found in the heads of certain other asteraceous species. A "ligule" is the strap-shaped tongue of the corolla of either a ray flower or of a ligulate flower. A "disk flower" (or "disc flower") is a radially symmetric individual flower in the head, whi...
Floral structures. The distinguishing characteristic of Asteraceae is their inflorescence, a type of specialised, composite flower head or "pseudanthium", technically called a calathium or "capitulum", that may look superficially like a single flower. The "capitulum" is a contracted raceme composed of numerous individu...
The florets have five petals fused at the base to form a corolla tube and they may be either actinomorphic or zygomorphic. "Disc florets" are usually actinomorphic, with five petal lips on the rim of the corolla tube. The petal lips may be either very short, or long, in which case they form deeply lobed petals. The lat...
The calyx of the florets may be absent, but when present is always modified into a pappus of two or more teeth, scales or bristles and this is often involved in the dispersion of the seeds. As with the bracts, the nature of the pappus is an important diagnostic feature. There are usually four or five stamens. The filam...
Pollen. The pollen of composites is typically echinolophate, a morphological term meaning "with elaborate systems of ridges and spines dispersed around and between the apertures." Metabolites. In Asteraceae, the energy store is generally in the form of inulin rather than starch. They produce iso/chlorogenic acid, sesqu...
Phylogeny. The phylogenetic tree of subfamilies presented below is based on Panero & Funk (2002) updated in 2014, and now also includes the monotypic Famatinanthoideae. The diamond (♦) denotes a very poorly supported node (<50% bootstrap support), the dot (•) a poorly supported node (<80%). The family include...
The oldest known fossils of members of Asteraceae are pollen grains from the Late Cretaceous of Antarctica, dated to ~76–66 mya (Campanian to Maastrichtian) and assigned to the extant genus "Dasyphyllum". Barreda, "et al." (2015) estimated that the crown group of Asteraceae evolved at least 85.9 mya (Late Cretaceous, S...
The alternative (as it came later) name Asteraceae () comes to international scientific vocabulary from Neo-Latin, from "Aster", the type genus, + "-aceae", a standardized suffix for plant family names in modern taxonomy. This genus name comes from the Classical Latin word , "star", which came from Ancient Greek (), "s...
Ecology. Asteraceae are especially common in open and dry environments. Many members of Asteraceae are pollinated by insects, which explains their value in attracting beneficial insects, but anemophily is also present (e.g. "Ambrosia", "Artemisia"). There are many apomictic species in the family. Seeds are ordinarily d...
Uses. Asteraceae is an economically important family, providing products such as cooking oils, leaf vegetables like lettuce, sunflower seeds, artichokes, sweetening agents, coffee substitutes and herbal teas. Several genera are of horticultural importance, including pot marigold ("Calendula officinalis"), "Echinacea" (...
Many members of the family are grown as ornamental plants for their flowers, and some are important ornamental crops for the cut flower industry. Some examples are "Chrysanthemum", "Gerbera", "Calendula", "Dendranthema", "Argyranthemum", "Dahlia", "Tagetes", "Zinnia", and many others. Many species of this family posses...
Apiaceae Apiaceae () or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus "Apium," and commonly known as the celery, carrot, or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plants, with more than 3,800 species in about 446 genera, including s...
The defining characteristic of this family is the inflorescence, the flowers nearly always aggregated in terminal umbels, that may be simple or more commonly compound, often umbelliform cymes. The flowers are usually perfect (hermaphroditic), and actinomorphic, but there may be zygomorphic flowers at the edge of the um...
Taxonomy. Apiaceae was first described by John Lindley in 1836. The name is derived from the type genus "Apium", which was originally used by Pliny the Elder circa 50 AD for a celery-like plant. The alternative name for the family, Umbelliferae, derives from the inflorescence being generally in the form of a compound u...
Classification and phylogeny. Prior to molecular phylogenetic studies, the family was subdivided primarily based on fruit characteristics. Molecular phylogenetic analyses from the mid-1990s onwards have shown that fruit characters evolved in parallel many times, so that using them in classification resulted in units th...
The subfamilies can be further divided into tribes and clades, with many clades falling outside formally recognized tribes. Genera. The number of genera accepted by sources varies. , Plants of the World Online (PoWO) accepted 444 genera, while GRIN Taxonomy accepted 462. The PoWO genera are not a subset of those in GRI...
Other notable cultivated Apiaceae include chervil ("Anthriscus cerefolium"), angelica ("Angelica" spp.), celery ("Apium graveolens"), arracacha ("Arracacia xanthorrhiza"), sea holly ("Eryngium" spp.), asafoetida ("Ferula asafoetida"), galbanum ("Ferula gummosa"), cicely ("Myrrhis odorata"), anise ("Pimpinella anisum"),...
Other uses. The poisonous members of the Apiaceae have been used for a variety of purposes globally. The poisonous "Oenanthe crocata" has been used as an aid in suicides, and arrow poisons have been made from various other family species. "Daucus carota" has been used as coloring for butter. "Dorema ammoniacum", "Ferul...
Axon An axon (from Greek ἄξων "áxōn", axis) or nerve fiber (or nerve fibre: see spelling differences) is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit in...
An axon is one of two types of cytoplasmic protrusions from the cell body of a neuron; the other type is a dendrite. Axons are distinguished from dendrites by several features, including shape (dendrites often taper while axons usually maintain a constant radius), length (dendrites are restricted to a small region arou...
A single axon, with all its branches taken together, can target multiple parts of the brain and generate thousands of synaptic terminals. A bundle of axons make a nerve tract in the central nervous system, and a fascicle in the peripheral nervous system. In placental mammals the largest white matter tract in the brain ...
There are two types of axons in the nervous system: myelinated and unmyelinated axons. Myelin is a layer of a fatty insulating substance, which is formed by two types of glial cells: Schwann cells and oligodendrocytes. In the peripheral nervous system Schwann cells form the myelin sheath of a myelinated axon. Oligodend...
The structure of a neuron is seen to consist of two separate functional regions, or compartmentsthe cell body together with the dendrites as one region, and the axonal region as the other. Axonal region. The axonal region or compartment, includes the axon hillock, the initial segment, the rest of the axon, and the axon...
Axonal initial segment. The axonal initial segment (AIS) is a structurally and functionally separate microdomain of the axon. One function of the initial segment is to separate the main part of an axon from the rest of the neuron; another function is to help initiate action potentials. Both of these functions support n...
The AIS is highly specialized for the fast conduction of nerve impulses. This is achieved by a high concentration of voltage-gated sodium channels in the initial segment where the action potential is initiated. The ion channels are accompanied by a high number of cell adhesion molecules and scaffold proteins that ancho...
Axonal transport. The axoplasm is the equivalent of cytoplasm in the cell. Microtubules form in the axoplasm at the axon hillock. They are arranged along the length of the axon, in overlapping sections, and all point in the same directiontowards the axon terminals. This is noted by the positive endings of the microtubu...
Myelination. In the nervous system, axons may be myelinated, or unmyelinated. This is the provision of an insulating layer, called a myelin sheath. The myelin membrane is unique in its relatively high lipid to protein ratio. In the peripheral nervous system axons are myelinated by glial cells known as Schwann cells. In...
Axon terminals. An axon can divide into many branches called telodendria (Greek for 'end of tree'). At the end of each telodendron is an axon terminal (also called a terminal bouton or synaptic bouton, or ). Axon terminals contain synaptic vesicles that store the neurotransmitter for release at the synapse. This makes ...
Action potentials. Most axons carry signals in the form of action potentials, which are discrete electrochemical impulses that travel rapidly along an axon, starting at the cell body and terminating at points where the axon makes synaptic contact with target cells. The defining characteristic of an action potential is ...
Extracellular recordings of action potential propagation in axons has been demonstrated in freely moving animals. While extracellular somatic action potentials have been used to study cellular activity in freely moving animals such as place cells, axonal activity in both white and gray matter can also be recorded. Extr...
In addition to propagating action potentials to axonal terminals, the axon is able to amplify the action potentials, which makes sure a secure propagation of sequential action potentials toward the axonal terminal. In terms of molecular mechanisms, voltage-gated sodium channels in the axons possess lower threshold and ...
Extracellular signaling. The extracellular signals that propagate through the extracellular matrix surrounding neurons play a prominent role in axonal development. These signaling molecules include proteins, neurotrophic factors, and extracellular matrix and adhesion molecules. Netrin (also known as UNC-6) a secreted p...
Cytoskeletal dynamics. The neurite with the lowest actin filament content will become the axon. PGMS concentration and f-actin content are inversely correlated; when PGMS becomes enriched at the tip of a neurite, its f-actin content is substantially decreased. In addition, exposure to actin-depolimerizing drugs and tox...
Cells called guidepost cells assist in the guidance of neuronal axon growth. These cells that help axon guidance, are typically other neurons that are sometimes immature. When the axon has completed its growth at its connection to the target, the diameter of the axon can increase by up to five times, depending on the s...

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