Paul Emil Flechsig (29 June 1847,

Zwickau Zwickau (; is, with around 87,500 inhabitants (2020), the fourth-largest city of Saxony after Leipzig, Dresden and Chemnitz and it is the seat of the Zwickau District. The West Saxon city is situated in the valley of the Zwickau Mulde (German: ' ...

Kingdom of Saxony The Kingdom of Saxony (german: Königreich Sachsen), lasting from 1806 to 1918, was an independent member of a number of historical confederacies in Napoleonic through post-Napoleonic Germany. The kingdom was formed from the Electorate of Sax ...

– 22 July 1929,

Leipzig Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as ...

) was a German

neuroanatomist Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defi ...

psychiatrist A psychiatrist is a physician who specializes in psychiatry, the branch of medicine devoted to the diagnosis, prevention, study, and treatment of mental disorders. Psychiatrists are physicians and evaluate patients to determine whether their sy ...

and neuropathologist. He is mainly remembered today for his research of

myelinogenesis Myelinogenesis is the formation and development of myelin sheaths in the nervous system, typically initiated in late prenatal neurodevelopment and continuing throughout postnatal development. Myelinogenesis continues throughout the lifespan to ...

Biography

Born in

, he received his education at the

University of Leipzig Leipzig University (german: Universität Leipzig), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December ...

and in 1884 became professor of psychiatry there. In 1882, he became director of the Clinical Institute of Psychiatry and Neurology at Leipzig. He made personal investigations of the European systems for the treatment of the insane, on which he was a recognized authority. He spent over fifty years of his medical career at Leipzig. Although Flechsig contributed much in his study of neurological disorders, he is mainly remembered today for his research of

. Among his students were

Emil Kraepelin Emil Wilhelm Georg Magnus Kraepelin (; ; 15 February 1856 – 7 October 1926) was a German psychiatrist. H. J. Eysenck's ''Encyclopedia of Psychology'' identifies him as the founder of modern scientific psychiatry, psychopharmacology and psych ...

and Oskar Vogt (mentor to

Korbinian Brodmann Korbinian Brodmann (17 November 1868 – 22 August 1918) was a German neurologist who became famous for mapping the cerebral cortex and defining 52 distinct regions, known as Brodmann areas, based on their cytoarchitectonic (histological) char ...

). Flechsig was the treating psychiatrist for

Daniel Paul Schreber Daniel Paul Schreber (; 25 July 1842 – 14 April 1911) was a German judge who was famous for his personal account of his own experience with schizophrenia. Schreber experienced three distinct periods of acute mental illness. The first of th ...

, whose memoir inspired

Sigmund Freud Sigmund Freud ( , ; born Sigismund Schlomo Freud; 6 May 1856 – 23 September 1939) was an Austrian neurologist and the founder of psychoanalysis, a clinical method for evaluating and treating pathologies explained as originating in conflicts i ...

to publish a detailed analysis of the case in 1911. Flechsig's work has still not been rediscovered widely but his map was reprinted and discussed in Fuster's "Cortex and Mind".

Myelinogenesis Myelinogenesis is the formation and development of myelin sheaths in the nervous system, typically initiated in late prenatal neurodevelopment and continuing throughout postnatal development. Myelinogenesis continues throughout the lifespan to ...

is a technique he pioneered in which he studied brains of the late term fetus and newborn by staining for

myelin Myelin is a lipid-rich material 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 ...

. Between about two months before and after birth, most of the cerebral cortex becomes myelinated. The order in which this happens appears to reflect the evolutionary order of mammals from less to more complex. He derived a map of the cerebral cortex divided not by

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures v ...

(as

did) but by order of

myelination Myelin is a lipid-rich material 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 ...

. Flechsig divided the cortical regions into: # an early myelinating primitive zone, which includes the motor cortex and the visual, auditory, and somatosensory cortex; # a field bordering the primitive zone that myelinates next; # a late-myelinating zone, which he called “association”.Kolb & Whishaw: ''Fundamentals of Human Neuropsychology,'' 2003 The last area of the human cerebral cortex to myelinate is the Dorsolateral Prefrontal cortex. (Flechsig #45, Brodmann areas 9 & 46). This region continues to develop in adolescence and adulthood it is related to

executive function In cognitive science and neuropsychology, executive functions (collectively referred to as executive function and cognitive control) are a set of cognitive processes that are necessary for the cognitive control of behavior: selecting and succe ...

and

working memory Working memory is a cognitive system with a limited capacity that can hold information temporarily. It is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term memory, ...

. In a 1927 review in the Journal of The American Medical Association (JAMA) of his last monograph one finds the following: The "Paul-Flechsig-Institute of Brain Research" at the

is an institution established in 1974 in tribute to Flechsig. The institute's scientific emphases is on cellular and molecular aspects of neurodegenerative diseases and

glial Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system (brain and spinal cord) and the peripheral nervous system that do not produce electrical impulses. They maintain homeostasis, form myel ...

reactions in the brain and the

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which the ...

Flechsig's fasciculus The spinocerebellar tract is a nerve tract originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum. Origins of proprioceptive information Proprioceptive information is obtained by Golgi tendon organs and mu ...

or Flechsig's tract is a neurological structure which conveys

proprioceptive Proprioception ( ), also referred to as kinaesthesia (or kinesthesia), is the sense of self-movement, force, and body position. It is sometimes described as the "sixth sense". Proprioception is mediated by proprioceptors, mechanosensory neurons ...

information from the body to the

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebe ...

Bibliography

* Die Leitungsbahnen im Gehirn und Rückenmark des Menschen auf Grund entwicklungsgeschichtlicher Untersuchungen dargestellt (1876)
Ueber Darstellung und chemische Natur des Cellulosezuckers
Zeitschrift für Physiologische Chemie 7: 523-540 (1882–83) * Die Irrenklinik der Universität Leipzig in den Jahren 1882-86 (1887) * Ueber eine neue Färbungsmethode des centralen Nervensystems und deren Ergebnisse bezüglich des Zusammenhanges von Ganglienzellen und Nervenfasern. Archiv für Physiologie: 537-538 (1889) * Gehirn und Seele (1896) * Die Localisation der geistigen Vorgänge insbesondere der Sinnesempfindungen des Menschen: Vortrag gehalten auf der 68. (1896) * Anatomie des menschlichen Gehirns und Rückenmarks auf myelogenetischer Grundlage (1920) * Die myelogenetische Gliederung der Leitungsbahnen des Linsenkerns beim Menschen. Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig: Mathematisch-Physische Klasse 73: 295-302 (1921)

References

External links

Picture, biography and bibliography
in the Virtual Laboratory of the Max Planck Institute for the History of Science
Official site of the Paul-Flechsig-Institute of Brain Research
in Leipzig (mainly German, some English)

at

Who Named It ''Whonamedit?'' is an online English-language dictionary of medical eponyms and the people associated with their identification. Though it is a dictionary, many eponyms and persons are presented in extensive articles with comprehensive bibliograp ...

; retrieved 4 May 2009 {{DEFAULTSORT:Flechsig, Paul 1847 births 1929 deaths People from Zwickau People from the Kingdom of Saxony German neuroscientists Leipzig University alumni Leipzig University faculty