Paul Emil Flechsig (29 June 1847,

Zwickau Zwickau (; ) is the fourth-largest city of Saxony, Germany, after Leipzig, Dresden and Chemnitz, with around 88,000 inhabitants,. The West Saxon city is situated in the valley of the Zwickau Mulde (German: ''Zwickauer Mulde''; progression: ), ...

Kingdom of Saxony The Kingdom of Saxony () was a German monarchy in Central Europe between 1806 and 1918, the successor of the Electorate of Saxony. It joined the Confederation of the Rhine after the dissolution of the Holy Roman Empire, later joining the German ...

– 22 July 1929,

Leipzig Leipzig (, ; ; Upper Saxon: ; ) is the most populous city in the States of Germany, German state of Saxony. The city has a population of 628,718 inhabitants as of 2023. It is the List of cities in Germany by population, eighth-largest city in Ge ...

) 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, defin ...

psychiatrist A psychiatrist is a physician who specializes in psychiatry. Psychiatrists are physicians who evaluate patients to determine whether their symptoms are the result of a physical illness, a combination of physical and mental ailments or strictly ...

and

neuropathologist Neuropathology is the study of disease of nervous system tissue, usually in the form of either small surgical biopsies or whole-body autopsies. Neuropathologists usually work in a department of anatomic pathology, but work closely with the cli ...

. He is mainly remembered today for his research of myelinogenesis.

Biography

Born in

, he received his education at the

University of Leipzig Leipzig University (), 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 1409 by Frederick I, Electo ...

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 myelinogenesis. 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 psychiatric ...

and Oskar Vogt (mentor to Korbinian Brodmann). Flechsig was the treating psychiatrist for Daniel Paul Schreber, 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 psychopathology, pathologies seen as originating fro ...

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

myelin Myelin Sheath ( ) is a lipid-rich material that in most vertebrates surrounds the axons of neurons to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. The myelinated axon can be lik ...

. 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 that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...

(as Korbinian Brodmann did) but by order of myelination. 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 support goal-directed behavior, by regulating thoughts and actions thro ...

and

working memory Working memory is a cognitive system with a limited capacity that can Memory, 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 m ...

. 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 cell (biology), cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce Action potential, electrical ...

reactions in the brain and the

retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...

. Flechsig's fasciculus or Flechsig's tract is a neurological structure which conveys

proprioceptive Proprioception ( ) is the sense of self-movement, force, and body position. Proprioception is mediated by proprioceptors, a type of sensory receptor, located within muscles, tendons, and joints. Most animals possess multiple subtypes of propri ...

information from the body to the

cerebellum The cerebellum (: cerebella or cerebellums; 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 it or eve ...

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 Scientists from the Kingdom of Saxony German neuroscientists Leipzig University alumni Academic staff of Leipzig University Neuropathologists