- Les
biographies de
neurologues
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- Johannes Müller professor at the
University of Berlin in anatomy, physiology, and
pathology, was one of the leaders of the 19th
century school of physiology in Germany. He was
born in Coblenz into a shoemaker's family, was
educated in the faith of the Roman Catholic
Church in a stormy period of European history,
and at 10 years of age, entered a venerable
Latin seminary of the Jesuits. Proficiency in
Latin and Greek, skill in mathematics, and a
self-developed interest in biology and zoology
were forces which contributed to his turning
from a life in the church to the medical
sciences. After serving for a year as a
volunteer in the army, in 1819 Muller began his
higher education at the University of Bonn. The
study of respiration of the fetus based upon
experimental observations, which won him a prize
in competition, was an early example of his
abiding curiosity in the unraveling of
physiological phenomena. He graduated MD from
Bonn in 1822, presenting an inaugural thesis on
the laws of motion. He then proceeded to Berlin
to pass the state examination for a physician's
license. While in Beilin, Müller made the
acquaintance of Rudolphi, physiologist at the
university, who spoke for recognition of the
importance of anatomy in physiological
investigation.
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- Müller returned to Bonn and established
himself in private practice. He was impressed,
nevertheless, with opportunities for the
full-time professional pursuit of anatomy and
the need to strengthen the union between natural
philosophy and experimental physiology. In this
endeavor, he became privatdocent on the faculty,
took up the study of the sense organs and the
nervous system, prepared a communication in
Latin on the minute structure and anatomy of
glands throughout the animal kingdom, and
resolved a controversy between the adherents of
Malpighi and Ruysch over the structure of
glands. It was soon apparent that practice was
not Müller's basic interest. Rather, he
chose the academic road, where advancement was
rapid and productive for him. Only three years
after he received senior professorial status at
Bonn, he applied for and was successful in
obtaining the prized professorship of anatomy,
physiology, and pathology vacated by Rudolphi
upon retirement in Berlin. Müller remained
in Berlin (meanwhile ignoring solicitations from
other universities), until he resigned in 1848
while serving as rector of the university. He
went into retirement, plagued by despondency and
failing health. Because he died ten years later
on his appointed day, the evidence suggests
suicide. This act is partially understandable.
In spite of his complete acceptance of
experimental science, he was a dreamy mystic and
proponent of the vitalistic theory, believing in
the existence of a dynamic force insusceptible
to mechanical or physical measurement.
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- Müller's interpretation of physiology,
which exerted a profound influence on scientific
medicine, was all-inclusive and embraced
biology, comparative anatomy, chemistry,
psychology, pathology, zoology, paleontology,
and embryology. The number of scientific areas
explored was surpassed only by the quantity and
quality of his communications to scientific
periodicals or prepared as monographs or texts.
Several were translated into English for wider
dissemination and easier accessibility. If
Müller lacked one attribute in academic
life, it was the charm of an engaging lecturer.
The deficiency was minor, however; as if to
compensate, his scientific "inspiration"
profoundly influenced a number of brilliant
pupils who were trained by him to reason as
natural scientists. The list of followers
includes Brücke, Du Bois Reymond,
Helmholtz, Kölliker, Henle, and especially
Schwann, who enunciated the cellular theory, and
Virchow, the father of cellular pathology.
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- The first volume of Müller's most
famous treatise, The Handbook of Human
Physiology, appeared in 1834 and was translated
into English in 1837. He summarized important
advances in preceding decades and rendered
current each subject, with integration of
contributions made by chemistry and physical
instruments. Consequently, physiology emerged
under his leadership as a specific discipline
among the medical sciences. Seizing every method
of observation and utilizing mathematics and
physics to investigate the intellect and the
senses, he entertained the conviction that
physiological investigation must exploit
psychological understanding in interpreting mind
and the soul. Although his law of specific nerve
energies was propounded first at Bonn in 1826,
his Physiology included a mature presentation of
his conclusions.
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- «If the nerves are mere passive
conductors of the impressions of light, sonorous
vibrations, and odours, how does it happen that
the nerve which perceives odours is sensible to
this kind of impressions only, and to no others,
while by another nerve odours are not perceived:
that the nerve which is sensible to the matter
of light, or the luminous oscillations, is
insensible to the vibrations of sonorous bodies;
that the auditory nerve is not sensible to
light, nor the nerve of taste to odours; while,
to the common sensitive nerve, the vibrations of
bodies give the sensation, not of sound, but
merely of tremours? These considerations have
induced physiologists to ascribe to the
individual nerves of the senses a special
sensibility to certain impressions, by which
they are supposed to be rendered conductors of
certain qualities of bodies, and not of
others.
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- A consideration of such facts could not but
lead to the inference that the special
susceptibility of nerves for certain impressions
is not a satisfactory theory, and that the
nerves of the senses are not mere passive
conductors, but that each peculiar nerve of
sense has special powers or qualities which the
exciting causes merely render manifest.
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- Sensation, therefore, consists in the
communication of the sensorium, not of the
quality or state of the external body, but of
the condition of the nerves themselves, excited
by the external cause».
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- Müller supplied experimental
proof in the frog for the Bell-Magendie doctrine
of the function of spinal nerves, to wit:
anterior roots carry centrifugal fibers and the
posterior roots carry centripetal fibers. The
correct experimental procedure was selected by
Müller to support his physiological
experience and intuitive judgment.
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- «The presence of sensory and motor
nerves in the same trunk is one of the most
important phenomenon in physiology. Charles Bell
was the first to suggest that the posterior
roots of a ganglion of the spinal nerves have
only sensory functions and the anterior roots
have only motor function, and that the fibers of
these roots supply the skin and the muscles from
one nerve tract.
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- Frogs seem best suited for the experiments;
they withstand the exposure of the spinal canal,
the nerves remain sensitive for very long
periods, Sand the thick nerve roots of the lower
extremities run a protracted and separate course
in the spinal canal before they unite into
larger trunks.
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- In each repetitive experiment we come to the
conviction that irritation of the posterior root
fails to produce the slighest contraction in the
lower extremities. The same can be shown for the
posterior roots that supply the upper
extremities.
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- On the other hand, at the slighest
stimulation of the anterior roots, the muscles
twitch and contract. When the roots are
separated from the spinal cord, any irritation
produces energetic twitching».
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- The results of these experiments leave no
doubt that Bell's law is valid and correct.
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- Another study in anatomy and physiology led
to the discovery, in selecting amphibians, of
four distinct hearts of the lymphatic system.
The pulsating organs were encountered in the
quest for frog lymph for demonstration to
students. Posterior lymphatic hearts were
identified first.
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- «These are most easily found in the
frog, but they exist also in the toad, the
salamander, and the green lizard; probably in
all amphibia, the naked as well as those
provided with scales. The organ is double, and,
in the frog, lies on each side, behind the
articulation of the os lemons, near the anus, in
the regio iscniadica. The organ lies immediately
under the skin Its regular contractions may be
seen more distinctly when this is removed. The
arteries and vena ischiadica, the largest
vessels in the thigh, run immediately underneath
the organ, but the motion of the blood in these
vessels has no influence upon it. The
contractions are neither synchronous with the
motions of the heart, nor with those of the
lungs . . . . They [contractions]
continue after the removal of the heart . . . .
The pulsations of the two organs, on the right
and left sides, sometimes alternate at irregular
intervals.
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- The anterior lymphatic hearts lie on each
side, upon the great processus transversus of
the third vertebra . . . . They are round in
shape and connected with the contiguous vein.
The fluid which is discharged into the vein is
colourless».
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- In physiological chemistry, Müller
isolated chondrin and gluten. In zoology, he
studied the amphioxus, the starfish, sea
cucumbers, and sharks; he became a
paleontologist and studied fossil fishes,
mammalia, echinites, and snails. In embryology,
the paramesonephric duct (Müller's duct)
was discovered by him in the developing chick.
Müller's law of the eccentric projection of
sensations from the peripheral sense organs to
other nerve terminals, a theory of color
contrast, and his work on strabismus and a
comprehension of binocular vision represent
borderline subjects between neurology and
ophthalmology. An explanation of the color
sensations (pressure-phosphenes), produced by
pressure on the retina, was described in
Physiology of Sight of Men and Animals.
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- «When pressure is applied with the
finger tips to the lateral areas of the closed
eyes, light rings appear in the periphery of the
darkened field of vision. Lateral pressure on
the right eye produces a light ring in the
periphery on the medial side, and the lateral
pressure on the left eye produces a light ring
on the medial side of the field of vision. If
the pressure is applied to the medial sides of
either eye, the light rings appear again at the
extreme periphery of the field of vision.
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- We conclude from these experiments that the
retina of either eye is identical and forms one
and the same subjective organ of vision; all
parts lying in a certain meridian and at a
certain distance from the central point of the
eye are identical with the corresponding parts
of the retina of the opposite eye, lying in the
same meridian and at the same distance from the
central point of the retina of that
eye».
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- In demonstrating the harmony which existed
between the pathological and the embryonic
development of tumors, Müller was one of
the first to employ the microscope. Until his
time, the prevailing view considered cancer to
be a general disease and the tumor a local
manifestation. Müller showed that the
cancer consisted of a growth of abnormal cells.
He began a program of tumor identity, but death
prevented its completion.
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- «According to Schwann, all the tissues
in the embryo are formed from cells, which are
themselves developed from nuclei; growth being
the result of fresh formations of cells, which
afterwards undergo transformation into other
tissues. These observations led the author to
examine morbid growths very carefully; both
those in which no cells had hitherto been
discovered, and also such as were known to
present a cellular structure with a view to
determine the presence of nuclei in the walls,
or within the interior of the cells; while the
author further hoped to verify the truth of that
principle which Schwann has laid down. By
employing a high magnifying power, cells were
observed in many morbid growths in which they
were not previously known to exist, as in
collonema, in many varieties of carcinoma, and
in enchondroma. In most growths presenting a
cellular structure, with the exception of
cholesteatoma and cellular polypi, the nuclei of
the cells were discovered, situated either in
their walls or in their interior: in many
instances, too, young cells were formed within
older ones, as was the case in sarcoma,
enchondroma, carcinoma, and collonema. Thus,
then, as might have been anticipated, did the
examination of morbid structures confirm
Schwann's observations touching the development
and growth of healthy tissues.
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- Whether the carcinomatous diathesis be
peculiar and distinct from all others, or
whether, under certain circumstances, any other
structure may pass into the state of carcinoma,
still the same question presents itself;-is
there any other characteristic of carcinomatous
growths than such as are derived from their
minute structure, or from the process of their
development? The solution of this question must
always be the grand problem in the anatomy of
morbid growths. The examination of numerous
specimens of carcinoma has taught the author
that they, are, indeed, possessed of certain
peculiar anatomical characters, which may serve
to identify them; and, further, that these
characters are distinguishable, on making a
section of the growth, either by the naked eye,
or at any rate by the aid of a common magnifying
glass».
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- In 1834, Muller founded the Archiv für
Anatomie, Physiologie und Wissenshaftliche
Medicin, later known as Muller's Archiv. He was
a member of almost all scientific bodies in
Germany and of many foreign societies, including
the Philosophical Society of Philadelphia and
the American Academy of Arts and Sciences of
Boston. He received the Copley medal of the
Royal Society of London and was honored by the
kings of Prussia, Sweden, Bavaria, and
Sardinia.
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- 1. Virchow, R.: Elogy of John nnes Muller
(Ger), Berlin: A. Hirschwald, 1858, translated
by A. M. Adam, Edinburgh Med J 4:452-463;
527-544 (July) 1858.
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- 2. Müller, J.: Handbook of Human
Physiology (Ger), Coblenz: J. Holscher,
1834-1840, translated by W. Baly, London: Taylor
& Walton, 1837.
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- 3. MüllIer, J.: Confirmation of Bell's
Law (Ger), Notiz Geb Natur Heslk 30:113-122,
1831.
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- 4. Müller, J.: On the Existence of Four
Distinct Hearts, Having Regular Pulsations,
Connected With the Lymphatic Sys,tem, in Certain
Amphibious Animals (Ces), Philos Trans, pt 1, pp
89-94, 1833.
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- 5. Müller, J.: Physiology of Sight of
Men and Animals (Cor), Leipzig: K. Knobloch,
1826.
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- 6. Müller, J.: On the Nature and
Structural Characteristics of Cancer (Ger),
Berlin: G. Reimer, 1838, translated by C. West,
London: Sherwood, Gilbert, & Piper,
1840.
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