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Que es electroneurobiologia? La atmosfera intelectual Conceptos tecnicos principales El descubrimiento de la Doppelrinde
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Enviado por admin
Código ISPN de la Publicación: EplupuVVZkgddOYoVy
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| Resumen: Aqui se explican muy esquematicamente, en castellano, ingles y aleman, la historia de la tradicion neurobiologica argentino-germana y algunos puntos especificos de las relaciones mente-cerebro. |
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1. Introducción
El
17 de julio de 1899 llegó Christofredo Jakob a este laboratorio, flamante por
entonces. El sabio venía de Erlangen, a insertarse en el proyecto de forjar
nuestro país sobre sólidas bases científicas. Proyecto crudo, de trasplante
sin rodeos, a menudo al borde del prejuicio de creer que el criollo, solo, no
podría lograr nada. Pero Jakob se quedó hasta morir -cincuenta y siete años-,
formó familia, afectos y casi cinco mil intelectuales; exploró regiones
ignotas de la Patagonia y los Andes, y produjo descubrimientos científicos tan
adelantados que muchos fueron re-descubiertos en el extranjero entre treinta y
sesenta años después, y otros hoy marcan el futuro rumbo de la ciencia del órgano
cerebral.
2. ¿Qué es electroneurobiología?
El
estado de los campos eléctricos cerebrales es la vía común adonde desemboca
la neuroquímica.
Toda
la complejidad neuroquímica del cerebro se vierte sobre el
estado de sus campos eléctricos. Sus doscientas mil especies químicas, sus
casi doscientos neurotransmisores y neuromoduladores, se hallan al servicio de
esculpir un estado dinámico en esos campos eléctricos. (No es necesario
explicar todo esto aquí; pero, para connoisseurs, cabe consignar que lo hacen
por vía de las fluctuaciones integradas de los orbitales electrónicos en
reacción a la movilización fisiológica de portadores de carga). Las
variaciones de estos campos eléctricos determinan las diferentes
caracterizaciones subjetivas (emotivas, o "movientes", como placeres y
dolores; o sólo señalantes, como muchas perceptualidades al estilo de tonos y
colores; o bien combinadas) que el alma lee.
La
electroneurobiología no es ninguna ciencia del alma, de cuyos arcanos todo lo
ignora excepto que no lee química: las producciones del cerebro que
directamente generan caracterizaciones subjetivas no son moléculas ni sus
reacciones, sino el colectivo electrónico a cuyo estado la presencia de
aquellas contribuye. Átomos y moléculas suelen reaccionar entre sí y la
selección natural selecciona sus organizaciones, pero éstas y aquéllas son sólo
excusas instrumentadas para modular, en los organismos controlados por
psiquismo, los contenidos sensoperceptuales (noémata, plural de nóema).
Independientemente de su "lectura" o aprehensión (nóesis).
La
electroneurobiología busca describir en qué difieren los estados físicos que
generan la aprehensión-de-un-rojo, de los que generan la aprehensión-de-un-miedo,
o de un verde, o de un placer, o de cierto olor, cuando estas sensaciones son
imaginadas, recordadas o percibidas. También busca describir en qué difieren
todos ellos de la carencia de contenidos de consciencia, cuando fármacos que
producen anestesia general (por sí mismos, o "gatillando" receptores)
tornan más flúida la membrana que compartimenta al tejido gris. ¿Cómo afecta
este cambio a aquellos estados físicos que generan las diferentes
caracterizaciones subjetivas, impidiéndoles obrar? ¿Les impone un estado
similar al dormir sin soñar, a ese sueño profundo que el electroencefalograma
reconoce por sus típicas ondas lentas? Todos los psicolépticos que empleamos,
todos los agentes de anestesia general que utilizamos, son eficaces, pero no
sabremos de qué manera logran su acción hasta no describir, allende su química,
esos procesos electroneurobiológicos. Y no sólo hasta no describirlos tal como
son en la actualidad, sino además tal como han sido en su desarrollo evolutivo:
es cuestión de describir, por ejemplo, la selección natural del dormir llamado
profundo (impelida con el desarrollo immunitario de la defensa febril, en el Jurásico);
o de la producción de procesos sobre nuevos ejes variativos (en distintas
formas animales) donde nuevas especies de emociones hayan podido intensificarse
y luego remitir, de modo de permitir a su vez la selección natural de la
oportuna producción de estas variaciones afectantes en las diferentes
situaciones típicas de las biografías.
Hoy
todavía desconocemos por qué se duerme con pérdida de conocimiento (o de
retención), por qué se sueña, de dónde viene el relato de un sueño, el guión
de un delirio, el contenido de una alucinación, el efecto de los psicofármacos,
la fulmínea acción de la anestesia general o de un leve enfriamiento cerebral,
el que ciertas moléculas producidas por un cerebro en cierto estado produzcan
depresión y otras moléculas euforia, y aun otras una extraña ternura.
Curamos, y seguiremos curando, sin ese conocimiento; identificaremos genes, los
que producen ciertas moléculas, y otras fuentes que asimismo allegan disrupción
química al órgano cerebral, y podremos hasta contrarrestar sus efectos cuando
los juzguemos deletéreos. Pero un avance realmente magno exige establecer qué
estados físicos producen qué caracterizaciones subjetivas. Electroneurobiología
es aquella rama de la neurobiología centrada en esta crucial pregunta.
3.La atmósfera intelectual
El
viejo Hospicio de las Mercedes (desde hace ya mucho Hospital Dr. José Tiburcio
Borda) y el algo más viejo Hospital de Alienadas (ya también tradicionalmente
Hospital Dr. Braulio Aurelio Moyano), son hospitales docentes. Contiguos, uno
dedicado principalmente a varones y el otro a mujeres, han recibido y reciben
pacientes neurológicos y psiquiátricos, de patologías simples o, muy a
menudo, combinadas (las que, por ende, no admiten separación asistencial). Son
docentes porque su función, aparte de curar, es enseñar a curar, básicamente
por convenio con las principales casas de altos estudios; y para enseñar
investigan. Nuestra patria nunca ha sido tan colosalmente rica como para
abandonar la investigación fundamental, pagando sus noticias a complacientes
proveedores foráneos; y si la abandonara nunca será rica. Hacia épocas de la
primera Guerra Mundial, sin psicofármacos y en un necesario auge del
hospitalismo, cada Hospicio cobijaba unos seis mil pacientes (hoy la cuarta
parte, pero por internaciones harto más breves, atendiendo así a muchos más
pacientes) y, para corroborar e interpretar las observaciones en los vivos,
proporcionaba casi cuatrocientos cerebros por año. Acompañado por lo común
cada uno con su historia clínica, redactada con acuciosidad y penetración.
Ninguna otra institución humana provee ésto a la humanidad. Fue y es, así, en
sus autopsias, que los muertos enseñan a los vivos. Pero aprender requiere
contextuar, y esos estudios neurobiológicos tomaron aquí contexto en una
transdisciplinariedad humanístico-científica, de amplitud renacentista.
Caracterizóse así la mayor tradición neurobiológica hispanoamericana,
conocida informalmente como Escuela Neurobiológica Argentino-Germana, ligada
por estrechos vínculos con la tradición normalista argentina, con la Facultad
de Filosofía y Letras de la Universidad de Buenos Aires y con la Facultad de
Humanidades de La Plata, con el Círculo Médico Argentino y con la Sociedad de
Psicología de Buenos Aires, con la rica tradición paleontológica platense y
con las investigaciones del Jardín Zoológico municipal, con la Sociedad Científica
Argentina, con la Asociación Nacional del Profesorado y con las labores en
criminología y medicina legal, a más de las correspondientes facultades del área
biomédica. La inédita fecundación mutua se sostenía en el compartido
maravillarse acerca de qué es persona, y en la compartida conciencia de la
necesidad de los recursos intelectuales ajenos para obrar. Dimos así a prensas
en Europa la mayor publicación argentina de resultados investigativos hasta la
fecha (los dos volúmenes Das Menschenhirn y Vom Tierhirn zum Menschenhirn:
Lehman Vlg., Munich, 1911) y aportamos importantísimas contribuciones, algunas
mencionadas más abajo en esta misma Página; a menudo, olvidadas en el
extranjero por nuestra situación, remota para ellos, y por el empeño en
imprimir en nuestra lengua.
4.Main Technical Ideas - Conceptos técnicos principales:
El
siguiente texto pertenece a la obra de Alicia Ávila y M. Crocco "Sensing:
a new fundamental action of nature" (Inst. for Advanced Study: Buenos
Aires, 1996), pág. 22 a 26, y puede citarse consignando esa fuente. Más
abajo reproduzco también el índice de ese libro - Sorry: I still have this
page on its making. I have had no spare time to render the following paragraphs
into Spanish. Yet they afford the succint conceptual landscape owed to whom
wishes to know what the matter is about. They are excerpted from the synoptic
monograph from Alicia Ávila and M. Crocco "Sensing: a new fundamental
action of nature" (Inst. for Advanced Study: Buenos Aires, 1996), pp. 22 a
26; they may be citated quoting such a source. The table of contents of that
book is also reproduced hereinafter.]
Iron-branded
by an all-penetrating naturalist-humanist transdisciplinarity which, for
scientific furtherance, demands the personal sensitivity proper to wrestle with
philosophical and culturological problems (that is to say: peculiarly
understood, not as a juxtaposition of specialists, but in the sense cultivated,
say, by Weber, Fechner and von Helmholtz), a rather secluded South-American
tradition in neurophysics waxed much bent on what, afterwards, became called
bioelectricity and dielectrics.
It was
prepared by local studies of potent "fish batteries" and ensuing
chemoelectricity theses, still in the XVIIIth century; and by
Faraday’s and Young’s "new physics", as imparted in the
"unforgettable lessons" by dielectricist Octavio Fabrizio Mossotti,
from his Experimental Physics chair in Buenos Aires between 1828 and 1835.
This last was the same year that, in
Paris, Felix Dujardin first described the intracellular milieu, such awesome
jelly lacking visible composition yet doubtlessly organized, as "une
substance appelée sarcode"; at whose ability, when making brains, of
bringing sentience-contents forth, we never omitted wondering. As the tradition
became the so-called Argentine-German Neurobiological School, incepted since
1879 though fully fledged only since 1899, this endeavour struck roots in
momentous electroneurobiological experiments. I. e., in the much-needed,
worldwide-first electrostimulation mapping of an exposed, conscious human brain
heroically prolonged during eight months (from September 1883 to May 1884)
against overwhelming odds that risked the subject's death and the experimenter's
loss of career and marriage, and silenced over a century by a medical-politician
plagiarist. [It is detailed in the next heading on this Page: MS] In this
traditionated atmosphere, contrarily to the aforesaid obloquious conviction,
some of us (initially the physicists), in the past thirty years reacted against
those adventitious limiting features in neurodynamics.
In doing
it, no doubt indeed mostly by dint of our very remoteness, these physicists felt
uncompelled by the most cumbrous cultural expectancies.
Certainly, neither behaviourism nor
neuronism thundered here. (Behaviourism was expressly rejected in 1907: Alicia Moreau de Justo,
"La vida y los fenómenos psíquicos", El Libro (Buenos Aires) 2
(1907), 363-371.)
Nor emergentistic theories,
pronouncing psychisms to be mere perspectives or equivalent "aspects"
own of some higher level description. Or either (upon certain grasping of the
physical being as an "observer"-posited logical predication, that
"instantiates properties" (Nota 3) and, accordingly undistinguishing
the causative actuality of the present from unexisting future or past
situations, abandons the notion of absolute time at all) pronouncing psychisms
to be "productive creations" whether of the mere complexity
(hodologies) or of the mere simplicity (immateriality).
Nor,
outlooks glad to forgo natural facts by self-limiting to analyze formulations
and their use, as if being physical just were to be the value of a variable; or,
barely, an excuse for making true and false (including universally and
existentially quantified) statements about them.
Nor the derisive natural-philosophy
vogue, of minding one-witness, causally-effectual physical facts as
"qualia" or "unreduced phenomenal properties", whose privacy
is arbitrarily equated to powerlessness. (Nota 4)
Yet, we were also stimulated by
certain explosive internal conceptual tension regarding time.
This conceptual tension was
bequeathed by one of the tradition's founders. A gifted polymath, as all them,
he was also the tradition's harbinger and chief mentor. That founder was a
neurobiologist devoting himself since 1906 to model neuropilar psychogenesis
(neuropil is the bulky "fiber" feltwork, or drenched craticula,
interjacent amidst the neurons’ bodies) on reverberating interference patterns
as collective or gestalt excitation modes, whose interference defines
segmentations localizable, translationally invariant, and mutually impenetrated.
His name was Prof. Christfried Jakob (1866-1956). As an anatomist who conceived
organisms as self-relaxing oscillatory systems, he acutely sensed the prelation
of time processes to yield spatial aggrupations, including what he called
representational atomicities.
So Prof. Jakob emphasized the
time-kerned seriation of chemodiffusion carrier waves making sensorimotor
rhythms, as the periodic forcing (of coupled nonlinear oscillators) foundation
of the spatial anatomy. Just like as interfering neuroactivity defines segmented
contents. Not inversely, as on more "stocky", still customary
anatomical building blocks.
Both in evolutionary and
developmental differentiation and in actual functioning, Jakob’s principle to
describe any biological organization of physical effects (Nota 5) was the
epicyclic modulation of concentrational oscillations of chemoreactants into
cycles, rhythms, kinesias, praxias, gnosias and symbolias (a series of technical
terms to be made clearer on subsequent pages), ranked encaptically as
biochemical carrier waves each bearing the next —"waves woven on the
backs of waves"— and localized, through self-compartmentation, onto
successive scales. (In fact, "time scales" do not exist. Space or
simultaneous dispersivity has extramental scales, time no, and contrarily to
quantities of force or multitude, "quantities of time" not exist:
nature self-appends from site to site, not self-attaches from instant to
instant, so "more than one present" is but a present reference, a way
of talking, discounted as such only by said taking the physical being as a
posited predication, devising logic as a fundamental structure underlying
physical interactions, or hypostasis; howbeit —in fact— in this universe
proper predication not suffices to acquire actuality. All this shall concern us
below). Thus, Jakob conceived anatomophysiology as what today would rather fit a
dynamic quasi-fractality of epicycles forcing a pattern-forming diversification
of frequency-locking regimes, locked to the physical feasibilities for body
operation over each durational scale. It makes anatomy continuous from
slowly-changing osteology to the intentional combination of alluded
representational atomicites; from tertiary molecular structures down to bodily
acclimatization.
Far off
any iterative, fractal routine, yet these frequency-locking regimes force a
temporal organization in the series of cycles, rhythms, kinesias, praxias,
gnosias and symbolias, where the originating cycles could nowise be
infinitesimal. In it, Jakob posited the boundary conditions that fix the
differential production of the "intonations" which experience is
non-indifferent to (= the evolutionary selection of the correlation with
the survival and reproduction of the life cycles, of: fury, pleasurefulness,
fear, grief and other target-linking emotions, lust, sleepiness, hunger, thirst
and other rebalance-appetizing states, as well as the non-emoting but
signalizing sensoperceptual intonations; a tie that Jakob called biophylaxis),
neither in any special subcellular device, nor in any other, even more complex
arrangement implemented on a larger scale; but in the resonant coupling of those
concentrational oscillations, on which kerned (= nested one within another)
modulations are adaptively impressed.
It must
be taken into account that deploying the "atomic" contents which the
brain provides for a thought; displaying a blinking; moving an arm; growing a
bone; deploying the contents of the chest in embryogeny, and modifying the
patterns of life cycles in phylogeny, could not have been deemed intrinsically
different processes in the anatomo-physiological exposition of said series of
cycles, rhythms, kinesias, praxias, gnosias and symbolias. Their peculiarities
are mainly proper of scales of situational transformation, or "interval
scales".
This
mutual relativity of their "epicycled" dynamics shows certainly in the
regulations attained outside psychisms. E. g., in the compliant accommodation of
the castes of eusocial insects. Each of whose specialized "forms"
compounds the dynamics of both (I) "static" morphologies —namely,
the maturation to different categories of soldiers and workers— and (II) a
repertoire of fixed neurobiological sensibilities that, by default, behave in
each task whose need for the colony is pending of "appeasing" at the
moment (that is: is currently demanded to such caste’s level of ganglionary
sensibility, with no individual simulating any strategic course of the colony).
In life cycles, morphology is deployment. Omnipresently. It orchestrates diverse
intrinsic celerities. Sometimes it behooves, methodologically, to artificially
focuse just on some pair of supporting-supported causal levels (assigned as
"structure and function": the more flitting running as the less
"substantial", or functional); sometimes, to highlight the entire
fractal-like succession of their "epicycled" kernings.
The biological regulations attained
by way of psychism do not situate themselves differently, although they
implement different physical means. Sentience and semovience are amongst the
interactions present in the system. As Jakob described the psychogenetic
landscape in 1907, two or three lustrums after the rediscovery (1890/96) and
international examination (here it was done by Richard Sudnik and Mariano
Alurralde) of Caton’s publication in 1875 of his finding of electric
oscillations intrinsic of the brain activity (Nota 6), the cycles and rhythms at
the basis of the above morphogenetic series, reputed by that time of a
chemoelectrical nature onto which a further vital fluid might (or might not)
have added its own tensional state and relaxations, ratified the fundamental
anatomo-physiological role of the physical oscillations. How do they causally
compound themselves?
As Jakob portrayed them, these
oscillations in the psychism-supporting brain tissue do initially segment a sort
of standing waves, sustained by patterns of local neuroactivity which not
pertain to a single, particular mental content but, as the "standing
waves" interfere or "encroach their feet", enter to cast many.
Unmindful allusion to bounded wholes foreruns object perception. Needfully.
Though non-locally distributed on tissue’s volume and reciprocal interval
reference, these plurally-used "standing waves" are to be observed as
local quasi-periodicities of the nervous "ébranlements". Yet, they at
once enter their mutual, transforming interactions.
Which include those of the sentience,
or physical interactions that produce their nomical effects through their
affecting a non-indifference constitutively circumstanced thereto. Psychisms
operate repositioning segmented objects composed by that sort of standing waves
plus their experienceable intonations, and so they do not process natural
symbolic representations of more elementary data. The existential to be, namely
that one which allows other psychisms, with diverse contents, to be more or less
like it (the difference coming from the different contents, the sameness from
their existential being), and which is absent from extramentalities (whose being
is, therefore, not existential), indissociably appears in nature with the
intonations, whose extramentality admits to be causally swayed by other
extramentalities. This sort of "standing waves", sustained by
reverberating neurobiological macro- and microcircuits, interpenetrate whilst
their temporal organization constitutes that system of segmented, or
individualized, stationarities that Jakob also called representational
atomicities, whose constitutive interactions include the mentioned sentience’s
effects.
Notas
(De los párrafos citados; en la publicación se hallan todas a pie de página,
con la numeración indicada. / Notes of the quoted pages; they are all footnotes
in the printed work, numbered as follows):
3.
The physical traits, characteristically featured by any sort of real thing
—i.e., a photon, as different from an electron—, differ from that thing’s
existence or inexistence. Being or instead not being is a brute factuality. As
such, the determination of actuality is really foreign to, and not included in,
any physical determination of features. Yet no entity lacks identity. This
determination of features —even a cosmological evolution of the causal
resultances, or even evolving modalities of interaction compounding causation
differently at each stage and eventual branch— just distributes regularly the
brute empirical fact whereby there is something rather than instead nothing at
all. That assortment of new features is variegated because actual physical
things (the quantum field system and eclosions) do not form a homogeneous stuff,
as they really —not just as instrumentally posited by classical physics; see
below in the main text— are of diversified sorts (= each real physical
thing is thus found finite), so making nature a "universe"; whereas
their determination of inexistence or existence (= of their present
actuality or "interactivity") depends on that any reality really
exists, and thus cannot consist in said variegation of attributes that
"instantiates properties". Howbeit complexified might said variegation
be. Present actuality is not in turn variegable. Only entire. And fully real;
or, either, wholly absent. The existence apportioned in the physical, finite
realities is never finite in itself, partial, just specific, or incomplete.
Correspondingly, finite entities are never defined after their existence.
Neither the physical determination is causative of actuality (of its field
system or of singular eclosions) nor actuality’s causation is just predicative
of features. This distinction, obscured because the causal determination of
features never runs apart of actuality (= never runs as if the features
were forerunning things, to become amalgamated), is however noticed in the
Western thought up from Aristotle (Analyt. Hyst. 92 b 10), Boetius (appr.
470-525; cf. De Hebdomadibus II), al-Farabî (deceased in Baghdad about 950),
Ibn Sinâ ("Avicenna", 980-1037), a minority of the pre-Renaissance
Schoolmen, and Spinoza (1632-1677: Eth. I, Pr. 24; cf. Pr. 28).
4.
This improper equation presents feelings and perceptualities as caused
constituents of nature that, because of their postulated being non-causal by
themselves (and not, instead, because of their being just incommunicable through
channels), ought to stay restricted to a particular reference frame. (Owing to
that affixing, they should perform as virtual optical images, vanishing if
re-described from moving reference frames; not even operative as their
conjugate, the real images, which do subsist but vary when their observer moves,
as resplendent glitterances, photographable rainbows and skin-taning reflections
on water; the causative action of the components, on the other hand, issuing
from real images yet absent of virtual ones, is of course found invariant across
all reference frames.) In other words: such equation of privacy to physical
powerlessness presents feelings and perceptualities as unphysical ostensions,
unconstituted away of some particular reference frame —like virtual images in
the "depths" of a mirror— but improperly attributing such
"fixation" to lack of causal efficacy for connecting them nomically.
This lack, had it been true, would indeed have prevented feelings and
perceptualities to causally foreordain what is to change when their observer
moves, thus affixing their describability to a single reference frame, in
partial coincidence with observations. (Yet, as feelings and perceptualities do
cause physical effects, their one-witnessedness must come from another physical
source.) That specious deficiency would have thus prevented exchanging observers
in that reference frame, whose particularity should thus have become secluded
privacy. Wherefore the intrinsic pith of the "qualia" conception is to
pretend that all observations in physics are observations of extramental
position, and privacy foreign to physics.
5.
Chr. Jakob, Curso de neurobiología - Año lectivo 1900, Hospicio de las
Mercedes (Buenos Aires). The
course was summarized in: La Semana Médica vol. VII. Dates: 28 June 1900, pp.
325-327; 12 July 1900, pp. 354-358; 19 July 1900, pp. 363-366; 9 Aug. 1900, pp.
403-408; 30 Aug. 1900, pp. 439-444; 20 Sept. 1900, pp. 479-481; and 8 Nov. 1900,
pp. 589-590.
6.
Albeit the British Medical Journal published two communications reporting the
discovery of the brain oscillations of electric potential today called
electroencephalographic, the Northern hemisphere learning neglected it for at
least fifteen years, except for occassional citations of Caton’s name in lists
of experimental reseachers without any comment (e. g., that by G. Sergi, La
psychologie psychologique – édit. francaise, Alcan, Paris, 1888, p. 139).
Un
descubrimiento fundamental de Christofredo Jakob (1911): No existe corteza
asociativa.
A
fundamental discovery of Christfried Jakob (1911): The association cortex
nowhere exists.
5.El
descubrimiento de la Doppelrinde:
"Ueber
die Ubiquität der senso-motorischen Doppelfunktion der Hirnrinde als Grundlage
einer neuen biologischen Auffassung des kortikalen Seelenorgans"
Citation:
Lecture of September 26, 1911 (Munich); Münchener Medizinische Wochenschriff 9,
1912.
"Von
den Resultaten seien hier folgende resumiert: I. Alle Regionen der menschlichen
und tierischen Hirnrinde ohne Ausnahme sind rezeptorisch tätig, also sensitiver
Natur (eigenartig ist nur die Stellung der Ammonsformation, des ältesten
Rindenbezirkes) . . . II. Der Hauptanteil dieser sensiblen Strahlungen endet in
der kortikalen Aussenschicht (Aussenschicht = Stratum zonale, kleine, mittlere
und grössere äussere Pyramiden + Körnerschicht /Stratum intermedium/). . . .
III. Die Innenschicht der Rinde ist effektorisch tätig (motorisch), auch sie
existiert überall. (Innenschicht = tiefe, grosse und mittlere Pyramiden, tiefe
kleiner und polymorphzellige Elemente). . . . IV. Beide Fundamentalschichten
haben bei den Saügern bis zum Menschen übereinstimmend einen doppelten
Ursprung (monophyletisches Verhalten) und auch bei verschiedenen
Vertebratenklassen (Reptilienarten insbesondere) ist ähnliches zu konstatieren.
Dagegen gehört der Amphibientyp nicht dazu, mit einiger Ausnahme der
Gymnophionen, welch letztere aber nach unseren Untersuchungen geradezu den
Fundamentaltypus der Entwicklung des höheren Kortexapparates repräsentieren.
Unsere vergleichend kortexhistologischen Studien lehrten uns nun, dass die
beiden funktionell verschiedenen kortikalen Fundamentalschichten einen
getrennten Ursprung haben: die rezeptorische Aussenschicht entstammt dem
Riechhirn (einem sensiblen Hirnteil), die effektorische Innenschicht dem Corpus
striatum (einem alten, motorischen Zentral ganglion). Trotz des doppelten
Ursprungs gelangt aber die Gesamtrinde, je höher der Hirntyp sich entwickelt
hat /,/ zu einer um so innigeren Vereinigung beider Schichten und bei den Säugern
führt dies infolge der Ausbildung von weitverzweigten zellulären
Protoplasmafortsätzen und Kollateralen der Achsenzylinder einerseits und des
Auftretens massenhafter Binnenzellen und Zwischenschichtszellen andererseits zu
einer förmlichen sekundären Verschmelzung der in der Anlage getrennten
Rindenfundamentalschichten; ein Prinzip, das insbesondere die Primaten- und
somit auch die menschliche Rinde auszeichnet. V. Eine weder rezeptorische noch
effektorische Rinde (= "Assoziationsrinde") existiert nirgends . . .
Auf die Bedeutung dieser gänzlich neuen Anschauungen von dem Wesen und Wirken
unseres Seelenorgans . . . gedenken wir in Bälde zurückzukommen. Hier möchten
wir nur darauf hinweisen, dass diese aus der modernen biologischen
Gehirnforschung hervorgegangenen Ergebnisse sich in manchem eng mit Anschauungen
der neueren Philosophie (vergl. Wundts Apperzeptionstheorie, der Lehre vom
Unterbewussten, etc.) berühren, dass sich somit die Ergebnisse der
Seelenforschung mit denen der Gehirnforschung nicht mehr, wie bisher, in
schroffem Gegensatze befinden, möchten wir als ein besonders bedeutungsvolles
Symptom für die Zukunft der Rindenbiologie hervorheben".
Tomado
de:
http://electroneubio.secyt.gov.ar/general.htm
Enviado por admin
Contactar http://electroneubio.secyt.gov.ar/general.htm
Código ISPN de la Publicación: EplupuVVZkgddOYoVy
Publicado Saturday 8 de May de 2004
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