Topistic brain research

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Topistische brain research is called in the neurophysiology to describe the brain and to define the qualitative special functions on the principle of the place since the early 20th century attempts regions within the macro- and microscopic blueprint self-organization feature. The description of such special functions is supported by structural features of cyto- , myelo- , angio- , fibrillo- and glio-architectural type.

history

As the beginning of the topistic modes of representation, one can see the assumption of René Descartes (1596–1650), who accepted the pineal gland in the brain as the “only unpaired organ” as the physically and locally responsible authority for the interaction of body and soul ( body-soul problem ). He considered consciousness to be the psychological and subjectively essential substance (res cogitans), all other functions as automatic bodily-material processes (res extensa). By demanding such a connection, he created the prerequisites for a more humanistic psychology or consciousness psychology on the one hand, and for an anatomically oriented science on the other. This corresponded to the scientifically oriented research of his time.

Topistic brain research and somatotopics

Representation of a cortical homunculus according to Wilder Penfield (1950). Both the motor cortex shown and the sensory cortex are organized according to the dwarf figure shown (sensorimotor region). The sketch of the Homunculus represents a topistic illustration in which the zones of the hand, mouth and lips are relatively more pronounced due to functional features, cf. also Anaklise .

The comprehensive meaning of the draft of a topistic brain research already results from the terminology of somatotopics, which goes back to Wilder Penfield .

This goes back to the concrete anatomical organization and the summary processing of neural impulses that emanate from the "skin senses". (See also the sense of touch including sensitivity ).

The description of similar organizational principles with other sensory modalities , however, requires a different linguistic regulation and thus also certain terminology.

By increasing the surface area one is Gyrusbildung stimulated. It enables increased cephalization . Different sensory physiological "topias" such as B. Tonotopy and retinotopy require different names and at the same time general terms in order to describe the common organizational principles in the area of ​​these sensory modalities, see also Somatotopia , Chap. Origin and development of the term. Such a clarification is z. B. the necessary distinction between sensitive and sensory.

Sensitive and sensory

Only in the brain centers are afferent sense tracks as sensory referred. The term sensory refers to qualities and nerve tracts that affect the sensorium and are therefore capable of consciousness .

At the level of the spinal cord , afferent pathways, which originate from the skin as a sensory organ, are referred to as sensitive and not as sensory pathways, insofar as they are e.g. B. trigger reflexes or autonomous stimulus responses on this level, but do not provoke any conscious reactions. These sensitive pathways determine the sensitivity that is typical of the spinal cord , which is divided into depth and surface sensitivity according to the position and then differentiated into epicritical and protopathic sensitivity with regard to the discrimination performance .

Integrative service of the CNS

Squid nervous system
(author unknown, 1876)

The in the previous chap. The term “ brain centers ” used in a sensitive and sensory way logically includes a conceptual clarification and distinction between the central nervous system (CNS) and the peripheral nervous system .

These topistic distinctions, not only conceptual, but also due to the anatomy of the brain and spinal cord, are also useful due to the hierarchical structure of the CNS. The CNS itself is divided into higher and lower centers.

This results from the structural principle of the development of the CNS and its stimulus-conducting apparatus from the “periphery” or from the ectoderm . This is shown by the biological development series of a not yet centralized nervous system indicated in the figure using the example of the squid . Jakob von Uexküll called the nervous system of sea ​​urchins a “reflex republic” , cf. also centralism .

The term “somatotopics”, which was “newly coined” from around 1940–1950, had and has achieved far-reaching significance for understanding how the brain works. The point-to-point arrangement of body representations (example: homunculus ), which maintains a largely structural or physical unit, fulfills, as is well known, higher-level integrative functions within the CNS.

Especially in neurophysiology, but also in psychology and psychosomatic medicine , the concept of integration plays an important role in understanding the various levels or degrees of integration.

In the case of somatotopia, the different degrees of integration of the processing of afferent neuronal impulses at the level of the spinal cord and the brain must first be taken into account. For disorders of integration at the level of the limbic system or the formatio reticularis , the term organ neurosis or functional syndromes has become established.

In this integrative view, not only a hierarchical structure can be determined, but also a somatotopic structure according to antagonistic functions. This means e.g. B. that in the area of ​​the cerebral cortex the stretching and internal rolling of the foot as well as the plantar flexion of the foot are “topically” close together. The same applies to B. to for flexion and extension of the thumb, index finger, elbow joint, etc. etc. etc.

Generic term of the topic

The question arises whether the term “topic” appears useful as a generic term for the various characteristics of topical representations of different sensory modalities .

The incomplete concept of somatotopia for the skin senses, which is based solely on the sense of touch, and the uniform functional principle of topical integration in the CNS that is clarified with it, also requires a generic term if it is e.g. B. is about other similar functional principles in other sensory performances ( sensory integration ).

In the case of “somatotopic”, the term “topic” is not a simple “localization”, but rather diverse topical modes of representation within the CNS and their integrative interaction.

In this case one can also speak of a transferred meaning for the term component “topic” or of a topic in different stages or degrees.

The term topical is also important in psychology . Here, too, it is used partly in a figurative sense, partly on the assumption that specific, strictly localized research results can still result.

In this figurative sense, “Topik” appears to be appropriate above all for the various neuronal processes in the sense of an “anatomical Topic”. In the English language the term “place theory” is used in general terms. But the term somatotopia is often used in scientific literature beyond the pure representations of the sense of touch and its various qualities as a generalization for the specific topical structure in the CNS and as a generic term for the other sensory modalities.

Two groups of examples

The functional principle in the area of ​​the CNS that can be recognized in the case of the somatotopic is not limited to the application within a sensory-motor system. Rather, this is just one of a large number of feedback systems not only in the nervous system. The different somatotopic centers within the

  • Cerebrum and cerebellum
  • Cortex and thalamus
  • Cortex and Limbic System

require further integration of the various functional groups that exist between the structures mentioned. Also in the

somatotopic aspects play an important role. One of its principles is the thesis, which goes back to Plato and Aristotle , that “the whole is more than the sum of the parts”. According to Francis Galton (1822–1911), this integration task is important for distinguishing between conscious and unconscious thought activities.

Neural Networks

Recently, this integration of the nervous system has been made possible by network simulations such as B. Kohonen networks have been researched and made understandable. The structure of such a network according to very specific or very different characteristics and not just according to physical design principles plays a decisive role. The physical-shape structure in the case of somatotopia is only one of the examples for a design of Kohonen cards . This is generally done according to the principles of similarity, frequency and importance (relevance).

Topics and localization

"Topic" differs from " localization " in that the topical view is based on the interaction of all structures involved, both in the perception of the "sensory archetype" and in the representation of different "central images".

“Localization” always means only one specific feature at a specific point in the CNS.

The localization concept is important for anatomy in a descriptive and dissecting way of individual structures and features, the topical concept for the functional understanding of the relationships between all the anatomical structures involved.

Brain research and brain mythology

The allegations raised against Karl Kleist (1879–1960), such as the “brain mythology” or the “reflex mythology” against Iwan Petrowitsch Pawlow (1849–1936), call for a standardization of the language, since such allegations come from different camps, each of which the The language regulation of the other cannot be accepted. Such standardization can only be achieved through overarching models. The topic offers a promising approach to this.

It took militant efforts for neurology to be recognized as an academic subject and a specialty. The main focus here was the methodological independence of neurology and its replacement from internal medicine. The Basel neurologist Robert Bing (1878–1956) achieved this success, at least in Switzerland. The played topical diagnosis a crucial role. Bing can be seen as one of its pioneers.

See also

Individual evidence

  1. a b c Alfred Benninghoff u. a .: Textbook of human anatomy. Shown with preference given to functional relationships. Volume 3: Nervous System, Skin and Sensory Organs . Urban and Schwarzenberg, Munich 1964; (a + b) to chap. “The construction of the cerebral cortex”: pp. 226–228; (c) Re. "Development of the stimulus-conducting apparatus": p. 107.
  2. Peter R. Hofstätter (Ed.): Psychology . The Fischer Lexicon, Fischer-Taschenbuch, Frankfurt a. M. 1972, ISBN 3-436-01159-2 ; P. 206 f. to lemma “body-soul problem” and stw. “res cogitans and res extensa”.
  3. ^ Wilhelm Karl Arnold et al. (Ed.): Lexicon of Psychology . Bechtermünz, Augsburg 1996, ISBN 3-86047-508-8 ; to Lex.-Lemma: "Zentralnervensystem", Stw. hierarchical structure: Col. 2686 f.
  4. a b c Thure von Uexküll : Basic questions of psychosomatic medicine. Rowohlt Taschenbuch, Reinbek bei Hamburg 1963, (a) pp. 97 f., 149, 219 ff .; For information on “integration space”, see pages 128, 131, 224 f., 229 ff., 234 f. (b) p. 165 ff.
  5. Fritz Hartmann et al. (Ed.): The Fischer Lexicon. Medicine III. Fischer Library, Frankfurt 1959; to the district “Emotion and Emotion Processing” p. 152.
  6. Philip G. Zimbardo , Richard J. Gerrig: Psychology . Pearson, Hallbergmoos near Munich 2008, ISBN 978-3-8273-7275-8 ; Regarding the “Physiology of Emotions”: p. 459 ff.
  7. ^ Leonard Landois , R. Rosemann: Physiologie des Menschen. 26th edition. Urban & Schwarzenberg, Munich 1950, quoted from the illustration in: Roche Scientific Service: From Emotion to Lesion . Hoffmann-La Roche, Grenzach Baden 1968, p. 13
  8. a b Peter Duus: Neurological-topical diagnostics. Anatomy, physiology, clinic . 5th edition. Georg Thieme Verlag, Stuttgart 1990, ISBN 3-13-535805-4 , (a) p. 112. There it says in the description of retinotopic facts before and after the crossing of the fibers of the optic nerve in the optic chiasm : “Despite the partial crossing, is maintain a strict somatotopic point-to-point arrangement right into the visual cortex. ”- The term retinotopy is nevertheless used elsewhere, namely on p. 367 and 373; (b) p. 362
  9. Francis Galton : Inquieries into human faculty and its developement . MacMillan, London 1883, pp. 202 f.
  10. Manfred Spitzer : Spirit in the net , models for learning, thinking and acting. Spektrum Akademischer Verlag Heidelberg 1996, ISBN 3-8274-0109-7 , p. 116
  11. Marco Mumenthaler : Neurology in the training of the Swiss doctor. In: Switzerland. Arch. Neurol. Psychiatr. , 2008, 159, pp. 265-256