Sexual center

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Hypothalamus / pituitary / gonadal control circuit

As sexual center areas are the central nervous system refers to the control of sexuality serve. The concept of an independent, delimited sexual center has been neurophysiologically refuted. Rather, different areas of the brain and spinal cord are involved in the control of sexual functions, which also have diverse connections to other brain regions.

Sex centers in the brain

Different areas in the brain are involved in controlling sexual functions. These are primarily the limbic system , the hypothalamus and the praeoptica region .

In male individuals, the amygdala , the nucleus accumbens, and the sexually dimorphic nucleus in the praeoptica region seem to play a role in controlling sexual behavior. Here, many find testosterone - receptors . Destroying the almond kernel leads to hypersexuality ; if only the medial part is destroyed, sexual activity will decrease. These two centers also receive afferents from the Jacobson organ in animals . In female animals, the ventromedial hypothalamic nucleus ( nucleus ventromedialis ) in particular seems to control sexual activity. It possesses numerous estrogen and progesterone receptors , its stimulation promotes sexual activity in rats, the destruction leads to the abolition of these.

In the narrower sense, the eminentia mediana in the hypothalamus is called the sexual center. This is where the gonadoliberin is formed , which controls the release of the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the pituitary gland , i.e. the endocrine center of gonadal function. Gonadoliberin is transported to the pituitary gland via the portal vein system of the pituitary gland.

Sex centers in the spinal cord

In the spinal cord there are two sex centers. The psychogenic spinal sexual center is located in the spinal cord segments Th11 – L2, ie in the lower thoracic and upper lumbar cord. The reflexogenic spinal sexual center lies in the cruciate medulla (S2 – S4).

History of exploration

The anatomist's point of view

Individual nuclei of the hypothalamus had already been described in the 19th century, e.g. B. the ganglion opticum basale in the diencephalon , which Theodor Meynert first described in his monograph On the Brains of Mammals . Sigmund Freud, who did neurological and brain anatomical work in Meynert's laboratory at the end of the 19th century, formulated a preliminary “chemical theory” of sexuality. Inspired by Meynert, Auguste-Henri Forel researched the histology and topography of what he called the subthalamic region of the brain at the time . Michael (Mihály) von Lenhossek differentiated the first nuclei in the diencephalon in 1887, but systematic research into the human hypothalamus did not begin until 1910 with Edward F. Malone , who applied Jacobsohn's histopathological interpretation and Korbinian Brodmann's cytoarchitectonic structure to the diencephalon. The central gray cave in the vicinity of the Tuber cinereum was still described by Malone in 1910 as homogeneous and indivisible.

Brodmann's neurobiological laboratory

The pathologist's point of view

As early as 1904, the pathological anatomist Jakob Erdheim , based on autopsy findings in patients with dystrophia adiposogenitalis, described a center at the base of the brain, a center in the hypothalamus that controls the adipose component of this syndrome. With regard to the genital center, which Erdheim also suspects in the hypothalamus, he makes no specific statements. Subsequently, but also before that, many clinical and pathological-anatomical findings are presented, all of which point to a center in the hypothalamus that is superior to the gonads.

The neurophysiologist's point of view

Neurophysiological experiments at that time support the anatomic-pathological concepts. If in the 1890s, for example by Friedrich Leopold Goltz, the seat of the sexual center was assumed to be within the brain, then more and more people come to localize it at the base cerebri. At the beginning of the century, Joseph Babinski and Alfred Fröhlich relocated the center to the anterior pituitary lobes. The posterior lobe of the pituitary gland was favored in 1910 by Bernhard Fischer-Wasels , head of the Senkenberg Institute of Pathology and Anatomy in Frankfurt am Main. Otto Marburg (27) believed in 1909 to have found a central gonadal organ in the pineal gland . Between 1909 and 1912, Johann Paul Karplus and Alois Kreidl then identified a center of the sympathetic nervous system at the base of the brain , which should lie in the rear part of the diencephalon.

Bernhard Aschner's experiments in 1912 not only confirmed Erdheim's vegetative center in the hypothalamus, but also a sympathetic center, as Karplus and Kreidl had already assumed. In addition, Aschner points to a trophic center at the base of the diencephalon. Aschner considered in 1912 that this would be a menstrual center. act. This has some influence on the female genital sphere . out. "Such trophic centers and pathways for the genital system should not only be found in the diencephalon, but downwards in the entire brain stem, in the medulla oblongata, in the cerebellum and finally also in the spinal cord". Aschner concludes that more precise localization and physiological research, e.g. For example, an extragenital “menstrual center” is an attractive task for the future. Aschner did not speak of a “genital center in the brain” (sexual center) until 1918. In Aschner's ideas from 1912, a control loop model as we know it today was of course still present unthinkable.

A paradigm shift did not take place, however, since Harvey Cushing's and Artur Biedl's authoritarian interventions turned the interest of the investigators towards the study of the pituitary function.

The synthesis of the endocrinologist

The midbrain was not increasingly considered until the 1930s. To assign Walter Schoeller and Gehrke 1933, Schoeller in 1932 and Adolf Butenandt 1934 on a possible localization of the sexual center in the midbrain out. A justification for this can be derived from the experiments Hohlweg and Junkmanns with parasympatholytics . According to the opinion of the time, the center of the parasympathetic nervous system was located in the midbrain, while the hypothalamus mainly regulates the function of the sympathetic nervous system.

Two years earlier, in 1930, the Hungarian Grigore T. Popa and the Australian Una Lucy Fielding described a venous connection between the anterior pituitary gland and the hypothalamus. They saw more than a dozen veins run from the tuberosity of the pituitary gland into the funnel lobe and from there into the cinereum tuberosity. However, Popa and Fielding incorrectly interpret the direction of flow as centripetal, running from the anterior pituitary to the hypothalamus.

It was not until 20 years after Aschner's first description of the sexual center in the diencephalon that Walter Hohlweg and Karl Junkmann from the main laboratory of Schering-Kahlbaum AG in Berlin were able to demonstrate experimentally in 1932 that the gonadotropic function of the pituitary gland is controlled by a center in the central nervous system (CNS). Hans H. Simmer described the related endocrinological discourse of the 1930s. Negative feedback between the gonads ( estrogens ) and the pituitary was discussed controversially. The foundation of the endocrine interaction of gonadal functions with the central nervous system was laid on the basis of clinical observations, pathological anatomical findings and animal experiments.

Control loops (feedback)

In 1932, Hohlweg and Junkmann used a triangular diagram in which the relationships between the gonad (ovary), pituitary gland and central nervous system (CNS) were visualized. Reduction or failure of the gonad hormone increases the pituitary hormone production via the sexual center in the CNS, while satiety with sex hormone inhibits pituitary secretion in the same way. The connection between the central nervous system and the pituitary gland, Hohlweg and Junkmann 1932, was conceived as a centrifugal neural connection.

Endocrine CNS center

The leading role of the endocrine hypothalamus in this control loop was confirmed by the evidence that testes continue to secrete hormones after transplantation into other parts of the body as long as the pituitary gland is intact, whereas transplanted pituitary glands lose this ability.

Further reading on the history of the hypothalamus

  • Evelyn Anderson: Earlier ideas of hypothalamic function, including irrelevant concepts. In: Webb Haymaker, Evelyn Anderson, Walle Nauta (Eds.): The Hypothalamus. Charles C. Thomas, Springfield, Illinois 1969, pp. 1-12.
  • Evelyn Anderson, Webb Haymaker: Breakthroughs in hypothalamic and pituitary research. In: Progress in Brain Research. 41, Amsterdam 1974, pp. 1-60.
  • Marius Tausk: Brief endocrine history of the German-speaking peoples. In: J. Kracht, A. von zur Mühlen, PC Scriba (Ed.): Endocrinology Guide. Brühlsche Universitatsdruckerei, Gießen 1976, pp. 1–34.
  • Victor Cornelius Medvei: A History of Endocrinology . International Medical Publishers, Lancester / Boston / The Hague 1982.
  • Rudolf Pappenberger: Dependence of the gonadal function on the central nervous system. Clinical observations and animal experiments between 1850 and 1912 . Inaugural dissertation . Med. Fac. Of the Univ. Erlangen-Nuremberg 1985.
  • Hans H. Simmer: The beginnings of endocrinology. In: Allen G. Debus (Ed.): Medicine in Seventeenth Century England. A Symposium held at UCLA in honor of CDO'Malley. University of California Press, Berkeley / Los Angeles / London 1974, pp. 215-235.

Individual evidence

  1. ^ A b c Claus Buddeberg: Sexual Counseling: an introduction for doctors, psychotherapists and family counselors. 4th edition. Georg Thieme Verlag, 2005, ISBN 3-13-136574-9 .
  2. ↑ Helen Singer Kaplan: Sex Therapy for Disorders of Sexual Desire. 2nd Edition. Georg Thieme Verlag, 2006, ISBN 3-13-117972-4 .
  3. ↑ Thomas Köhler: Medicine for psychologists and psychotherapists: based on the license to practice medicine for psychological psychotherapists. 2nd Edition. Schattauer Verlag, 2010, ISBN 978-3-7945-2696-3 .
  4. ↑ Theodor Meynert: From the brains of mammals. In: S. Stricker (Hrsg.): Handbook of the doctrine of the tissues of humans and animals. 2 volumes. Engelmann, Leipzig 1872, pp. 694-754.
  5. ↑ Sigmund Freud: Three treatises on the theory of sex. 2nd Edition. Franz Deutike, Leipzig / Vienna 1910. (The first edition appeared in 1905)
  6. ↑ August Forel: Investigations into the hood region and its upper connections in the brains of humans and some mammals, with contributions to the methods of brain investigation. In: Archives for Psychiatry and Nervous Diseases. 7, Berlin 1877, pp. 393-495.
  7. ↑ Michael von Lenhossek: Observations on the human brain. In: Anatomischer Anzeiger. Centralblatt for the entire scientific anatomy 11, Jena 1887, pp. 450–461.
  8. ^ Edward F. Malone: On the nuclei of the human diencephalon in some mammals. In: Treatises of the Royal Prussian Academy of Sciences. Physical Mathematical Class. Attachment. Treatise 1. Berlin 1910, pp. 1–32.
  9. ↑ E. Malone, L. Jacobsohn-Lask: About the nuclei of the human diencephalon. Royal Academy of Sciences, Berlin 1910.
  10. ↑ L. Jacobsohn: About the nuclei of the human brain stem (Medulla oblongata, Pons and Pedunculus cerebri). In: Treatises of the Royal Prussian Academy of Sciences. Physical-Mathematical Class. Attachment. 1st treatise. Berlin 1910, pp. 1-70.
  11. ^ J. Erdheim: About pituitary duct tumors and brain cholestatome. In: Meeting reports of the Imperial Academy of Sciences. Mathematics and science class. (Vienna) 113, 1904, pp. 537-726.
  12. ↑ Friedrich Goltz: About the functions of the cerebrum . In: Archives for the entire physiology of humans and animals. (Bonn) 13, 1876, pp. 1-44.
  13. ^ Joseph Francois Felix Babinski: Tumeur du corps pituitaire sans acromegalie et avec arret de developpement des organes genitaux. In: Revue neurologique. (Paris) 8, 1900, pp. 531-533.
  14. ↑ Alfred Fröhlich: A case of tumor of the hypophysis cerebri without acromegaly. In: Wiener Klinische Rundschau. 15, 1901, pp. 883-886 and 906-908.
  15. ↑ Bernhard Fischer: Hypophysis, acromegaly and obesity . Bergmann, Wiesbaden 1910.
  16. ↑ Otto Marburg: For the knowledge of the normal and pathological histology of the pineal gland. Cerebral obesity. In: Works from the Neurological Institute (Institute for Anatomy and Physiology of the Central Nervous System) at the University of Vienna. (Leipzig, Vienna). 17, 1909, pp. 217-279.
  17. ^ Johann Paul Karplus, Alois Kreidl: Brain and Sympathicus. 1st communication. Diencephalon and cervical sympathetic nerve. In: Archives for the entire physiology of humans and animals. (Bonn) 129, 1909, pp. 138-144, 135; 1910, pp. 401-416, 143; 1912, pp. 109-127.
  18. ↑ Bernhard Aschner: Demonstration of dogs after extirpation of the pituitary gland (short communication). In: Wiener Klinische Wochenschrift. 22, 1909, pp. 1730-1732 .; Bernhard Aschner: About the sequelae after extirpation of the pituitary gland. In: Negotiations of the German Society for Surgery. (Berlin) 39, 1910, pp. 46-49 .; Bernhard Aschner: About the relationship between the pituitary gland and the genitals. In: Archives for Gynecology. (Berlin) 97, 1912, pp. 200-228.
  19. ↑ Bernhard Aschner: About the function of the pituitary gland. In: Archives for the entire physiology of humans and animals. (Bonn) 146, 1912, pp. 1-46.
  20. ↑ Bernhard Aschner: To the physiology of the diencephalon. In: Wiener Klinische Wochenschrift. 25, 1912, pp. 1042-1043.
  21. ↑ a b Bernhard Aschner: About the relationship between the pituitary gland and the genitals. In: Archives for Gynecology. (Berlin) 97, 1912, pp. 200-228, p. 218 and p. 224.
  22. ↑ Bernhard Aschner: The blood gland diseases of women and their relationship to gynecology and obstetrics. JF Bergmann, Wiesbaden 1918.
  23. ^ Harvey Cushing: The Pituitary Body and its Disorders . JB Lippincott, Philadelphia / London 1912.
  24. ^ Artur Biedl: Inner secretion. Their physiological foundations and their significance for pathology . Urban & Schwarzenberg, Berlin / Vienna 1910.
  25. ↑ Gehrke Schoeller: About inhibition factors and the mechanism of the effect of opposite sex sex hormones on the development of the gonads. In: Biochemical Journal . (Berlin) 264, 1933, pp. 352-356.
  26. ↑ Schoeller: Newer work on the hormone area. In: German Medical Weekly . (Leipzig) 58, 1932, pp. 1531-1534.
  27. ↑ Adolf Butenandt: Newer results in the field of sex hormones. In: Wiener Klinische Wochenschrift. 47, 1934, pp. 897-901 and pp. 934-936.
  28. ^ Gregor Popa, Una Fielding: The vascular link between the pituitary and the hypothalamus . In: The Lancet . (London) 219, 1930, pp. 238-240.
  29. ^ Gregor Popa, Una Fielding: A portal circulation from the pituitary to the hypothalamic region. In: Journal of Anatomy . 65, 1930, pp. 88-91.
  30. ^ W. Hohlweg: Regulatory centers of endocrine glands in the hypothalamus. In: Joseph Meites, Bernhard T. Donovan, Samuel M. Mc Cann (Eds.): Pioneers in Neuroendocrinology. Plenum Press, New York / London 1975, pp. 159-172 .; Walter Hohlweg: The discovery of the sexual center in the hypothalamus. In: Endocrinology Information. (Graefelfing) 6, 1982, pp. 138-144.
  31. ↑ H (ans) H. Simmer, J (ochen) Süß: On the early history of negative feedback from estrogens. The priority dispute between Dorothy Price and Walter Hohlweg. A contribution to the question of self-deception in scientific priority claims. In: Natal u. Frauenheilk. 53, H. 6, Thieme 1993, pp. 425-432.