JOURNAL OF THE NEUROLOGICAL SCIENCES

Society Proceedings

397

PROCEEDINGS OF THE i N T E R N A T I O N A L R O U N D TABLE CONFERENCE HELD U N D E R THE AUSPICES OF THE INTERNATIONAL SOCIETY OF

NEUROVEGETATIVE RESEARCH (Dutch Institute for Brain Research, Amsterdam, July 10 13, 1963)

A round table conference was held at the Dutch Institute for Brain Research from July 10th-13th, 1963, dedicated to a through study of the Present State o f Research upon the Epiphysis.

This meeting was orgart;zed by Prof. Ariens Kappers, Director of the Institute for Brain Research, in collaboration with 75 scientists who came from all parts of the world.

The conference was held in the splendid building of the Dutch Academy of Sciences, the Trippenhuis. Prof. Carmen Coronini-Cronberg, Honorary-President, was unable to open the session on account of illness. In the absence of Prof. Coronini, Prof. Adam was the sole Aus- trian representative. The scientific outcome of these sessions was excellent and Prof. Adam declared he had drawn the utmost profit from it. Wednesday July lOth

The meeting was opened by Prof. Ariens Kappers.

Prof. A. Oksche (Kiel) was the first speaker. He made a suggestive report on the researches carried out in the field of the epiphysis during the past 100 years. He particularly emphasized the recent discoveries on the microscopical struc- ture and the histochemistry of the cellular ele- ments of the amphibian epipbysis. It has al- ready been possible to discover in those animals important data concerning the function of the epiphysis, particularly resulting from the study of the pineo-frontal vesicle (Vide Dodt and Heerdt on the chromatic and achromatic reac- tions of the visual elements within the frontal organ).

Prof. J. C. van de Kamer (University of Utrecht) gave an account of the synthesis of the histological structure and cytology of the pineal organ of fishes, amphibians and reptiles. Data resulting from electron microscopy and the cyto- chemistry of the receptors were fully reported.

Dr. Quay (University of California) described the histology and cytology of the pineal organ of birds and mammals. Study of the mammalian epiphysis is particularly arduous owing to the fact that the parenchymal elements of the mam- malian epiphysis are difficult to identify among other cellular types. A more thorough study of these cellular types is necessary.

Dr. Altner (Zoological Institute of the Univer- sity of Munich) had studied the sub-commis-

sural organ in fishes and the irrigation of tbis organ with neurosecretory fibres in the hypo- physo-hypothalamic area. He emphasized the differences between the secretions of the sub- commissural organ and the neural secretions by utilizing the method of extinction-phenomenon with methylene blue.

Dr. Holmgren (Zoological Institute of the University of Uppsala) brought some prelimin- ary data on the ontogenesis of the pineal and parapineal organs of Salvinellus fontinalis un Teleosteen. Holmgren dealt witb the question of the differences between the blastema of the pineal and parapineal organs.

The contribution of Dr. Lierse (Institute of Anatomy of Hamburg) was based on the vas- cularisation of the epiphysis in reptiles. Whereas elsewhere in the brain, vascularisation is assured by vascular coupling, the conditions are quite different in the epiphysis. Vascularisation here is assured by way of a major branch which then gives rise to segmental lateral branches.

The structural aspect based on electro micro- scopy, explained in the report of Prof. Horst- mann (Hamburg), Dr. VaupeI-Harnack and Dr. Oksche (Kiel), was discussed by Dr. Kelly (Seattle). In the foreground of these discussions was the question of the microscopical structure of the so-called receptor cells which offer anal- ogies with the retinal elements and medullated fibres.

Dr. Steyn (Windhoek) gave the result of his researches on desert hedgehogs in South-West Africa. He showed that the hypophysis and particularly the parietal organ of this animal constitute the receptor of a mechanism for the regularization of respiration. This renders plausible the idea that the parietal organ serves to control heat and dryness. The microscopical stlucture of the mammalian epJphysis formed the subject of several free communications of the second day. Thursday July 11th

Drs. Wartenberg and Gusek (Hamburg) dis- cussed the electro-optic structure and the epi- physis of the guinea-pig. In the following reports, we also found electromicroscopical data, es- pecially on the innervation of the pineal organ of the rat, presented by Dr. Wolfe (Boston). It appears from these communications that there

J. neurol. Sci. (1964) 1 : 397-404

398 SOCIETY PROCEEDINGS

are very great difficulties concerning the inter- pretation of the different cellular types within tbe mammalian epiphysis. Wolfe was able to demonstrate a rough surfaced endoplasmic reticulum in some cells. During the discussion, Dr. Adam stressed the fact that this type of cell resembles the parenchymatous cells of the sub- fornical or terminal organ in apes. These indica- tions are particularly important, sirce we know but little about the origin of the parenchymatous ceils.

Prof. Ariens Kappers reported fully on the innervation of the pineal organ in various verte- brates. A special interest should be shown in the autonomous innervation of the organ owing to the fact that it throws light upon the speciali- sation of its function in the mammalians. The fibres contain adrenergic vesicles which, after adrenalin has been administrated, increase in volume and density. It is possible that these nerve endings have to do with the production of serotonin, and that they have also some relation- ship with the conversion-products called melatonin. Serotonin may be freed from the nerve-fibres by reserpin, but not from the pineal cells.

Dr. Scharenberg (Ann Arbor) showed beauti- ful silver carbonate preparations of the epi- physical nerves and made a standardization test of the nerve fibres based upon such datg.

Dr. Pellegrino (Iraldi) reported the result of her investigations made with Dr. de Robertis and Dr. L. M. Zieher on nerve-endings of the pineal organ after various pharmacological sub- stances had been administered. The granular contents of the nerve-vesicles are modified after administration of reserpine.

Dr. L. Arvy gave an interesting communica- tion upon the histochemical enzymes which can be disclosed in the Artiodactylan epiphysis. Study of phosphates shows that we are in the presence of two types of vessels. The pineal cells show a high content of succinodehydrogenase and leucyl-fl-naphthylesterase.

Dr. Prop (Groningen) very clearly explained the composition of the lipids in the pineal organ of mammals. He gave particular attention to the differentiation between the lipids. The tri- glycerides and phospholipids containing cholin are certainly present; other phospholipids are probably also present. He has also been able to establish that in addition to lipase there exists a non-specific esterase which plays an important part in the metabolism of the free lipids of the epiphysis.

Dr. Owman (Lund) showed, by means of an interesting fluorescence-technique, that sero- tonin and melatonin are also present in situ in the mammalian epiphysis.

During the evening the various communica-

tions were thoroughly discussed in the smoking- room. All participants had the opportunity of discussing among themselves the different prob- lems evoked during the sessions.

Friday July 12th

Physiologists and biochemists took the floor. Prof. Thielblot (Clermont-Ferrand) reported on the facts known at present concerning the phys- iology of the epiphysis.

Dr. Bagnar (Tucson, USA) mentioned the interesting effects of discolouration of the am- phibian larvae after extirpation of the hypo- physis and administration of melatonin. Dr. Novales (Evaston, USA)discussed the same prob- lemand especially the antagonist approach between melatonin and other in vitro agencies.

Dr. Wurtmann presented a communication upon the research he has been carrying out in collaboration with Drs. Axelrod and Chu, the purpose of which was to show the relationship between formation, metabolism and biological signification of the epiphysis substance of the melatonin type in mammals. It should be re- called that they have been able to show the existence of a proper transferase which might be responsible for the conversion of serotonin into melatonin, the hydroxyndol-o-methyl- transferase. This substance is found in the epi- physis and in large amounts in birds.

The hormonal action on the epiphysis lipids was explored by Dr. Zeens (Groningen), and Dr. Roth (Boston) reported on the alteration of the epiphysis in rats during puberty.

As regards the pathology of the epiphysis, Prof. Frauchiger (Bern) suggested a new notion to justify the birth of the epiphysis in mammals. In his opinion, the epiphysis, as well as the hypo- physis, in mammals may develop from a neural part and from a part coming from the outside and from above.

Dr. Walter (Munich) took up a definite atti- tude regarding those researches. Unfortunately, preparations could not be shown, which should have brought more clarity to this question. In this respect, the calf embryos, studied by Dr. Walter, might have given valuable indications.

The whole of the Congress was very welt organiz- ed. Owing to the small number of participants, it was possible to establish personal contacts, and the topics, which were strictly defined, gave rise to fruitful discussions. It is hoped that the World Federation of Neurology might continue to organize such small meetings on topical ques- tions in neuro-histology, neurobiology and neuropathology. The scientific results of such meetings are generally excellent.

H. ADAM

J. neurol. Sci. (1964) 1:397-404