[Microstructure of fossil mammalian bones from the Rixdorfer Horizon of Weichsel-Kaltzeit at Niederlehme near Königs Wusterhausen (Brandengurg)]. / Zur Mikrostruktur fossiler Säugetierknochen aus dem Rixdorfer Horizont der Weichsel-Kaltzeit von Niederlehme bei Königs Wusterhausen (Brandenburg).

The structure is reported of bones of glacial-period mammals, which were found in 1973 to 1989 in gravel-sandy soil of the fossiliferous layer "Rixdorfer Horizont" at Niederlehme near Königs Wusterhausen. The findings, probably, date from one of the interstages of the glacial period "Weichsel-Kaltzeit" before the stage "Brandenburger Stadium". Their embedding took place more than 20,000 years ago. Changes of the deposit of bones and teeth from older sediments are not to exclude in the finding place Niederlehme. In the collection of findings with 102 skeletal parts are to define following species: Mammuthus primigenius, Coelodonta antiquitatis, Equus sp., Bison priscus, Megalocerus giganteus, Cervus elaphus, Rangifer tarandus and Canis lupus. A trajectorial direction of the trabecula in the substantia spongiosa is evident. There are also specific channels of blood vessels with different diameters. This channels have completely closed bone-wall (with a central venous sinus of diameter 5 to 10 mm) or in little vessels (diameter 1 to 3 mm), we have found many apertures to the rooms of the substantia spongiosa. The microscopical investigation of bones of Mammuthus primigenius has shown Havers' channels and perforating channels, Havers' systems and lacunae osseae.

[Development of telencephalon in Agapornis roseicollis Vieillot (Psittacidae) and its relationship to the evolution of the telencephalon in vertebrates]. / Die Entwicklung des Telencephalons von Agapornis roseicollis Vieillot (Psittacidae) und deren Beziehung zur Evolution des Telencephalons der Vertebraten.

1. The cerebral anlage of Agapornis roseicollis was investigated in serially cut slices during the developmental stages before hatching (day 3-day 20) by light microscopical quantitative and qualitative methods. 2. During earlier stages of development, the brain anlage is divided in three dorsally and four ventrally situated, longitudinally oriented matrix zones (D1-D3, V1-V4 according to Kuhlenbeck). In this developing system, mainly the lateral part of the telencephalic wall including its dorsal extension is considered to establish special importance for the further ontogenetic development. 3. The quite simple structure of the epistriatum in Reptils occurs as the neo-hyperstriatum-complex in Birds; likewise, deriving from the neocortex primitivus in Reptils, in Mammalia this part obviously develops to the more and more expanding neocortex as can be followed from lower mammalia species up to the highly developed Primates. According to the first main criterion of Remane, the homology of these parts of the brain in different vertebrates is most evident because these brain parts occupy exactly the same position in the brain anlage of early embryonal stages. 4. In Reptils, the neocortex primitivus appears as the last during ontogenetic development. Likewise in Birds, the neohyperstriatum-complex that is homologeous to the neocortex in Mammalia, differentiates during the final stages. These facts again emphasize the homology of these structures. 5. Further evidence for homology is obtained by the observation that in Agapornides the primordium of the neo-hyperstriatumcomplex contains migrating matrix cells columns, which also in Mammalia arrange into the same manner. Moreover, the transient and heterochronuous occurrence of cell layers at the outer surface of the brain anlage reminds to the development of palaeocortex and neocortex in Reptils and Mammalia. 6. From the point of view of evolution biology, the process of the progressive evolution is considered to be based on the step by step addition of tiny new structure-function-units to the already present morphology going along with a full structural and functional integration of the added, thus to achive the new quality. This so-called "Additive Morphogenesis" was effective during millions of years, consisting of such microevolutionary processes, and finally caused the "Gestaltungswandel", the ever changing evolving variety of bodily forms (and functions) that is recapitulated during individual species ontogenesis.

[The effect of conditioning on the ultrastructural distribution of synaptic vesicles in the hippocampus of the rat]. / Der Einfluss der Konditionierung auf die ultrastrukturelle Verteilung der synaptischen Vesikel im Hippocampus der Ratte.

In three months old male Wistar-rats the influence of conditioning (brightness discrimination reaction) on the number and distribution of vesicles of the synapses in the stratum radiatum (CA 3) of the hippocampus were investigated. A total of 15 rats (5 trained rats, 5 passive and 5 active controls) were studied by the aid of electron microscopic and morphometric methods. The number of synaptic vesicles was evaluated for the passive controls by 27 vesicles per synaptic area. In the CA 3-region 70 minutes after training the calculation of the number of synaptic vesicles revealed a significant decrease in comparison with passive and active controls (16 and 32 vesicles per synaptic area, respectively; significant difference at p less than 0.05). The volume of the synaptic vesicles was reduced for the trained rats by 20-25% in comparison with controls. The morphological results after training could be correlated with the changes of the Ach fractions, and seem to be of great significance at the initial stages of memory formation.

Electron microscopic and morphometric studies on synaptic plasticity in the hippocampus of the rat following conditioning.

1. In 40 three months old Wistar rats (16 trained animals, 14 active controls, 10 passive controls) the influence of learning (brightness discrimination) on the number of electronmicroscopically detectable synapses per area neuropil was studied in the stratum radiatum (CA 1) of the hippocampus. 2. 70 minutes after completion of training, the mean number of synapses has significantly increased as compared to active controls (trained animals 14.26 +/- 2.95 synapses/25 micrometer2; active controls 10.23 +/- 2.80 synapses/25 micrometer2; p less than 0.001). 3. 24 hours after training this increase in trained animals still persisted (trained animals 14.15 +/- 2.60, active controls 11.39 +/- 2.87 synapses/25 micrometer2; p less tha 0.001). 4. 14 days after training, the number of synapses has decreased considerably, but was nevertheless significantly higher than in the active controls (trained animals 12.49 +/- 2.76, active controls 11.45 +/- 3.10; p less than 0.001). 5. The results are discussed with regard to their significance to the different stages of memory formation in the CNS.

[The effect of orotic acid and orotic acid derivatives on the in vitro differentiation of hippocampus neurons-morphometric and electron microscopic studies of ribosomes]. / Uber den Einfluss von Orotsäure und Orotsäurederivaten auf die invitro-Differenzierung von Hippocampusneuronen--morphometrische und elektronenmikroskopische Untersuchungen über Ribosomen.

1. By means of electron microscopic and quantitative methods at the explantate cultures of the fetal hippocampus in vitro the influence of the orotic acid, sodium orotate and methylglucamine orotate on the neurogenesis was investigated. 2. After three days of the in vitro cultivation the neuroblasts influenced by these drugs show a smaller respectively not different degree of differentiation compared to the controls. 3. Under the influence of the orotic acid and of its derivatives the neurogenesis is significantly stimulated. The drugs produce a significant increase of the membrane-bound ribosomes and polysomes. The total number of ribosomes increases following the application of orotic acid by 20%, of sodium-orotate by 48% and of methylglucamine-orotate by 23% compared to the controls (alpha = 0,1%). 4. Sodium-orotate shows with reference to the neuronal development the clearest stimulatory effect. After 20 days in vitro the total number of ribosomes is by 60% higher at the treated cultures than in the controls. 5. The results might suggest, that an enlarged supply of the pyrimidine nucleotide via a raising of the RNA- and the protein synthesis might stimulate the development of the neuroblasts even under the in vitro conditions.

[Effects of brain extract and hydrolysate on nerve tissue in vitro]. / Uber die Wirkung von Hirnextrakt und -hydrolysat auf das Nervengewebe unter In-vitro-Bedingungen

Explants of PNS and CNS of chick embryos or fetal rats were cultivated and brainhydrolysat cerebrolysin or a synthetic aminoacidsolution or a brain extrakt was applied to the cultures. Cerebrolysin exercised in vitro an effect, which is related to charge only trifling. The cerebrolysin effect is essential related to the concentration/medium. High concentration of cerebrolysin decreases the growth of nerve fibers. Migration of non-neuronal cells increases. A stimulation of nerve fibers growth resembling to NGF was not seen. The density of cells or number of cells/volume unit, rate of mitosis and phases of mitotic non-neuronal cells is changed by cerebrolysin. The effect of cerebrolysin in vitro is compared to the tested aminoacidsolution and brainextract resembling. NGF may be important selectiv for stimulation of the activity of sympathetic and sensoric ganglia. Brainextract and brainhydrolysat and aminoacidsolution influenced in vitro PNS- and CNS-tissue cultures.