Developmental changes of nerve growth factor and its mRNA in the rat hippocampus: Comparison with choline acetyltransferase

Previous experiments have demonstrated that in the septo-hippocampal system choline acetyltransferase (ChAT) is induced by nerve growth factor (NGF) (Gnahn et al. (1983) Dev. Brain Res. 9, 45-52) and that hippocampal NGF and mRNANGF levels are correlated with the density of cholinergic innervation (Korsching et al. (1985) EMBO J. 4, 1389-1393). In the present investigation we have compared the developmental changes of ChAT, NGF, and mRNANGF levels in this system. During the postnatal development of the hippocampus the time courses of NGF and ChAT were well correlated including the most rapid increase between P12 and P14. This increase in hippocampal NGF was preceded by a corresponding increase in mRNANGF. The developmental changes in hippocampal NGF levels were also closely reflected by corresponding changes in the septum. This, together with previous observations (Korsching et al., 1985) that the adult septum, in spite of relatively high NGF levels, does not contain measurable quantities of mRNANGF, suggests that the NGF levels in the septum are determined by the quantity of NGF transported retrogradely from the field of innervation rather than by local synthesis. During the prenatal period hippocampal NGF levels were relatively high, whereas the mRNANGF was below the level of detection. Since the ingrowth of septal fibers, and with that also the removal of NGF by retrograde transport, begins around birth, the relatively high prenatal NGF levels probably result from an accumulation produced by a small copy number of mRNANGF prior to the removal of NGF by retrograde axonal transport. It is concluded that the correlation of the developmental changes in NGF and mRNANGF with the ChAT activity in the hippocampus further supports the concept of a physiological role of NGF in the central nervous system.     

Ethanol production from xylose with a pyruvate-formate-lyase mutant of Klebsiella planticola carrying a pyruvate-decarboxylase gene from Zymomonas mobilis

Summary Grown anaerobically on d-xylose, Klebsiella planticola ATCC 33531 produced acetate, formate, lactate, CO₂ and ethanol as major end-products. A Mu-insertion mutant which lacked pyruvate-formate-lyase showed among its fermentation products more than 70% d-lactate with residual acetate, 2,3-butanediol, and traces of ethanol, formate, and CO₂. After the introduction of a plasmid carrying the gene for the enzyme pyruvate decarboxylase from Zymomonas mobilis, this Klebsiella mutant became an efficient ethanol producer. The recombinant strain produced 387 mM ethanol from 275 mM xylose in 80 h, about 83% of the theoretical maximal yield. Furthermore, this mutant consumed more than double the amount of xylose (41 g/l) compared to the wild-type, due to reduced production of inhibiting acids during growth.Dedicated to Professor Dr. Zähner on the occasion of his 60th birthday     

Cholinesterase Activities in Uterus of Normal and Fenchlorphos Treated Blue Foxes (Alopex Lagopus) during Various Reproductive States

The uterine acetylcholinesterase and total cholinesterase (acetylcholinesterase plus butyrylcholinesterase) activities in normal and fenchlorphos treated blue fox vixens were determined during various reproductive states. AChE and Total-ChE of non-medicated vixens in oestrus were about one half of those in anoestrus. In pregnant uteri (luteal phase) the activities were 25 % and 30% compared to anoestrus. In vixens given 100 mg/kg fenchlorphos for 3 weeks during anoestrus, the remaining activity of AChE in uterus were in average 37%. Pregnant and non-pregnant vixens in the luteal phase medicated prior to mating and during time of implantation, displayed AChE activities which were only moderabely reduced (remaining activities 83% and 72% compared to medicated animals in anoestrus: remaining activity 37%). Plasma ChE-activity increased during pregnancy in the controls while enzyme activity was strongly reduced in animals given 100 mg/kg fenchlorphos daily through the whole pregnancy. It was concluded that the previous reported embryotoxic effect of fenchlorphos in the blue fox did not seem to be directed towards the moderate inhibition of the uterine cholinesterases.     

The potential use of silicon compounds as oxygen carriers for free and immobilized cells containing l-amino acid oxidase

Summary The relatively low solubility of oxygen in water presents a problem in particular when immobilized cells are used or enzymes are applied for oxygen dependent reactions. The other main purpose is the requirement of oxygen for the increase of biomass. In this investigation the usefulness of silicon emulsions as oxygen carriers is demonstrated.In case of l-amino acid oxidase activity of immobilized cells, an increase by a factor of four was found in the presence of silicon emulsions. Likewise, growth medium enriched with silicon emulsions showed a significantly increased growth of cells inside alginate beads compared to normal growth medium.     

Bukettförmige Strukturen im Ependym der Regio hypothalamica des III. Ventrikels beim Kaninchen

Zusammenfassung Die Wand des III. Ventrikels (Regio hypothalamica) vom erwachsenen Kaninchen wurde elektronenmikroskopisch untersucht. — Unterschiedliche keulenförmige portsätze, deren Perikaryen in nahen und entfernten Regionen liegen, dringen in den Ventrikel ein. Sie heben eine Ependymzelle ab und bilden eine bukettförmige Struktur. Einige Fortsätze enthalten eine spärliche feingranulierte Masse, andere Bläschen (600–1500 Å) oder Bläschen mit dichtem Kern (450–1200 Å). Inmitten des Buketts kann eine Nervenzelle liegen, die einen dicken Fortsatz gegen das Hypendym schickt. Unterhalb des Buketts findet man eine andere Nervenzelle, die Fortsätze ins Bukett sendet. Zahlreiche in das Bukett eintretende Fortsätze stammen aus entfernteren Kerngebieten. Die funktionelle Bedeutung der Strukturen (Neurosekretion ? Resorption ? Rezeptor ?) wird diskutiert.

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Bouquet-like ependymal structures in the hypothalamic region of the 3rd Ventricle (rabbit)The question of neurosecretion or receptor function

Summary The wall of the III. ventricle (Regio hypothalamica) of the adult rabbit has been investigated electron microscopically. —Various bulblike processes of nerve cells, having their perikarya in close or distant regions, penetrate into the ventricle. They lift an ependymal cell and form a bouquet-like structure. Some of the processes contain a sparse granulated material and others include vesicles (600–1500 Å) or dense-cored vesicles (450–1200 Å). In the middle of the bouquet a perikaryon may be seen extending a thick process towards the hypendyma. Below the bouquet another perikaryon may be found extending several processes into the bouquet. The functional significance of these structures (neurosecretion ? resorption? receptor?) is discussed.

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Die Untersuchung wurde mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft durchgeführt.     

Intraventrikuläre markhaltige Nervenfasern nahe der Apertura lateralis ventriculi quarti des Kaninchengehirns

Zusammenfassung In der Gegend der Apertura lateralis ventriculi quarti des Kaninchengehirns wurden intraventrikuläre markhaltige Nervenfasern der Fasergruppe B gefunden. Ihre Markscheide beginnt oder endigt innerhalb des Ventrikellumens. Besonderheiten des Ependyms dieser Gegend werden mitgeteilt.

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Summary In the 4th ventricle of the brain near the apertura lateralis in rabbit myelinated nerve fibers occur. These nerve fibers belong to the fiber group B. Their myelin sheath begins or ends in the ventricular cavity. Peculiarities of the ependyma of this region are discussed.

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Die Untersuchung wurde mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft durchgeführt.     

Über die Blutkapillaren und perivaskulären Strukturen der Area postrema des Kaninchens und über ihr Verhalten im Pentamethylentetrazol-(„Cardiazol“-)Krampf

Zusammenfassung Die sinusförmigen Kapillaren der Area postrema werden von zwei Basalmembranen umgeben, die einen Raum einschließen, in dem Makrophagen liegen. Verästelte Ausläufer der äußeren Basalmembran dringen tief zwischen die Gliafortsätze ein und bilden ein Membranlabyrinth. Das Kapillarendothel ist fenestriert. Nach Cardiazolkrampf entsteht ein perivaskuläres Oedem, das das Membranlabyrinth öffnet und den perivaskulären Raum vergrößert. Das Endothel zeigt hierbei starke Cytopempsis. Die funktionelle Bedeutung der Strukturen wird diskutiert.

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Summary The sinusoid capillaries of the area postrema are surrounded by two basement membranes enclosing a perivascular space, in which macrophages are found. Ramified extensions of the outer basement membrane penetrate deeply between the glial processes forming a labyrinth of basement membranes. The capillary endothelium is fenestrated. After a Cardiazolinduced convulsion a perivascular edema opens the basement membrane labyrinth and the perivascular space is greatly enlarged. The endothelium shows pinocytotic activity. The functional significance of these structures is discussed.

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Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Zur Frage einer intraventrikulären Neurosekretion

Zusammenfassung In der vorderen Wand des IV. Ventrikels und des Canalis centralis gegenüber der Area postrema liegen beim Kaninchen Nervenzellen, deren Fortsätze intraventrikulär mit 6 großen Protoplasmakugeln endigen, die mit Mitochondrien angefüllt sind. Das Perikaryon ist reich an Ergastoplasma, alle Teile der Zelle enthalten leere, 600 bis 1500 Å messende, und ein dichtes Granulum enthaltende, 650–1000 Å große Bläschen. Vermutlich werden Stoffe in den Liquor cerebrospinalis abgegeben. Dem Plasmalemm der Nervenzellen liegen Synapsen an.

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Summary In the anterior wall of the IVth ventricle, opposite to the area postrema, nerve cells are found. Their processes end with spheroid swellings extending into the ventricle. These bulbs contain a large number of mitochondria, while ergastoplasm is seen in the perikaryon. The cytoplasm of the whole cell shows vesicles (600–1500 Å) and dense-core vesicles (650–1000 Å) which might be extruded into the liquor cerebrospinalis. The plasmalemma of the perikaryon is in contact with synapses.

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Die Untersuchung wurde mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft durchgeführt.