Some interesting points on the histochemistry of the cytoplasmic inclusions of the ageing spinal neurones of reptiles,birds and mammals

Résumé L'analyse histochimique comparée des neurones des Reptiles, des Oiseaux et des Mammifères révèle que les divers corps qui y sont inclus ont une histochimie identique. Les sphéroïdes lipides abondent dans les phospholipides des jeunes neurones qui sont transformés en corps triglycérides chez les adultes. Les corps lipides ne sont pas un produit de sécrétion de l'appareil canaliculaire de Golgi dont l'homologue a été observé seulement dans les neurones adultes. La substance de Nissl est pleine de RNA.     

Action of glutamic acid and of some glutamate analogues on the molluscan central neurones

Summary The effects of L-glutamic acid and of some glutamate analogues have been studied on the central nervous system of the snailHeobania vermiculata, using conventional electrophysiological techniques. The glutamate H-response had the mean equilibrium value of-(57±4) mV and was associated with a Cl^– conductance change. The D-response to glutamate application showed an involvement of sodium ions. Aspartate was agonist of glutamate action and displayed similar equilibrium value of the H-response, whereas quisqualate H-response was non-invertible.The authors wish to express their thanks to Prof. A. Curatolo for his continual interest and advice, and to Dr J. Stinnakre for the criticism of the text.     

Ionic mechanisms underlying the depolarization of L-glutamate on rat and human spinal neurones in tissue culture

Zusammenfassung Die Wirkung von Glutamat wurde auf das Membranpotential von Rückenmarkneuronen des Menschen und der Ratte in Gewebekultur untersucht. Entfernung der Natriumionen aus der extrazellulären Flüssigkeit führt zu einem Verschwinden der durch Glutamat erzeugten Depolarisation. Diese Befunde weisen darauf hin, dass Glutamat, welches eine vermutliche Überträgersubstanz im Rückenmarkist, die Permeabilität der Neuronenmembran für Natriumionen erhöht. Die Versuche zeigen ferner, dass die Gewebekultur ein ausgezeichnetes Modell ist zur Abklärung von ionalen Mechanismen, welche der Wirkung von Überträgersubstanzen im Zentralnervensystem zugrunde liegen.     

Histochemical remarks on monoamine oxidase and acetylcholinesterase in some regions of amphibian brain

Summary The histochemical localization of monoamine oxidase and acetylcholinesterase has been studied in the cerebellum, optic tectum and telencephalon of three amphibian species. For acetylcholinesterase in particular, different histochemical methods and selective inhibitors have been used in order to investigate the actual nature of enzymatic activity revealed.     

Selective antagonism by Mg2+ of amino acid-induced depolarization of spinal neurones

Summary In the isolated frog or rat spinal cord, low concentrations of Mg²⁺ (0.5–1.00 mM) markedly depress, in a substantially Ca²⁺-independent manner, ventral root depolarizations produced by dorsal root stimulation and by certain amino acids (e. g. N-methyl-D-aspartate and L-homocysteate) but do not depress depolarizations produced by other excitatory amino acids (e. g. kainate and quisqualate). L-Aspartate-induced depolarizations are more sensitive to Mg²⁺ then are L-glutamate-induced depolarizations.Acknowledgment. We thank D. J. Oakes for skilled technica assistance. This work was supported by the Medical Research Council.     

Organization of the ventral branchial and lumbar horns of the spinal cord in embryos of snake-like and tetrapod reptiles]

In embryos of Snake-like Reptiles (Anguis fragilis) and of Ophidians (Tropidonotus, Python), the lay-out of motor neuroblast in the ventral horns of the spinal cord, in the brachial and the lumbar regions differs from the one observed in the same regions of embryos of tetrapod Reptiles (Lacerta viridis).     

Mass and RNA content of rat spinal anterior horn neurones during postnatal development

Zusammenfassung Die postnatale Entwicklung der Trockenmasse und des RNS-Gehaltes isolierter spinaler Vorderhornzellen der Ratte wurden mit quantitativen Methoden untersucht, wobei eine postnatale, 3,6fache Vermehrung der Nervenzellmasse und eine 4,2fache des RNS-Gehaltes beobachtet wurde. Bereits im Alter von einem Monat werden nahezu endgÜltige Werte erreicht.     

Electron microscopic observations on the spinal projections to the cerebellar nuclei in the cat and rabbit

Zusammenfassung Bei Katze und Kaninchen wurden Projektionen vom Rückenmark zu den Kleinhirnkernen elektronenmikroskopisch untersucht und nach Läsionen des Halsmarkes wurden viele degenerierte Endknöpfe der Kollateralen des Tractus spinocerebellares in den Nuclei medialis und interpositus gefunden.     

Selective antagonism by Mg2+ of amino acid-induced depolarization of spinal neurones.

In the isolated frog or rat spinal cord, low concentrations of Mg2+ (0.5-1.00 mM) markedly depress, in a substantially Ca2+-independent manner, ventral root depolarizations produced by dorsal root stimulation and by certain amino acids (e.g. N-methyl-D-aspartate and L-homocysteate) but do not depress depolarizations produced by other excitatory amino acids (e.g. kainate and quisqualate). L-Aspartate-induced depolarizations are more sensitive to Mg2+ then are L-glutamate-induced depolarizations.     

General effects of cytosine arabinoside on the embryo of reptiles

Administered to eggs of Reptilia (Lacerta viridis and Anguis fragilis), cytosine-arabinoside induced numerous embryonic malformations, among which microphthalmia and limb deformities. On the other hand this drug delayed the retrogression of the apical ridge of the limb buds in Anguis fragilis.     

The chemoarchitectonics in the forebrain of reptiles

Zusammenfassung Ausgehend vom Vorderhirn der Reptilien als schematischer Typus für Säugerverhältnisse, wurden histochemische Untersuchungen von Monoaminoxydase und Succinodehydrogenase im Vorderhirn der Schildkröten ausgeführt. Die Monoaminoxydasereaktion ist in den visceralen Abteilungen, dem limbischen System, Area preoptica und Hypothalamus stark, während die Succinodehydrogenasereaktion im Neostriatum, Paleostriatum und Nucleus rotundus des Thalamus dorsalis stärker zu sein scheint. Die Befunde lassen die Verteilungen der Enzymaktivität im kompliziert gebauten Vorderhirn der Säuger befriedigend erklären.     

Uptake ofl-glutamate andl-aspartate in neurones and glial cells of cultured human and rat spinal cord

Summary Autoradiographic investigations on the uptake ofl-glutamate andl-aspartate have shown that the amino acids were taken up by neurones as well as by glial cells of cultured human and rat spinal cord. The activity of glutamate and aspartate varied considerably between individual neurones, whereas glial cells showed a more even distribution of the labelled amino acids. Our results suggest that both neurones and glial cells are involved in the uptake of amino acid transmitters.     

Histochemical and cytochemical observations on the acetylcholinesterase (AChE) localization in the superior cervical ganglion (SCG) after preganglionic sympathectomy of the neonatal rat

Summary Results of histochemical and cytochemical reactions show that after the section of preganglionic nerve trunk performed in newborn animals, the appearance and the individual increase in AChE activity in non-innervated nerve cells follow the pattern of normally innervated ganglion cell.