Egg-species recognition in cannibalistic hatchlings of the land snailsArianta arbustorum andHelix pomatia

Summary Laboratory experiments were conducted to determine whether cannibalistic hatchling of the land snailsArianta arbustorum andHelix pomatia discriminate between eggs of the two species. Hatchlings from both species showed a significant choice for conspecific eggs and consumed on average 1 egg in 4 days. Eggs from the other species were only occasionally eaten.     

Neural serotonin receptors in active and hibernating helicid snails (Helix lucorum)

Summary In hibernating snailsHelix lucorum, the effect of 5-HT on neurons of an identified group is mainly hyperpolarization associated with a conductance increase, while, in active snails, the effect is depolarization and a decrese of the membrane conductance.     

Bestimmung des DNS-Gehaltes in Zellkernen des Nervengewebes vonHelix pomatia L. undPlanorbarius corneus L. (Stylommatophora und Basommatophora,Gastropoda)

Summary It has been demonstrated by cytophotometric measurements of the DNA-content in glial- and nerve cells of the snailsHelix pomatia (Stylommatophora) andPlanorbarius corneus (Basommatophora) that the giant nuclei of nerve cells in the central ganglia contain more than tens of thousands of DNA compared with sperm nuclei. According to the DNA-content of sperms (=n), the values for glial cells are between 2n and 4n for both species.

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Herrn Prof. Dr. W.Dittrich, Institut für Strahlenbiologie der Universität Münster, danke ich für die Möglichkeit, am UMSP I arbeiten zu dürfen; Frl. A.Stipproweit danke ich für sorgfältige technische Assistenz.     

In vitro synthetic activity of the juvenile ovotestis ofHelix aspersa: Influence of the brain and the dorsal bodies

Summary A bioassay was developed inHelix aspersa to study the effect of known endocrine centers on the twomonth-old gonad, using organ culture. The incorporation of¹⁴C leucine and³H fucose in the juvenile gonad almost doubled over control levels, in the presence of the brain and the dorsal bodies.     

An incomplete anti-B agglutinin in the eggs of the prosobranch snailPila ovata

Zusammenfassung In den Eiern der SchneckePila ovata wurde ein Agglutinin aufgefunden, welches in «inkompletter» Weise mit einem Blutgruppen-B-ähnlichen Antigen von verschiedenen Erythrozyten reagiert. Agglutinations-und Agglutinationshemmtiter werden mit denen von den verwandten SchneckenPomacea urceus undPomacea canaliculata verglichen.     

Cytochromeh fromAplysia depilans L.

Riassunto Nell'epatopancreas di due Gasteropodi marini:Aplysia depilans eA. limacina è presente un emocromogeno assai simile al citocromoh di Helix. Il pigmento è stato estratto e purificato e le sue proprietà fisiche, chimiche e biologiche sono state confrontate con quelle dell'emoproteina di Helix.     

Biosynthèse in vitro d'octopamine par le système nerveux et le cœur du mollusque gastéropodeHelix pomatia

Summary The tyrosine is decarboxylated in vitro by the central nervous tissue and by the intracardiac nervous tissue ofHelix pomatia by aromatic amino-acid decarboxylase. The tyramine obtained is the partially transformed into octopamine by tyramine--hydroxylase. The inhibition of monoamine oxidase favours apparition of the 2 amines. The monoamine oxidase seems able to regulate their synthese and to assure their inactivation.

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Biosynthèse in vitro d'octopamine par le système nerveux et le cur du mollusque gastéropodeHelix pomatia

     

Intracellular injection of cAMP and cGMP into snail neurones induces an increase in Na+-conductance

Summary Injection of cAMP and more rarely cGMP into the neurones of the snailHelix pomatia induces an increase in membrane conductance, membrane depolarization and excitation. The effect is theophylline-dependent and has a reversal potential near — 10 mV.     

Über die Funktion der Eiweissdrüse vonHelix pomatia

Summary A strong immunological crossreactivity between the extracts of the albumin gland of snails (Helix pomatia) and the content of snail eggs is described, suggesting that the former supplies the eggs with protective substances (agglutinins, protease-inhibitors).     

Methods of metal incorporation into intracellular granules

Summary The hepatopancreas of the garden snail (Helix aspersa) contains basophil cells which produce intracellular granules of CaMgP₂O₇. A variety of metals are incorporated into these granules either by direct substitution or by the synthesis of new pyrophosphate material.Supported by NERC grant GR3/3063.     

Effects of dopamine antagonists on snail locomotion

Summary Dopamine antagonists which affect the ergometrine-sensitive type of dopamine receptors produce characteristic motor disorders in a land snail,Helix pomatia L.Acknowledgment. We are grateful to Dr L. Hiripi for valuable suggestions and Dr I. Varanka for help in photography.     

Interactions between two identified cells in the visceral ganglion of the snail,Helix pomatia

Summary An interneurone, making excitatory synaptic connections with a second neurone has been identified in the brain ofHelix pomatia. The results suggest that the connection is monosynaptic.We thank the M.R.C. for a Training Grant to S.E.J.     

Inhibition of temperature-induced spermatogenic proliferation by a brain factor in hibernatingHelix aspersa (Mollusca)

Summary Ablation of the brain from hibernatingHelix aspersa maintained at 25°C causes a significant increase in the proliferation of male cells in the gonad, whereas the ablation of the optic tentacles has no effect. The brain, therefore, produces a factor which specifically inhibits the multiplication of spermatogonia and spermatocytes.     

Degradation of bacterial lipopolysaccharide by gut juice of the snailHelix pomatia

Summary Lipopolysaccharides from several bacteria were selectively degraded by gut juice of the snailHelix pomatia with extensive loss of anticomplementary activity and changes in the electrophoretic pattern in polyacrylamide gels. The gut juice had little effect on ketodeoxyoctonate content or immunodominant sugars. The lipid A moiety of the lipopolysaccharide appeared to be the main site of attack.     

Evidence for serotonin (5-hydroxytryptamine) as transmitter in the penis retractor muscle ofHelix pomatia L.

Summary Microchromatography of dansylated substances was used to estimate the serotonin content of the penis retractor muscle (PRM) ofHelix pomatia. Pharmacological data in connection with the biochemical results suggest that 5-HT plays a role in the regulation of the mechanical activity of the PRM.     

The presence of octopamine in the brain ofHelix aspersa and its action on specific snail neurones

Résumé L'octopamine est présente dans le tissue nerveus l'escargot,Helix aspersa. Elle a un effet fortement inhibitoire sur certains neurones. Ces neurones sont aussi sensibles à la dopamine et à la noradrénaline. Le mécanisme possible de l'action de l'octopamine est discuté.     

Prokaryote-eukaryote interactions in trace element metabolism.Desulfovibrio sp. inHelix aspersa

Summary Snails (Helix aspersa) contain sulphate-reducing bacteria in their crops. Feeding such animals on food containing sulphate and molybdate ions does not induce a copper deficiency and in fact the bacteria appear to facilitate metal absorption. This is in contrast to the effects of these bacteria in ruminant cattle.     

Obtention de lignées cellulaires en culture de tissus d'invertébrés

Zusammenfassung In Gewebekulturen vonBombyx mori -Gonade und und vonHelix aspersa-Bindegewebe abimpfbare Fibroblasten-Zellenstämme wurden erhalten. Die Zusammensetzung der Nährflüssigkeiten ist gegeben, und es wird auf Schwierigkeiten in der Gewebekultur Wirbelloser hingewiesen.     

Effect of acetylcholine,dopamine, noradrenaline and 5-hydroxytryptamine on the incorporation of32P into phospholipids of the snail brain

Zusammenfassung Von den im Schneckenhirn (Helix pomatia) wahrscheinlich als Neurotransmitter wirkenden Substanzen führen Dopamin und Acetylcholin zu einem erhöhten Einbau von³²P in Phospholipide; Serotonin zeigt eher einen gegenteiligen Effekt und Noradrenalin bleibt ohne Einfluss. Phosphatidylinositol weist die höchste Einbaurate auf. Die Resultate unterstreichen die Bedeutung von Dopamin, Acetylcholin und Serotonin als Neurotransmitter im Schneckenhirn und deren Einfluss auf den Metabolismus von Membranphospholipiden.     

Einbau von H3-thymidin in zellen und gewebe vonHelix pomatia L. (gastropoda,pulmonata)

Summary It has been demonstrated by injections of H³-Thymidine into adult and juvenile snails (Helix pomatia) that the mitotic activity in the central nervous system, the connective tissue and epidermis was generally higher in juvenile animals than in adult ones. Data are given for the amount of triated thymidine labelled nuclei in the tissues, which are investigated.