Synaptic connections made by two serotonin-containing neurons in the snail (Helix pomatia) brain

Résumé On décrit la disposition précise des contacts synaptiques réalisée par deux gigantesques neurones contenant de la sérotonine (GSC) avec d'autre neurones dans la cervelle de l'escargotHelix pomatia. Quelques neurones sont innervés deux fois par chaque GSC.     

Degradation of bacterial lipopolysaccharide by gut juice os the snail Helix pomatia.

Lipopolysaccharides from several bacteria were selectively degarded by gut juice of the snail Helix 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.     

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.     

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

An interneurone, making excitatory synaptic connections with a second neurone has been identified in the brain of Helix pomatia. The results suggest that the connection is monosynaptic.     

In vitro biosynthesis of octopamine by the nervous system and the heart of the mollusc gastropode Helix pomatia (author's transl)]

The tyrosine is decarboxylated in vitro by the central nervous tissue and by the intracardiac nervous tissue of Helix pomatia by aromatic amino-acid decarboxylase. The tyramine obtained is then partially transformed into octopamine by tyramine-beta-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.     

The function of the intestine in the pulmonate mollusc Helix pomatia L.

Summary Everted sacs of intestine from Helix pomatia do not actively transfer glucose, galatose, methionine, alanine, asparagine, aspartic acid or proline from the mucosal to serosal surfaces. The principal function of the intestine appears to be the reabsorption of water.The study was partly financed through a Reading University Research Board Scholarship. I thank Profs A. Graham, K. Simkiss, J. Machin and Dr C. Kyriakides for their advice and criticisms and E. Snowden and J. Counden for technical assistance.     

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.