ABSTRACT
A new method of making preparations was used to analyse the neuroeffector connections of the paired giant neurons of the African snail Achatina fulica. These neurons were found to induce postsynaptic potentials in the muscles of the mantle, heart, the wall of the pulmonary cavity, and the muscular elements of the renal complex, the pericardium, the sexual apparatus, the walls of the cerebral arteries, the filaments of the columellar muscles, the wall of the abdomen, and the tentacle retractor muscles. Rhythmic neuron activity led to the development of marked facilitation and long-term potentiation of synaptic potentials. The possible significance of the multiple neuroeffector connections of giant neurons is discussed.
Subject(s)
Excitatory Postsynaptic Potentials/physiology , Heart/innervation , Heart/physiology , Motor Neurons/physiology , Muscle, Skeletal/innervation , Muscle, Skeletal/physiology , Neural Pathways/physiology , Neuroeffector Junction/physiology , Snails/physiology , Adaptation, Physiological/physiology , Animals , Long-Term Potentiation/physiologySubject(s)
Ganglia, Invertebrate/physiology , Muscles/physiology , Neural Pathways/physiology , Neurons/physiology , Snails/physiology , Synaptic Transmission/physiology , Animals , Electric Stimulation , Escape Reaction/physiology , Ganglia, Invertebrate/cytology , Muscle Contraction/physiology , Muscles/innervation , Neuromuscular Junction/physiologyABSTRACT
Using a new method of animal preparation, the efferent connections of giant paired neurons on the dorsal surface of visceral and right parietal ganglia of snail, Achatina fulica, were examined. It was found that spikes in giant neurons d-VLN and d-RPLN evoke postjunctional potentials in different points of the snail body and viscerae (in the heart, in pericardium, in lung cavity and kidney walls, in mantle and body wall muscles, in tentacle retractors and in cephalic artery). The preliminary analysis of synaptic latency and facilitation suggests a direct connections between giant neurons and investigated efferents.
Subject(s)
Ganglia, Invertebrate/physiology , Neurons/physiology , Snails/physiology , Animals , Snails/anatomy & histology , Synaptic TransmissionABSTRACT
9 cardioregulating neurones belonging to 5 different functional groups were studied in visceral and right parietal ganglia of the Giant African snail Achatina fulica. The neuronal network included multimodal and multifunctional cells exerting short- or long-lasting chronoionotropic effects on the cardiac electro- and mechanograms. Mechanisms of the differences in the cardioregulating effectiveness of these groups were discussed.
