Possible Transmitter Functions of Acetylcholine and an RFamide-Like Substance in Sagitta (Chaetognatha)
The locomotor muscle fibres of the chaetognath Sagitta are probably multiply innervated and, although linked by numerous gap junctions, do not appear to be coupled electrically. Acetylcholine evokes contraction of the locomotor muscle; iontophoretic application of acetylcholine evokes membrane depol...
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Published in | Proceedings of the Royal Society. B, Biological sciences Vol. 230; no. 1258; p. 1 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
The Royal Society
23.02.1987
|
Online Access | Get full text |
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Summary: | The locomotor muscle fibres of the chaetognath Sagitta are probably multiply innervated and, although linked by numerous gap
junctions, do not appear to be coupled electrically. Acetylcholine evokes contraction of the locomotor muscle; iontophoretic
application of acetylcholine evokes membrane depolarizations and a series of spikes resembling those seen during spontaneous
activity. Both effects are reversibly abolished by (+)-tubocurarine. Acetylcholinesterase is found associated with the sarcolemmata,
and it is suggested that acetylcholine is a possible candidate for the neuromuscular transmitter. Immunocytochemical studies
with antisera raised against the sequence Arg-Phe-amide (RFamide) show that many neurons in the brain and ventral ganglia
contain an RFamide-like material. Some of these neurons are associated with the innervation of sensory organs; others may
belong to coordinating systems. At present, these observations do not indicate the affinity of the Chaetognatha to any other
invertebrate phylum. |
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ISSN: | 0962-8452 1471-2954 |
DOI: | 10.1098/rspb.1987.0007 |