The nervous system of the basal mollusk Wirenia argentea (Solenogastres): a study employing immunocytochemical and 3D reconstruction techniques

Abstract

The morphology of the nervous system of Wirenia argentea (Solenogastres) is described based on histological and immunocytochemical analyses using fluorescent markers against the neurotransmitters serotonin and FMRFamide, as well as acetylated α-tubulin, in combination with confocal laser-scanning microscopy. The nervous system displays a distinct tetraneury with fused cerebral ganglia, large pedal ganglia, and longitudinal nerve cords connected by regularly spaced connectives and commissures resulting in an orthogon-like arrangement. There is no indication of metamery. FMRFamidergic immunoreactivity is present in most compartments of the nervous system, while serotonergic immunoreactivity appears to be restricted to the longitudinal nerve cords, the cerebro-pedal commissure and part of the cerebral ganglion. The buccal system shows immunoreactivity against none of the neurotransmitters.

Keywords:

• Aplacophora
• FMRFamide
• Mollusca
• neuroanatomy
• serotonin
• α-tubulin

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

This study was conducted in the course of a European Union SYNTHESYS project (DK-TAF-1772) at the University of Copenhagen, Denmark, granted to CT. Thanks to Rick Hochberg for technical advice and to Christoffer Schander for helpful comments on the manuscript. AW is grateful for financial support by the Danish Research Agency (grants 21-04-0356 and 272-05-0174) and the Carlsberg Foundation (grant 2005-1-249).

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark