Three-dimensional reconstruction of the central nervous system of Macrobiotus hufelandi (Eutardigrada, Parachela): implications for the phylogenetic position of Tardigrada

@article{Zantke2007ThreedimensionalRO,
  title={Three-dimensional reconstruction of the central nervous system of Macrobiotus hufelandi (Eutardigrada, Parachela): implications for the phylogenetic position of Tardigrada},
  author={Juliane Zantke and Carsten Wolff and Gerhard Scholtz},
  journal={Zoomorphology},
  year={2007},
  volume={127},
  pages={21-36}
}
The morphology of the central nervous system of the tardigrade species Macrobiotus hufelandi was analysed with anti α-tubulin immunostaining in combination with confocal-laser-scanning-microscopy and computer aided three-dimensional reconstruction. The brain anatomy is unexpectedly complex with distinct tracts and highly intermingled nerve fibres. In contrast to older descriptions, we could not detect a suboesophageal ganglion. Furthermore, we found no evidence for a tripartite/three-segmented… 

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References

SHOWING 1-10 OF 75 REFERENCES
Polychaete nervous systems: Ground pattern and variations--cLS microscopy and the importance of novel characteristics in phylogenetic analysis.
TLDR
Immunohistochemical investigations in Annelida enable more detailed reanalyses of known structures and detection of new characteristics that are useful for phylogenetic analyses and it is shown that hitherto unknown nerves are present in the peripheral nervous system.
The brain of Echiniscus viridissimus Peterfi, 1956 (Heterotardigrada): a key to understanding the phylogenetic position of tardigrades and the evolution of the arthropod head
TLDR
The analysis suggests that the brain is derived from nervous elements of four segments with the fourth segment having contributed paired dorsal ganglia and their connecting vertical tracts to the first trunk ganglia of the ventral chain.
The cerebral ganglia of Milnesium tardigradum Doyère (Apochela, Tardigrada): Three dimensional reconstruction and notes on their ultrastructure
TLDR
Differential interference contrast micrographs from stretched animals, serially sectioned semi-thin and ultrathin sections revealed that the cerebral ganglia of the eutardigradeMilnesium tardigradumlie has an anterior indentation which is penetrated by two muscles that arise from the cuticle of the forehead.
The Nervous Systems of Invertebrates: An Evolutionary and Comparative Approach
TLDR
The nervous systems of Cnidarians, Onychophora, Echinodermata, Chelicerata and Annelida are studied.
Neurophylogeny: Architecture of the nervous system and a fresh view on arthropod phyologeny.
  • S. Harzsch
  • Medicine, Biology
    Integrative and comparative biology
  • 2006
TLDR
A thorough overview is given of characters derived from structure and development of the arthropod brain and the ventral nerve cord from the cellular level to the level of larger neuropil systems that support the new Tetraconata hypothesis suggested by Dohle and provide evidence for a clade that unites malacostracan and remipede crustaceans with the Hexapoda.
Electron microscopic investigation of cephalic sense organs of the tardigradeMacrobiotus hufelandi C.A.S. Schultze
TLDR
With regard to the possible functions of the four sensory regions, the ALSF is discussed as a mechanoreceptive organ and the type 1 sensory cells in the COSF are suggested to be chemoreceptive and thetype 2 sensory cells to serve as me-chanoreceptors in theCOSF.
Immunolocalization of serotonin in Onychophora argues against segmental ganglia being an ancestral feature of arthropods
TLDR
These results contradict a priori assumptions of segmental ganglia of the typical euarthropodan type being an ancestral feature of Onychophora and weaken the traditional Articulata hypothesis, which proposes a sistergroup relationship of Annelida and Arthropoda.
The Evolution of Arthropod Nervous Systems: Insights from Neural Development in the Onychophora and Myriapoda
TLDR
Current understanding of mechanisms for neurogenesis and the establishment of early axon pathways in the central nervous system (CNS) of Onychophora and Myriapoda are reviewed.
Phylogenetic comparison of serotonin‐immunoreactive neurons in representatives of the Chilopoda, Diplopoda, and Chelicerata: Implications for arthropod relationships
  • S. Harzsch
  • Medicine, Biology
    Journal of morphology
  • 2004
TLDR
The data discussed in this article moderately support the Tetraconata hypothesis, and the proposed ground patterns of the various groups are reconstructed and the characters are plotted on two competing hypotheses of arthropod phylogeny, the traditional Tracheata hypothesis and an alternative hypothesis derived from molecular and recent morphological data, the Tumenata concept.
The organization and evolutionary implications of neuropils and their neurons in the brain of the onychophoran Euperipatoides rowelli.
TLDR
The present account identifies three cerebral divisions, the first of which contains primary olfactory neuropils, visual neuropil, and brain regions that correspond anatomically to the mushroom bodies of annelids, chelicerates, myriapods, and insects.
...
1
2
3
4
5
...