Note

Cephalopod Brain Terminology

Richard E. Young, Michael Vecchione, and Katharina M. Mangold (1922-2003)

Cephalopoda Glossary


A ventral view of this brain and the optic lobes can be found here.

J. Z. Young, the leading authority on the cephalopod nervous system in the latter half of the 20th century, divided the cephalopod brain into two regions: the supraesophageal mass and the subesophageal mass. These regions are joined laterally by two regions, the basal lobes and the dorsal magnocellular lobes. This arrangement suggest the ancestral brain was formed from two partially-circumesophageal cords that included the middle and posterior subesophageal masses and that these were fused dorsally with a third cord, the supraesophageal mass. The supra- and subesophageal masses further connected by the cerebro-brachial connective that runs between the anterior regions. The latter connection involves the anterior subesophageal mass and the superior buccal lobes. In decapodiforms these lobes are well removed from the rest of the brain and suggests that either they were not part of the original circumesophageal chords or formed a separate more anterior cord.

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Figure. Lateral view of the brain of Vampyroteuthis infernalis reconstructed from histological sections. Drawing modified from Young (1967).

The masses of the more posterior portion of the brain are joined laterally by the complex basal lobes and the dorsal magnocellular lobes. The separate nature of the lobes that join the supra- and subesophageal masses and, therefore, evidence for two rather than one ancestral cords, is apparent from the presence of a fissure between these regions (see dark area in drawing of Vampyroteuthis brain) which completely separates them at one point and a ventral fissure between the middle and posterior subesophageal masses which forms a path for the cephalic arteries (not visible in this drawing).

In Nautilus, the three cords that comprise the brain are more apparent. The two ventral cords partially fuse prior to their joining the dorsal cord. This fusion is apparent by their slight more dorsal separation where a fissure (J. Z. Young, 1965) separates the magnocellular lobe, at one point, from a more anterior brachial lobe (comparable to the anterior and middle subesophageal masses of coleoids) and therefore lies at the same point as the fissure in Vampyroteuthis. In Nautilus the two ventral cords, while joined laterally, are entirely separate over most of their length ventrally.

References

Young, J. Z. (1971). The Anatomy of the Nervous System of Octopus vulgaris. Claredon Press, Oxford. 690pp.

Young, J. Z. 1965. The central nervous system of Nautilus. Phil. Trans. R. Soc. B, 249: 1-25.

Young, R.E. 1967. Homology of retractile filaments of vampire squid. Science, 156(3782):1633-1634.

About This Page


University of Hawaii, Honolulu, HI, USA


National Museum of Natural History, Washington, D. C. , USA

Katharina M. Mangold (1922-2003)
Laboratoire Arago, Banyuls-Sur-Mer, France

Page: Tree of Life Cephalopod Brain Terminology Authored by Richard E. Young, Michael Vecchione, and Katharina M. Mangold (1922-2003). The TEXT of this page is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

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