Dataset for "Stereoanatomy analysis of the early cephalized central nervous system in a marine planarian, Stylochoplana pusilla"

Published: 9 March 2023| Version 1 | DOI: 10.17632/d42d3jstf5.1
Hirotaka Sakamoto


Platyhelminthes are a phylum of simple bilaterian invertebrates with prototypic body systems. Compared with non-bilaterians such as cnidarians, the bilaterians are likely to exhibit integrated free-moving behaviors, which require a concentrated nervous system “brain” rather than the distributed nervous system of radiatans. Thus, marine planarians have an early cephalized ‘central’ nervous system compared not only with non-bilaterians but also with those parasitic flatworms or freshwater planarians. Here, we investigated the 3-D structures of the planarian central nervous system by the use of X-ray micro-computed tomography (micro-CT) in a synchrotron radiation facility. We identified, in marine planarians, both an apparent optic chiasm (a well-known feature in vertebrates) and mushroom bodies (prominent in insects). These results suggest that the marine planarian “brain” provides a valuable ‘missing-link brain’ between those of the protostome and deuterostome, especially in the evolutionary aspects of the nervous system.



Okayama Daigaku


Animal Research


Japan Society for the Promotion of Science

to T.I.; 17K07943, 21K05772, to T.S.; 20K21429, 21H00428; 21H02520, 22K19312; and to H.S.; 16H06280, 20K06722, 22H02656; 22K19332

Takeda Science Foundation

to H.S., Bioscience Research Grants

Suzuken Memorial Foundation

to HS; 19-085