This work was supported in part by National Institutes of Health grant MH-07603-02 EPR-01 and National Aeronautics and Space Administration grant NsG-625.
Electron microscopic studies of planaria. III. Some observations on the fine structure of planarian nervous tissue†
Version of Record online: 1 JUN 2005
Copyright © 1966 Wiley-Liss, Inc., A Wiley Company
Journal of Experimental Zoology
Volume 161, Issue 3, pages 391–411, April 1966
How to Cite
Morita, M. and Best, J. B. (1966), Electron microscopic studies of planaria. III. Some observations on the fine structure of planarian nervous tissue. J. Exp. Zool., 161: 391–411. doi: 10.1002/jez.1401610307
- Issue online: 1 JUN 2005
- Version of Record online: 1 JUN 2005
The small size of the nerve fibers of the planarian nervous system render the details of its neuroanatomy invisible to optical microscopy. Electron microscopic studies on the nervous system of Dugesia dorotocephala are described showing the neuropil of the brain, the origin of the ventral nerve cords from the brain neuropil, synaptic junctions in the neuropil, and “giant” fibers in the longitudinal conduction system. Two major kinds of synapses can be discerned as well as the pre- and post-synaptic sides of each. There appear to be three major kinds of cells comprising the brain; neurons, neurosecretory cells, and neuroaccessory cells. The neurons are unmyelinated, contain neurotubules, and appear to synapse only in the centrally located neuropil.