Worm Breeder's Gazette 8(2): 31
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
The anatomy of the nervous system of the large parasitic nematode Ascaris des is similar in many respects to the nervous system of C. elegans. An adult Ascaris can be as large as 30 cm and weigh 10 grams while a typical C. elegans may be 1 mm long and weigh a few micrograms. Yet, both worms have about the same number of neurons. In addition, the nerve cells are arranged in the same basic pattern throughout the animals and many of the neurons have similar shapes in the two worms. It has been known for some time, for example, that motorneurons in the two animals have identical shapes and make similar synaptic connections. On the other hand, homologies between interneurons in the two species have been less clear. In order to compare different classes of neurons more fully, we have examined the anatomy of the retrovesicular ganglion (RVG) of Ascaris, which contains both interneurons and motorneurons. We find that each RVG cell in Ascaris appears to have a homolog in the RVG of C. elegans. The homologies are based on the unpublished reconstructions of head neurons by John White. [see Figure 1]