Some Neuron-Hypodermis Relationships in the Parasitic Nematode Trichurus myocastoris Enigk

The association of neurons and hypodermal cells in longitudinal nerve chords and in interchordal positions (perhaps dorso-ventral commissures) in the body wall of Trichuris myocastoris Enigk has been examined with the electron microscope. Nerve chords are composed of several groups of neurons separated by processes of hypodermal cells; such groups may be functionally separate. Nerve cell bodies occur within the chords, and appear to be at least bipolar. Neurons emerge from the median chords and enter the interchordal regions, showing progressive invagination in hypodermal tissue with increased distance from the median line. Such invagination results in formation of mesaxons and may be significant in the nutrition of the neuron. Mesaxons may branch and may enclose single or groups of neurons; no spiralling of the mesaxon was seen. Occasionally more than one mesaxon was traced to a single neuron.