Molecular and Genetic Approaches for the Analysis of C. elegans Neuronal Development - Caenorhabditis Elegans: Molecular Genetics and Development - page 409

Fig. 1 Overview of the C. elegans nervous system. (A) The C. elegans nervous system visualized by a
pan-neuronal GFP. This image is courtesy of Dr. Harald Hutter. (B) Ultrastucture of the ventral nerve cord
(VNC), shown as an electron micrograph of cross-section. This image is adapted with permission from
White et al. (1986) . (C) GFP labeling of the GABAergic motor neurons (Green arrowheads mark the
ventral cord neurons); the image is adapted with permission from Knobel et al. (2001) . (D) An electron
micrograph of the ultrastructure of a chemical synapse between a motor neuron and muscle cell. This
image is adapted with permission from Nakata et al. (2005) . (E) An electron micrograph image of the
ultrastructure of a gap junction between a hypodermal cell and excretory cells. This image is adapted with
permission from Chuang et al. (2007) . (For color version of this figure, the reader is referred to the web
version of this topic.)
dendrites of the amphid and phasmid sensory neurons, and GLR cells (6 cells) are
located near the nerve ring and form a thin cyclindrical sheet between the pharynx
and the nerve ring. Recent studies have shown that these glial cells play important
roles in the development and maintenance of the nervous system ( Shaham, 2006 ).
Within the nerve ring or bundle, nerve processes are positioned in a stereotypical
neighborhood pattern. An example is shown in Fig. 1 C, which shows the position and
axonal trajectory of the GABAergic motor neurons. Chemical synapses are formed en
passant between specific partners, either along the entire nerve or at defined regions