NeuroFIG 2A-C: Placement and topology of somatic neurons.
A&B. Schematic cross sections through the anterior midbody. Neurons are bounded by the basement membrane of the hypodermis. The lateral touch receptor neurons (ALM in the anterior body, PLM in the posterior body) run on the peripheral side of the hypodermis, whereas VNC, DC, and canal-associated nerves run on the inside between the hypodermis and pseudocoelom. The sublateral (subdorsal and subventral) cords lie just inside a thin layer of hypodermis near body wall muscles. (Orange) Basal lamina; (yellow) pseudocoelom; (green) body wall muscle.
C. Sensory nerves in the head. Cross section near the lips. Most of the neurons are components of the various head sensilla with associated sheath and socket cells. Exceptions are URX, URY, BAG, and FLP neuron processes that run in the sensillar nerves but do not end in the sensillar endings. Outer labial quadrant (OLQ) nerves and cephalic (CEP) nerves have fourfold symmetry, whereas inner labial (IL1 and IL2) nerves have sixfold symmetry. Amphid nerves and outer labial lateral (OLL) nerves have twofold symmetry and run on the sides of the head. (Bright aqua) Amphid sheath; (dark aqua) sheath of the other sensilla; (purple) pharyngeal epithelium; (green) head muscle cell quadrants; (beige) hypodermis; (PH) buccal cavity pharyngeal lumen. Cross section roughly corresponds to a transmission electron microscopy (TEM) section between MRC N2 (“nose”) 3731-4 and 3731-19 (not shown).
See also NeuroFIG 2D&E
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