title: Structure, development, and maintenance of the nerve net of the body column in Hydra.
abstract: The anatomy and developmental dynamics of the nerve net in the body column of Hydra viridissima were examined immunocytochemically with a monoclonal antibody (CC04) that recognizes an antigen in nerve cells and with an antiserum against vasopressin. CC04+ neuron cell bodies, their neurites, and vasopressin-like-immunoreactive (VLI+) neurites could be clearly visualized on whole-mount preparations. All neurites of the CC04+ neurons in the body column were VLI+. However, only half of the VLI+ neurites in the body column were CC04+. Immunocytochemical analysis of macerated preparations showed that half of the neurons in the gastric region of the body column were CC04+. These results suggest that most of the neurons in the gastric region are VLI+. The density of the VLI+ neurites was uniform along the entire length of the body column. The CC04+ neuron density in the gastric region remained constant at all stages of asexual development and during foot regeneration. After pulse-labeling with 5-bromo-2'-deoxyuridine (BrdU), CC04+ neurons with labeled nuclei appeared in the body column. We conclude that neuron density in the gastric region is maintained at a constant value by insertion of new neurons in parallel with continuous epithelial cell division.
authors.affiliation: Department of Biology, Faculty of Education, Shinshu University, Nagano, Japan. BIOLOGY@GIPNC.SHINSHU-U.AC.JP
authors.forename: M
authors.initials: M
authors.lastname: Sakaguchi
authors.forename: A
authors.initials: A
authors.lastname: Mizusina
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayakawa
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D002452:Cell Count; D004064:Digestive System / Q000294:innervation; D006829:Hydra; D007150:Immunohistochemistry; D008959:Models, Neurological; D009415:Nerve Net / Q000033:anatomy & histology* / Q000737:chemistry / Q000254:growth & development; D009416:Nerve Regeneration / Q000502:physiology; D009474:Neurons / Q000737:chemistry / Q000166:cytology; D012100:Reproduction, Asexual / Q000502:physiology; D013194:Staining and Labeling; D014667:Vasopressins / Q000032:analysis*
chemical_list: D000911:Antibodies, Monoclonal; D014667:Vasopressins