ISSN:
1432-0878
Keywords:
Neuroendocrine structures
;
Gastropods
;
Ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Studies of possible neuroendocrine structures in the pulmonate gastropod Helisoma tenue show that cerebral fuchsinophilic neurons with electron-dense granules (mean diameter 1,500 Å) apparently release their secretory content in an “intercerebral commissure neurohemal area” near the mediodorsal bodies (MDB) or in the “median labial nerve neurohemal area”. The MDB cells have axon-like processes which branch and end at the cerebral surface, separated by a thin capsule from the cerebral fuchsinophilic cells. The presence of granules (mean diameter 800 Å) in the terminals of the MDB cells suggests cell body origin, distal transport and release of the granular secretory material. The secretory product may have an influence on cerebral fuchsinophilic neurons. Electron microscopy reveals the presence of granules of different sizes and densities in expanded neurites at the periphery of the intestinal nerve of the visceral ganglion which may indicate the presence of a neurohemal area. However, the granules in the intestinal nerve neurites and in the visceral ganglion fuchsinophilic cells are similar to granules found in the heart which also suggests that the granules may carry a neurotransmitter.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00335494
