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Fine structure of nerve cells in a planarian
Author(s) -
Lentz Thomas L.
Publication year - 1967
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1051210406
Subject(s) - golgi apparatus , biology , endoplasmic reticulum , neuropil , vesicle , microbiology and biotechnology , cytoplasm , planarian , synaptic vesicle , granule (geology) , cell type , free nerve ending , ribosome , anatomy , cell , central nervous system , neuroscience , biochemistry , rna , regeneration (biology) , membrane , paleontology , gene
The fine structure of the nerve cell types in the white planarian Procotyla fluviatilis were described. Ganglion cells comprise the major portion of the brain. These cells are irregular in shape with several cytoplasmic processes and contain ribosomes, a sparse endoplasmic reticulum, microtubules, lysosomes, and a Golgi apparatus with numerous small vesicles. Granule‐containing cells are situated in the peripheral regions of the brain and along the nerve cords. These cells contain ribosomes, rough‐surfaced endoplasmic reticulum and a Golgi apparatus with associated dense granules. The granules occupy most of the cytoplasm and are ∼ 750A in diameter with moderately dense contents, ∼ 750A with opaque contents, and ∼ 1000A with contents of medium density. These granules are similar to those in the nervous systems of higher animals that contain epinephrine, norepinephrine, and neurosecretory substance, respectively. Each cell contains predominantly one type of granule although there is some intermixing of granules and intermediate types between the three most abundant granules. Small clear vesicles, resembling cholinergic synaptic vesicles, and all types of dense granules occur in the neuropil and within nerve endings.