ULTRASTRUCTURE OF AND MONOAMINE LOCATION IN CULTURED HUMAN FETAL SYMPATHETIC NEURONS.
Item
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Title
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ULTRASTRUCTURE OF AND MONOAMINE LOCATION IN CULTURED HUMAN FETAL SYMPATHETIC NEURONS.
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Identifier
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AAI8401966
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identifier
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8401966
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Creator
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ZEEVALK, GAIL KATHLEEN DUFFY.
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Contributor
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Katherine M. Lyser
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Date
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1983
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, General
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Abstract
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Dissociated human fetal sympathetic neurons were cultured in a defined medium for 5 to 40 days. The effects of serum-free conditions on several neuronal features were examined by phase contrast and electron microscopy. Serum grown cultures and in vivo ganglia were studied for comparison.;Neurons cultured in defined or serum-supplemented medium attached readily to the culture dish and extended extensive neurites. In contrast to the dense outgrowth in serum-supplemented medium, few nonneuronal cells were present in defined medium. The fine structure of the neurons in defined medium was similar to that of neurons in vivo or in serum-supplemented medium. While a developmental range of cells from very immature cells to more mature young neurons was found at all time points examined, there appeared to be a larger proportion of the more mature neurons in older cultures. Very immature cells had condensed chromatin and scanty cytoplasm while more mature neurons showed more dispersed karyoplasm and a developmentally advanced organelle population. The ultrastructure of the neurites was typical of sympathetic axons. Varicosities and occasional synapses were found in cultures maintained for at least 20 days. It is concluded that the defined medium used here allows the expression of typical neuronal cytology, neurite extension and synapse formation.;The physiological differentiation of these cultured neurons with respect to neurotransmitter production and storage was examined ultrastructurally by chromate-dichromate cytochemistry. Chromate-dichromate specifically reacts with monoamines to result in an electron dense precipitate. Reaction product resembling the cores of dense core vesicles and with a size range compatible with them (50-94 nm) was seen in all chromate-dichromate treated cultures. Positive vesicles were found in somas as well as processes and occurred either singly or in small clusters. Clusters of large dense core vesicles were seen more frequently in older cultures. Small dense core vesicles were never found. These findings demonstrate the ability of human fetal sympathetic neurons to retain an adrenergic phenotype in vitro and to store their neurotransmitter in large dense core vesicles.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Biology
