The regulation of NGFmRNA in the rodent central nervous system.
Item
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Title
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The regulation of NGFmRNA in the rodent central nervous system.
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Identifier
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AAI9207081
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identifier
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9207081
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Creator
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Hellendall, Ronald Peter.
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Contributor
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Adviser: Mariann Blum
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Date
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1991
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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, Neuroscience
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Abstract
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Recent evidence has indicated a role for nerve growth factor (NGF) in the central nervous system (CNS). The observation that a population of cholinergic cells in the CNS can respond to NGF and that similar cells undergo profound degeneration in Alzheimer's disease has provoked interest in the role and regulation of NGF in the CNS. While evidence supports a neuronal expression of NGF mRNA in the intact adult brain, recent reports demonstrate that other cells found in the CNS have the capacity to express NGF. The finding that Schwann cells in the peripheral nervous system can produce NGF during development and subsequent to injury indicates that the elaboration of trophic factors by glia may play a role in the survival of neurons. Studies were conducted to determine if glia in the CNS can also express this growth factor. High levels of NGF mRNA were found in enriched astrocyte cultures derived from hippocampus, cerebral cortex, hypothalamus, and cerebellum of the neonatal rat brain. A trend toward lower NGF mRNA levels was found when cultures from cerebral cortex were maintained for 25 days in vitro. Interleukin-1 (IL-1), a cytokine released by phagocytic cells and shown previously to induce NGF mRNA in the sciatic nerve, significantly increased NGF mRNA in astrocyte cultures from a variety of CNS regions. This induction was not observed in the 25 day cultures nor were NGF mRNA levels changed in whole hippocampus when IL-1 was injected in the lateral ventrical of adult male rats. These data indicate a role for astrocyte released NGF during specific stages of development of the CNS and suggest a maturational effect where astrocytes no longer provide trophic support for neurons and NGF is primarily expressed in neurons in the adult. The absence of NGF mRNA induction following IL-1 injection in the adult indicates the mature CNS may lack a population cells able to regulate NGF expression in response to trauma. Lack of trophic support may be a component in the inability of CNS neurons to regrow subsequent to injury.
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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.
