The role of nerve growth factor in the regulation of collateral axon sprouting

Update Item Information
Title The role of nerve growth factor in the regulation of collateral axon sprouting
Publication Type dissertation
School or College College of Pharmacy
Department Pharmaceutics & Pharmaceutical Chemistry
Author Saffran, Bruce Nathan
Contributor Weingartner, Jean; Sunkara, Kusima; Muller, Yvonne
Date 1990-12
Description A fundamental question in neurobiology is to what extent the mammalian brain retains the ability to remodel neuronal connections throughout maturity. Although the mature brain is normally not permissive to extensive axonal growth, there are situations where the environment does become permissive to axonal remodeling. A current hypothesis to explain axonal remodeling suggests that the postsynaptic target and trophic signals derived therefrom contribute most to changes in axonal connectivity. Several authors have provided evidence that the signal eliciting such changes is the accumulation of trophic molecules, such as nerve growth factor (NGF), produced by a denervated target. One example of axonal remodeling within the mature mammalian brain is the collateral sprouting of uninjured sympathetic axons into the septal-denervated rat hippocampal formation. Considerable evidence supports the hypothesis that the accumulation of NGF within the hippocampal formation elicits sympathetic ingrowth. In this paper, I will review the evidence that trophic molecules are responsible for the initiation and maintenance of collateral sprouting phenomena in general, and the sympathohippocampal sprouting response in particular. I will then present two research reports that demonstrate that although intraventricular infusion of NGF fails to elicit sympathetic sprouting into the hippocampal formation, it dramatically increases the sympathetic innervation of the extracerebral vasculature. Furthermore, when NGF is infused at various times after sympathetic axons have been induced to grow into the brain by a medial septal lesion, intraventricular NGF infusion not only fails to enhance the sprouted projection but reduces the amount and delays the onset of such sprouting. I will then propose that changes in NGF levels, in the absence of injury, are sufficient to produce extensive remodeling of mature, sympathetic arbors; and that such remodeling may be based on competition between branches of the same neuron.
Type Text
Publisher University of Utah
Subject Neurology; Biochemistry
Subject MESH Nerve Growth Factor; Axons
Dissertation Institution University of Utah
Dissertation Name PhD
Language eng
Relation is Version of Digital reproduction of "The role of nerve growth factor in the regulation of collateral axon sprouting." Spencer S. Eccles Health Sciences Library. Print version of "The role of nerve growth factor in the regulation of collateral axon sprouting." available at J. Willard Marriott Library Special Collection. QP6.5 1990 .S24.
Rights Management © Bruce Nathan Saffran.
Format application/pdf
Format Medium application/pdf
Format Extent 2,476,924 bytes
Identifier undthes,5314
Source Original: University of Utah Spencer S. Eccles Health Sciences Library (no longer available).
Funding/Fellowship NIH grant NS 17131 to Keith A. Crutcher.
Master File Extent 2,476,951 bytes
ARK ark:/87278/s62f7qbf
Setname ir_etd
ID 191899
Reference URL https://collections.lib.utah.edu/ark:/87278/s62f7qbf
Back to Search Results