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Full-Text Articles in Physiology
The Effects Of Inhibiting Wnt Secretion And Activity On Cranial And Neural Development, Julie Louise Hulet
The Effects Of Inhibiting Wnt Secretion And Activity On Cranial And Neural Development, Julie Louise Hulet
Theses and Dissertations
Wnt signaling has been shown to have several roles in the development of sensory neurons, particularly in the ophthalmic portion of the trigeminal nerve. Many of these studies have relied on the conclusion that Wnt is necessary but not sufficient for the induction and maintenance of the neural precursor cells that develop in the ophthalmic placode. Wnt had been inhibited in the ophthalmic placode using a dominant negative t-cell factor (TCF) and resulted in the loss of Pax3 expression (indicative of undifferentiated placode cells) in all targeted cells, suggesting a loss of specification/commitment of these cells to the sensory neuron …
Regulation Of Sensory Neurogenesis In The Trigeminal Placode: Notch Pathway Genes, Pax3 Isoforms, And Wnt Ligands, Jason Samuel Adams
Regulation Of Sensory Neurogenesis In The Trigeminal Placode: Notch Pathway Genes, Pax3 Isoforms, And Wnt Ligands, Jason Samuel Adams
Theses and Dissertations
This dissertation is divided into three chapters, each discussing the study of different regulatory molecules involved in sensory neurogenesis occurring in the trigeminal placode. Chapter one is a spatiotemporal description of Notch pathway genes in chick opV placode by stage-specific expression analysis, showing expression of many Notch pathway genes and effectors in the opV placode. Notch pathway gene expression is primarily confined to the ectoderm with highest expression of these genes at the beginning stages of peak neuronal differentiation. This information preceded studies of the functional roles that Notch signaling has in the opV placode and how it may affect …
Function Of The Notch/Delta Pathway In Ophthalmic Trigeminal Placode Development, Matthew K. Ball
Function Of The Notch/Delta Pathway In Ophthalmic Trigeminal Placode Development, Matthew K. Ball
Theses and Dissertations
The ophthalmic trigeminal placode (opV) is the birth place of one cell type of sensory neurons contributing to the trigeminal ganglion. Signals from the neural tube induce placodal identity within the surface ectoderm. Specified opV placode cells then up-regulate neuron differentiation markers and migrate to the ganglion. Several molecular pathways have been shown to act in opV placode cell development. Despite this, signals that specify individual neurons from within the opV placode remain unknown. However, it is known that components of the Notch signaling pathway are expressed in the opV placode. I tested the role of Notch signaling in opV …
The Role Of Wnt Signaling In Development Of The Ophthalmic Trigeminal Placode., Rhonda Nicole Lassiter
The Role Of Wnt Signaling In Development Of The Ophthalmic Trigeminal Placode., Rhonda Nicole Lassiter
Theses and Dissertations
Cranial placodes are ectodermal regions that contribute extensively to the vertebrate peripheral nervous system. The development of the ophthalmic trigeminal (opV) placode, which gives rise only to sensory neurons of the ophthalmic lobe of the trigeminal ganglion, is a well-studied model of sensory neuron development. While key differentiation processes have been characterized at the tissue and cellular levels, the molecules governing opV placode development have not been well described. This study identifies the canonical Wnt signaling pathway as a regulator of opV trigeminal placode development. Introducing dominant-negative TCF and dominant-active β-catenin expression constructs by in ovo electroporation, we have manipulated …
The Role Of Pax3 In Neuronal Differentiation Of The Ophthalmic (Opv) Trigeminal Placode And Neural Tube During Chicken Embryonic Development, James R. Bradshaw
The Role Of Pax3 In Neuronal Differentiation Of The Ophthalmic (Opv) Trigeminal Placode And Neural Tube During Chicken Embryonic Development, James R. Bradshaw
Theses and Dissertations
Pax3 has been used as a valuable marker in research aimed at understanding tissue interactions involved in trigeminal ophthalmic (opV) placode development. While Pax3 expression coincides with opV neuron specification, the function of Pax3 in these cells has not previously been investigated. Splotch mutant mice (which lack Pax3) have a reduced trigeminal ganglion; however it is not clear whether this reduction is due to neural crest or placode cells. We have used electroporation in the chick model system to block or ectopically express Pax3 at key times in opV placode development. Using several markers of placode cell differentiation, we have …