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Full-Text Articles in Life Sciences
Glia Delimit Shape Changes Of Sensory Neuron Receptive Endings In C. Elegans, Carl Procko
Glia Delimit Shape Changes Of Sensory Neuron Receptive Endings In C. Elegans, Carl Procko
Student Theses and Dissertations
Neuronal receptive endings such as dendritic spines and sensory protrusions are structurally remodeled by experience. How receptive endings acquire their remodeled shapes is not well understood. In response to environmental stressors, including starvation, crowding and high temperature, the nematode Caenorhabditis elegans enters a diapause state, termed dauer, which is accompanied by remodeling of sensory neuron receptive endings. Here, we demonstrate that sensory receptive endings of the AWC amphid neurons in dauer animals remodel in the confines of a compartment defined by the amphid sheath glial cells that envelop these endings. The glia remodel concomitantly with and independently of AWC receptive …
Regulation Of Polarized Protein Transport To Axons, Dendrites, And Sensory Cilia In Caeborhabditis Elegans Neurons, Tapan Apurva Maniar
Regulation Of Polarized Protein Transport To Axons, Dendrites, And Sensory Cilia In Caeborhabditis Elegans Neurons, Tapan Apurva Maniar
Student Theses and Dissertations
Neurons are highly polarized cells, capable of receiving, processing and transmitting information, with the help of their specialized domains, an axon and one or more dendrites. The molecular dissimilarities between these domains are critical for neuronal function, and are a result of asymmetric trafficking of a large number of cellular components including ion channels, neurotransmitter receptors, synaptic vesicles, and signaling proteins. Yet, despite the significance of asymmetric protein transport in neuronal polarity, the molecules and mechanisms that direct polarized transport to axons, dendrites and cilia in neurons are only partly understood. In this thesis, I describe my effort at understanding …
Dre-1/Fbxo11, A Conserved F Box Protein, Regulates Apoptosis In C. Elegans And Is Mutated In Human Lymphoma, Michael Chiorazzi
Dre-1/Fbxo11, A Conserved F Box Protein, Regulates Apoptosis In C. Elegans And Is Mutated In Human Lymphoma, Michael Chiorazzi
Student Theses and Dissertations
In the course of metazoan embryonic and post-embryonic development, more cells are generated than exist in the mature organism, and these cells are deleted by the process of programmed cell death. In addition, cells can be pushed toward death when they accumulate genetic errors, are virally-infected or are otherwise deemed potentially-harmful to the overall organism. Caenorhabditis elegans has proved to be an excellent model system for elucidating the genetic underpinnings of cell death, and research has shown that the core machinery, made up of the egl-1, ced-9, ced-4 and ced-3 genes, is conserved across metazoans, and their homologues are crucial …
The Long-Rage Directional Behavior Of The Nematode C. Elegans, Margherita Peliti
The Long-Rage Directional Behavior Of The Nematode C. Elegans, Margherita Peliti
Student Theses and Dissertations
Like any mobile organism, C. elegans relies on sensory cues to find food. In the absence of such cues, animals might display defined search patterns or other stereotyped behavior. The motion of C. elegans has previously been characterized as a sinusoid whose direction can be modulated by gradual steering or by sharp turns, reversals and omega bends. However, such a fine-grained behavioral description does not by itself predict the longrange features of the animals’ pattern of movement. Using large (24 cm x 24 cm) Petri dishes, we characterized the movement pattern of C. elegans in the absence of stimuli. To …
Mechanisms Of Presynaptic Cav2 Calcium Channel Localization In Caenorhabditis Elegans, Yasunori Saheki
Mechanisms Of Presynaptic Cav2 Calcium Channel Localization In Caenorhabditis Elegans, Yasunori Saheki
Student Theses and Dissertations
Neurotransmitter release at nerve terminals is a fundamental aspect of communication in the nervous system. Voltage changes in the presynaptic membrane are sensed by presynaptic voltage-gated calcium channels that mediate calcium influx at the nerve terminals to execute exocytosis of various kinds of neurotransmitters. Defects in presynaptic calcium channels lead to many neurological disorders, emphasizing the importance of these channels in the regulation of neuronal activities in the brain. Previous physiological studies have focused on opening kinetics of the channels and their modulation by auxiliary subunits. Cell biological questions such as trafficking and clustering of the channels at the presynaptic …
Mechanisms For Maintaining Cell Identity In C.Elegans Olfactory Neurons, Bluma J. Lesch
Mechanisms For Maintaining Cell Identity In C.Elegans Olfactory Neurons, Bluma J. Lesch
Student Theses and Dissertations
Maintenance of cell identity is a complex process that depends on developmentally determined transcriptional states and on environmental input. In neurons, which are both highly differentiated and highly sensitive to external stimuli, maintenance of identity is especially challenging. In this thesis, I describe the isolation and characterization of several genes involved in maintaining the identities of two olfactory neuron subtypes, AWCON and AWCOFF, in the nematode Caenorhabditis elegans. The AWCON and AWCOFF identities are specified by a stochastic decision during embryogenesis, but several of the genes involved in this embryonic decision are subsequently downregulated. Additional mechanisms must therefore act to …
The Neural Circuitry Of Social Behavior In C. Elegans, Evan Z. Macosko
The Neural Circuitry Of Social Behavior In C. Elegans, Evan Z. Macosko
Student Theses and Dissertations
Most animal species, from simple invertebrates to complex mammals, require behavioral mechanisms to communicate with and respond to conspecifics, whether to mate, to assess predatory danger, or evaluate the nutritional quality of the surrounding environment. Understanding the molecular and cellular underpinnings of these social behaviors remains a central challenge in neurobiology. I used the nematode C. elegans as a model system to study the genetics and neural circuitry that underlie social behavior. First, I evaluated the behavioral responses of C. elegans to a nematode extract (deathmone), which served as a model for alarm pheromones in other animal species (chapter 2). …
Glia Are Required For Sensory Neuron Morphology And Function In Caenorhabditis Elegans, Taulant Bacaj
Glia Are Required For Sensory Neuron Morphology And Function In Caenorhabditis Elegans, Taulant Bacaj
Student Theses and Dissertations
The nervous system emerges from the coordinated development of neurons and glia. To better understand the processes that enable nervous system development and function we have studied the sensory organs of Caenorhabditis elegans because their anatomy and function are well-characterized. Specifically, we have focused on two aspects of sensory organs: how do glia interact with neurons to enable proper development and function and how are sensory cilia generated. To uncover any glial roles, we ablated the major glial cell of the amphid sensilla. Embryonic glial ablation did not affect neuronal survival and resulted in sensory neuron dendrites that were far …