Function of Differentially Expressed Intracellular Calcium Channels in Retinal Neurons

Simple item page
dc.contributor.advisorPeter Koulen
dc.contributor.committeeMemberRaghu Krishnamoorthy
dc.contributor.committeeMemberRong Ma
dc.creatorNixon, Everett Sheldon
dc.date.accessioned2019-08-22T21:24:41Z
dc.date.available2019-08-22T21:24:41Z
dc.date.issued2008-05-01
dc.date.submitted2013-11-05T06:54:04-08:00
dc.description.abstractNixon, Everett, Function of differentially expressed intracellular calcium channels in retinal neurons. Doctor of Philosophy (Pharmacology and Neuroscience), May, 2008, pp154, 17 illustrations. The retina, a specialized part of the central nervous system (CNS) is the innermost layer of the eye responsible for capturing light and converting the light response into a signal that can be transmitted through the optic nerve and onto the brain for interpretation. The ability of the retina to perceive light is dependent on its sensory neurons and the neural circuitry present that initiate the primary stage of processing the image being visualized, which then transmits an electrical signal down the optic nerve to the brain for processing and ultimately visual perception. In the vertical pathway of the visual process that involves the photoreceptor cells, bipolar cells and the ganglion cells, glutamate is the main excitatory neurotransmitter. Communication between these cells is dependent upon the release of glutamate into the synaptic region within both the outer plexiform layer and inner plexiform layer, a process that is Ca2+ regulated. In neurons, Ca2+ regulates a plethora of processes such as gene expression, cell death, synaptic plasticity and neurotransmitter release since it serves as a critical intracellular messenger. In view of the involvement of Ca2+ in a variety of physiological processes, it is essential for the intracellular Ca2+ concentration to be tightly regulated within neuronal cell. Regulation of Ca2+ signaling within retinal neurons can occur via inositol 1,4,5-triphosphate (IP3) receptors (IP3Rs) and ryanodine receptors (RyRs). These receptors are involved in the release of Ca2+ from the intracellular stores such as the endoplasmic reticulum (ER) into the cytosol. IP3Rs and RyRs contribute substantially to cytosolic free Ca2+ concentration transients and thereby play an important role in neuronal function. The purpose of the study was to determine the role of mGluRs, IP3Rs and RyRs in increasing intracellular Ca2+ levels in retinal neurons as related to signaling and neurotransmitter release. The present study provides experimental evidence for the following mechanisms: -Activation of mGluR8 in photoreceptor cells reduced cytosolic Ca2+ concentration by inhibition of the voltage gated Ca2+ channels on the plasma membrane. –The distribution of IP3R and RyR isoforms was associated with cytosolic Ca2+ transients and the IP3R induced transients occurs by activation of group I mGluRs. –In rod bipolar cells, the main increase in cytosolic Ca2+ concentrations during depolarization is due to Ca2+ release from internal stores via activation of RyR. The results of the present study contribute to the understanding of intracellular Ca2+ signaling in retinal neurons and Ca2+ signaling mechanisms. This is of relevance for identifying mechanisms controlling neurotransmitter release and possible pharmacological targets in neurodegenerative retinal diseases characterized by Ca2+ dyshomeostasis.
dc.format.mimetypeapplication/pdf
dc.identifier.urihttps://hdl.handle.net/20.500.12503/29312
dc.language.isoen
dc.provenance.legacyDownloads0
dc.subjectBiology
dc.subjectCell and Developmental Biology
dc.subjectCell Biology
dc.subjectCells
dc.subjectEye Diseases
dc.subjectLife Sciences
dc.subjectMedical Anatomy
dc.subjectMedical Physiology
dc.subjectMedicine and Health Sciences
dc.subjectOphthalmology
dc.subjectOptometry
dc.subjectVision Science
dc.subjectIntracellular calcium channels
dc.subjectretinal neurons
dc.subjectretina
dc.subjectcentral nervous system
dc.subjectCa2+
dc.subjectryanodine receptors
dc.subjectendoplasmic reticulum
dc.titleFunction of Differentially Expressed Intracellular Calcium Channels in Retinal Neurons
dc.typeDissertation
dc.type.materialtext
thesis.degree.departmentGraduate School of Biomedical Sciences
thesis.degree.disciplinePharmacology and Neuroscience
thesis.degree.grantorUniversity of North Texas Health Science Center at Fort Worth
thesis.degree.nameDoctor of Philosophy

Files

Original bundle

Now showing 1 - 1 of 1
Thumbnail Image
Name:
Nixon_FunctionOfDifferentiallyExpressed.pdf
Size:
54.93 MB
Format:
Adobe Portable Document Format
Download

Collections

School of Biomedical Sciences
Theses and Dissertations