Synapse formation involves multiple coordinated events between the presynaptic and the postsynaptic nerve that ultimately results in the expression of the appropriate neurotransmitters at the presynaptic nerve terminal and the matching neurotransmitter receptors on the opposing postsynaptic membrane. For my thesis research, I investigate different aspects of neurotransmitter receptor gene expression, an early step in the process of synaptogenesis. Specifically, I focus on two different neurotransmitter-gated ion channels that are expressed on neonatal rat peripheral neurons: the serotonin 5-HT3 receptor (5-HT3R) and the neuronal nicotinic acetylcholine receptor (nAChR). / The 5-HT3R is expressed on both nodose sensory neurons and sympathetic neurons. However, little is known about 5-HT3R expression during neonatal development or about the factors that regulate its expression. To investigate 5-HT3R gene expression, first I examined 5-HT 3R mRNA levels in nodose and sympathetic neurons as they develop in vivo and in culture. My results show that 5-HT 3R gene expression is differentially regulated in these two populations of neurons. In addition, I demonstrate that 5-HT3R gene expression in nodose neurons depends on target innervation and can be modulated by neurotrophins. / Neonatal sympathetic neurons express five different neuronal nAChR subunit genes. One unresolved issue is the contribution of these five subunits to nAChR function. To investigate this issue, I altered the expression of one nAChR subunit gene, alpha3, using transient transfection procedures. To do this, first I modified and optimized gene transfer procedures for sympathetic neurons, based on recombinant adenovirus vectors. sing this approach, I overexpressed sense and antisense alpha3 mRNA and investigated how the changes in alpha3 subunit expression affect ACh-evoked currents on cultured sympathetic neurons. I show that changes in alpha3 mRNA levels alter the magnitude of ACh-evoked current densities. My results indicate that alpha3 gene expression is rate-limiting for the assembly and insertion of nAChRs on sympathetic neurons. / Together, my results show that multiple mechanisms influence the expression neurotransmitter-gated ion channel genes on peripheral neurons.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.35052 |
| Date | January 1998 |
| Creators | Rosenberg, Madelaine. |
| Contributors | Cooper, Ellis (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001635529, proquestno: NQ44563, Theses scanned by UMI/ProQuest. |
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