Morphological and physiological studies of the primary olfactory pathway in the sea lamprey, Petromyzon marinus: Spatial organization of discrete glomerular subsets and the development of functional imaging for monitoring glomerular activity.
Date of Award
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Olfaction is an extremely important communication modality for most organisms, yet it is probably the sensory system least understood. Recent findings have shed light on some of the basic principles that control olfactory detection and transmission of signals into the central nervous system, but the mechanisms for spatial resolution of odorants within the brain are still poorly understood. In this study we have used histological, immunocytochemical and in vivo optical imaging techniques to investigate the spatial and functional organization of olfactory bulb glomeruli of the developing Agnathan, the sea lamprey, Petromizon marinus. We characterized the glomerular pattern of olfactory sensory neuron terminals in the brain, and found discrete subsets of olfactory glomeruli. The 45 kD protein G olf, a cAMP dependent GTP binding protein, was localized in the dorsal, anterior, lateral and ventral glomeruli, but was absent from medial glomeruli. This result shows that Golf expression was present during early vertebrate evolution and is fundamental to the function of a subpopulation of vertebrate olfactory sensory neurons. We pursued the goal of combining physiological and morphological analysis of defined axonal projections by developing a preparation of the pathway of olfactory sensory axons for dynamic optical imaging. The larval stage of the lamprey provides a very powerful model, allowing for view of the entire olfactory pathway since olfactory epithelium, nerves and olfactory bulb are located in the same horizontal plane. Using a calcium indicator (Ca2+green 1-dextran), we anterogradely labeled the glomeruli, and observed pre-synaptic activity following potassium induced synchronous depolarization and olfactory stimulation with the basic amino acid L-arginine. This study established the lamprey as an appropriate model for examining spatial and temporal events during olfactory coding.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .F76. Source: Masters Abstracts International, Volume: 41-04, page: 1024. Adviser: Barbara Zielinski. Thesis (M.Sc.)--University of Windsor (Canada), 2002.
Frontini, Andrea., "Morphological and physiological studies of the primary olfactory pathway in the sea lamprey, Petromyzon marinus: Spatial organization of discrete glomerular subsets and the development of functional imaging for monitoring glomerular activity." (2002). Electronic Theses and Dissertations. 2783.