Date of Award


Publication Type

Master Thesis

Degree Name



Biological Sciences

First Advisor

Zielinski, Barbara,


Biology, Neuroscience.




In this investigation, I have attempted to localize nitric oxide synthase NOS in the olfactory system of one of the most primitive vertebrates, sea lamprey (Petromyzon marinus, L.), to determine if olfactory NOS is an evolutionarily conserved trait. Initially, I used NADPH diaphorase histochemistry as a specific histochemical marker for NOS activity. To show that diaphorase staining was due to NOS activity, exogenous substances expected to increase or diminish NOS enzymatic activity were added to the diaphorase assay. The following treatment with L-arginine, the diaphorase staining intensity at the supranuclear region of the olfactory epithelium was enhanced indicating that the exogenous L-arginine had been utilized as a substrate by NOS. The staining intensity was unaffected by D-arginine, revealing stereo-specific activity of NOS. With N$\sp{\rm G}$-methyl-L-arginine treatment, the level of diaphorase staining remained unchanged, whereas following incubation with N$\omega$-nitro-L-arginine, the staining was reduced, implying that N$\omega$-nitro-L-arginine competitively inhibited NOS activity. Following treatment with EGTA, the staining diminished, suggesting that the calcium required for NOS activity had been chelated by EGTA. To localize NOS in the sea lamprey olfactory organ, immunocytochemical analysis was performed with an antibody against NOS. Strong correlation and colocalization of NOS-like immunoreactivity and diaphorase staining confirmed that NOS was localized in the olfactory organ, olfactory nerve and in the glomeruli of the olfactory bulb. Therefore, in the olfactory organ of one of the most primitive extant vertebrates, the sea lamprey, nitric oxide may be produced in a NADPH-dependent reaction catalized by NOS, and act as n messenger in the processing of olfactory information. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1994 .H67. Source: Masters Abstracts International, Volume: 34-02, page: 0668. Adviser: Barbara Zielinski. Thesis (M.Sc.)--University of Windsor (Canada), 1995.