title: Morphological and electrophysiological examination of olfactory sensory neurons during the early developmental prolarval stage of the sea lamprey Petromyzon marinus L.
abstract: This study examined olfactory sensory neuron morphology and physiological responsiveness in newly hatched sea lamprey, Petromyzon marinus L. These prolarvae hatch shortly after neural tube formation, and stay within nests for approximately 18 days, before moving downstream to silty areas where they burrow, feed and pass to the larval stage. To explore the possibility that the olfactory system is functioning during this prolarval stage, morphological and physiological development of olfactory sensory neurons was examined. The nasal cavity contained an olfactory epithelium with ciliated olfactory sensory neurons. Axons formed aggregates in the basal portion of the olfactory epithelium and spanned the narrow distance between the olfactory epithelium and the brain. The presence of asymmetric synapses with agranular vesicles within fibers in the brain, adjacent to the olfactory epithelium suggests that there was synaptic connectivity between olfactory sensory axons and the brain. Neural recordings from the surface of the olfactory epithelium showed responses following the application of L-arginine, taurocholic acid, petromyzonol sulfate (a lamprey migratory pheromone), and water conditioned by conspecifics. These results suggest that lampreys may respond to olfactory sensory input during the prolarval stage.
authors.affiliation: Department of Biological Sciences, University of Windsor, Windsor, Ontario, Canada, N9B 3P4. Zielin1@uwindsor.ca
authors.forename: Barbara S
authors.initials: BS
authors.lastname: Zielinski
authors.forename: Kim
authors.initials: K
authors.lastname: Fredricks
authors.forename: Rod
authors.initials: R
authors.lastname: McDonald
authors.forename: Aliya U
authors.initials: AU
authors.lastname: Zaidi
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology; D002756:Cholagogues and Choleretics / Q000494:pharmacology; D002793:Cholic Acids / Q000494:pharmacology; D004594:Electrophysiology; D004625:Embryo, Nonmammalian / Q000502:physiology; D005260:Female; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009831:Olfactory Mucosa / Q000166:cytology / Q000196:embryology / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000196:embryology* / Q000502:physiology* / Q000648:ultrastructure; D048428:Petromyzon / Q000196:embryology* / Q000502:physiology; D013656:Taurocholic Acid / Q000494:pharmacology
chemical_list: D002756:Cholagogues and Choleretics; D002793:Cholic Acids; C500317:petromyzonol sulfate; D013656:Taurocholic Acid; D001120:Arginine