Odorant organization in the olfactory bulb of the sea lamprey.
Olfactory sensory neurons innervate the olfactory bulb, where responses to different odorants generate a chemotopic map of increased neural activity within different bulbar regions. In this study, insight into the basal pattern of neural organization of the vertebrate olfactory bulb was gained by investigating the lamprey. Retrograde labelling established that lateral and dorsal bulbar territories receive the axons of sensory neurons broadly distributed in the main olfactory epithelium and that the medial region receives sensory neuron input only from neurons projecting from the accessory olfactory organ. The response duration for local field potential recordings was similar in the lateral and dorsal regions, and both were longer than medial responses. All three regions responded to amino acid odorants. The dorsal and medial regions, but not the lateral region, responded to steroids. These findings show evidence for olfactory streams in the sea lamprey olfactory bulb: the lateral region responds to amino acids from sensory input in the main olfactory epithelium, the dorsal region responds to steroids (taurocholic acid and pheromones) and to amino acids from sensory input in the main olfactory epithelium, and the medial bulbar region responds to amino acids and steroids stimulating the accessory olfactory organ. These findings indicate that olfactory subsystems are present at the base of vertebrate evolution and that regionality in the lamprey olfactory bulb has some aspects previously seen in other vertebrate species.
Department of Biological Sciences, University of Windsor, Windsor, ON, Canada N9B3P4.
Warren W
WW
Green
Department of Biological Sciences, University of Windsor, Windsor, ON, Canada N9B3P4.
Karl
K
Boyes
Department of Biological Sciences, University of Windsor, Windsor, ON, Canada N9B3P4.
Charrie
C
McFadden
Groupe de Recherche en Activité Physique Adaptée, Département des sciences de l'activité physique, Université du Québec à Montréal, Montréal, QC, Canada H3C3P8.|Groupe de Recherche sur le Système Nerveux Central, Département de neurosciences, Université de Montréal, Montréal, QC, Canada H3C3J7.
Gheylen
G
Daghfous
Groupe de Recherche en Activité Physique Adaptée, Département des sciences de l'activité physique, Université du Québec à Montréal, Montréal, QC, Canada H3C3P8.|Groupe de Recherche sur le Système Nerveux Central, Département de neurosciences, Université de Montréal, Montréal, QC, Canada H3C3J7.
François
F
Auclair
Department of Biological Sciences, University of Windsor, Windsor, ON, Canada N9B3P4.
Huiming
H
Zhang
Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824, USA.
Weiming
W
Li
Groupe de Recherche en Activité Physique Adaptée, Département des sciences de l'activité physique, Université du Québec à Montréal, Montréal, QC, Canada H3C3P8.|Groupe de Recherche sur le Système Nerveux Central, Département de neurosciences, Université de Montréal, Montréal, QC, Canada H3C3J7.
Réjean
R
Dubuc
Department of Biological Sciences, University of Windsor, Windsor, ON, Canada N9B3P4 zielin1@uwindsor.ca.|Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada N9B3P4.
Barbara S
0000-0002-5666-4477
BS
Zielinski
D000818:Animals; D009812:Odorants / Q000032:analysis; D009830:Olfactory Bulb / Q000033:anatomy & histology / Q000502:physiology / Q000648:ultrastructure; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D048428:Petromyzon / Q000033:anatomy & histology* / Q000502:physiology*; D012903:Smell
Chemotopy; Neurophysiology; Odour responses; Tract tracing