The alarm reaction in crucian carp is mediated by olfactory neurons with long dendrites.
In the present study, we applied a lipophilic tracer, Dil (1,1-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate), to the synaptic region of the medial olfactory bulb in formaldehyde-fixed preparations from the crucian carp. We observed staining both in the axons of secondary neurons leading to the brain and in the olfactory receptor neurons (ORNs) of the olfactory epithelium. In those preparations, where staining of the tract was restricted to axons of the medial part of the medial olfactory tract, the majority (86-98%) of the somata of the sensory neurons were found in the deep layers of olfactory epithelium. Since the medial bundle of the medial olfactory tract mediates alarm behaviour in the crucian carp, we conclude that the sensory neurons with long dendrites participate in the reception of alarm pheromones.
Hamdani
El Hassan
el H
Division of General Physiology, Department of Biology, PO Box 1051, University of Oslo, N-0316 Oslo, Norway.
Døving
Kjell B
KB
D000818:Animals; D001369:Axons / Q000502:physiology; D002232:Carbocyanines; D002347:Carps / Q000502:physiology*; D004396:Coloring Agents; D015342:DNA Probes; D004848:Epithelium / Q000502:physiology; D005456:Fluorescent Dyes; D006651:Histocytochemistry; D016501:Neurites / Q000502:physiology* / Q000648:ultrastructure; D009830:Olfactory Bulb / Q000502:physiology / Q000648:ultrastructure; D009833:Olfactory Pathways / Q000502:physiology / Q000648:ultrastructure; D018034:Olfactory Receptor Neurons / Q000502:physiology* / Q000648:ultrastructure
D002232:Carbocyanines; D004396:Coloring Agents; D015342:DNA Probes; D005456:Fluorescent Dyes; C024286:3,3'-dioctadecylindocarbocyanine