Insulin-like growth factor I induced survival of axotomized olfactory neurons in the chick.
Insulin-like growth factor 1 (IGF1) receptor is expressed in avian olfactory neurons and IGF1 in the bulb. To explore the function of IGF1 in olfactory system in the chick, we infused IGF1 at the lesion site 0 and 12 h after olfactory axotomy. The animals were killed 1-3 days later. TdT mediated dUTP nick end labeling method and bromodeoxyuridine incorporation allowed the evaluation of programmed cell death and mitotic activity respectively in the olfactory epithelia of IGF1 treated or untreated lesioned animals and controls. IGF1 treatment suppressed the apoptotic wave, stimulated mitosis which peaked within 24 h (instead of 48 h), to return promptly to normal, and transiently maintained the number of calmodulin related kinase II expressing neurons at normal levels. It reveals a long lasting effect of IGF1 on the survival of lesioned olfactory neurons and transient effects on maintenance of differentiation and mitosis stimulation.
Mathonnet
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UMR-CNRS 6101-Faculté de Médecine, 2 rue du Dr Marcland, 87025 Limoges, cedex, France.
Comte
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Lalloué
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Ayer-Le Lièvre
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C
D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D019771:Axotomy; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects* / Q000502:physiology; D002642:Chick Embryo / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000378:metabolism / Q000494:pharmacology*; D008938:Mitosis / Q000187:drug effects* / Q000502:physiology; D009416:Nerve Regeneration / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009831:Olfactory Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012183:Retrograde Degeneration / Q000188:drug therapy / Q000378:metabolism / Q000517:prevention & control; D013997:Time Factors
D007334:Insulin-Like Growth Factor I