Publicação
The contribution of odor induced activity to adult neurogenesis : behavioural and morphological consequences of the different learning contexts
| Resumo: | The Olfactory Bulb (OB) is the first relay of the main olfactory system. In the OB, newborn neurons coming from the subventricular zone differentiate into interneurons and integrate mainly in the granule cell layer. Bulbar neurogenesis is an activity dependent process that is modulated by odors. Notably, odor learning in a critical time window is able to increase neurogenesis in the OB, but whether odor exposure or learning per se shape neurogenesis is not clearly understood. To clarify this question, we tested the effect on adult neurogenesis of olfactory associative learning versus auditory associative learning (i.e. a different sensory modality) versus passive exposure to odorants versus control animals. Using these four experimental contexts of sensory stimulation, we then investigated the consequences on the number and the cell morphology of a cohort of newborn cells labelled with BrdU and GFP. Using BrdU, no difference was observed between conditions whereas using GFP, the olfactory learning condition had a significant increase in the number of cells when compared with auditory learning. Modest increase in cell survival was also observed after odor exposure and auditory learning. Morphological analysis revealed a reduced main dendrite length after odor learning. This study suggests that olfactory exposure and the process of learning per se cooperate to boost the survival and the integration of newborn neurons into the OB. |
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| Autores principais: | Vieira, Inês Sofia Silva, 1989- |
| Assunto: | Bulbo olfactivo Neurogénese bulbar Novos neurónios Aprendizagem Morfologia Teses de mestrado - 2012 |
| Ano: | 2012 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | The Olfactory Bulb (OB) is the first relay of the main olfactory system. In the OB, newborn neurons coming from the subventricular zone differentiate into interneurons and integrate mainly in the granule cell layer. Bulbar neurogenesis is an activity dependent process that is modulated by odors. Notably, odor learning in a critical time window is able to increase neurogenesis in the OB, but whether odor exposure or learning per se shape neurogenesis is not clearly understood. To clarify this question, we tested the effect on adult neurogenesis of olfactory associative learning versus auditory associative learning (i.e. a different sensory modality) versus passive exposure to odorants versus control animals. Using these four experimental contexts of sensory stimulation, we then investigated the consequences on the number and the cell morphology of a cohort of newborn cells labelled with BrdU and GFP. Using BrdU, no difference was observed between conditions whereas using GFP, the olfactory learning condition had a significant increase in the number of cells when compared with auditory learning. Modest increase in cell survival was also observed after odor exposure and auditory learning. Morphological analysis revealed a reduced main dendrite length after odor learning. This study suggests that olfactory exposure and the process of learning per se cooperate to boost the survival and the integration of newborn neurons into the OB. |
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