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Evolution of mammalian neocortical development| old_uid | 17012 |
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| title | Evolution of mammalian neocortical development |
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| start_date | 2018/12/17 |
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| schedule | 16h |
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| online | no |
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| details | Invited by Henry Kennedy |
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| summary | The mammalian neocortex appeared through changes of the developmental programs of neurogenesis, neuronal migration and circuit assembly that diverged in mammalian, reptilian and avian brains. We are interested in the shared and distinct developmental processes and review recent comparative developmental and transcriptomic data to identify divergent features as key triggers neocortical evolution. We identified tangential migratory streams in the mammalian cortex that delivered novel populations of early generated glutamatergic neurons, but did not identify such tangentially migrating populations in the avian brain (1-3). We observed de novo generation of cortical neurons from fate restricted cortical progenitors that form the interhemispehric connections through the corpus callosum in mouse, but not in chick (4). We recognized secondary proliferative domains with novel progenitors with specific fate restrictions that increased neurogenesis (5-6). Modelling parameters and relative proportions of proliferative periods helped us to identify the key factors responsible for increase in mammalian brain size (7). Comparisons of transcriptomes from selected brain regions in various species revealed considerable divergence between cell populations with developmental homologies (8). As a consequence of the above changes, the mammalian dorsal pallium is unique; it is populated by diverse neuronal populations that are generated according to a strict temporal sequence, neurons are arranged into layers and radial modules that communicate between the two hemispheres. |
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| responsibles | Secrétariat SBRI |
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