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Dynamique des représentations sensorielles| old_uid | 1861 |
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| title | Dynamique des représentations sensorielles |
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| start_date | 2006/11/30 |
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| schedule | 11h30 |
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| online | no |
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| summary | Odors evoke distributed dynamic glomerular activity patterns in the mammalian olfactory bulb (OB). While neurons downstream of sensory inputs respond to odorants with temporally structured activity, sensory inputs to glomeruli are typically described as static maps. Here we imaged the temporal dynamics of receptor neuron input to the OB with a calcium sensitive dye in the olfactory receptor nerve terminals in anesthetized mice. We found that diverse, glomerulus and odorant dependent temporal dynamics are present even at this initial input stage. Instantaneous spatial patterns of receptor neuron input to glomeruli changed both within and between respiration cycles. Significant changes of the odor evoked spatial patterns occur within the time window of 200 ms used by trained mice to discriminate odors. Glomerular odorant responses differed in amplitude, latency, rise time, and their degree of modulation by sniffing in an odorant specific manner. Pattern dynamics within the first respiration cycle recurred in a similar fashion during consecutive cycles. When sniff rate was increased artificially, pattern dynamics were preserved in the first sniff but were attenuated during subsequent sniffs. Temporal response properties were consistent across individuals on a coarse and on a fine scale of individual glomeruli. Latency and magnitude of glomerular inputs were only weakly correlated and might therefore convey independent odorant information. These data demonstrate that glomerular maps of primary sensory input to the OB are temporally dynamic. These dynamics may contribute to the representation of odorant information and affect information processing in the central olfactory system of rodents. |
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| responsibles | Berger |
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