Biology

Dr. Debanjan Dasgupta
Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London & Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK

Abstract:

Scene segmentation which is the capacity to differentiate between distinct parts of sensory flow is an important capacity of the mammalian brain. However, we largely fail to understand how our brain does it. We use olfaction as our model system to understand this specific problem. We found that temporal structure in odour stimulus helps to solve this problem. Correlation between odour plumes was observed to be an important cue to understand whether odours emerge from a single source or different sources. Further, we show that mice can use this aspect of the temporal structure to perform an odour source separation task. Eventually we interrogate the olfactory bulb neurons using in vivo electrophysiological techniques to understand if they have the capacity to follow different temporal features of the odour stimulus. A subset of the probed neurons were observed to be able to follow frequencies upto 20hz in the odour stimulus. Finally, pharmacologically blocking inhibition in the olfactory bulb altered the frequency following rule in a way that converted followers into non-followers and vice versa.

Overall, we conclude that mice are capable of perceiving temporal features of odour stimuli and is a probable mechanism by which animals perform odour scene segmentation. Further, neurons in the mouse olfactory bulb can encode aspects of the temporal structure of the odour stimulus.