Behavioural role and neural representation of temporal dynamics in sensory stimuli. (360G-Wellcome-110174_Z_15_Z)

The external world is not static but in a constant state of flux. To understand how the brain functions, we, therefore, must investigate how it extracts relevant information from dynamic, highly fluctuating sensory signals. Olfaction is an ideal modality with which to study this question. A key sense for nocturnal and crepuscular animals, such as laboratory rodents, the comparatively simple anatomy of the early olfactory system makes it highly accessible and tractable. Turbulent airflow creates a rich temporal structure in the intensity fluctuations of natural odour stimuli. Yet, how these dynamics are processed by the olfactory system and the extent to which it uses or ignores this information remains unknown. I have recently established quantitative behavioural tools, genetic and optogenetic manipulation of the early olfactory system, electrophysiological and imaging approaches in the awake behaving mouse, and the tools to measure and generate temporally fluctuating olfactory stimuli with high bandwidth. We will now combine these approaches to tackle key questions relating to the significance of natural dynamics for the coding of sensory stimuli. 1: What information is contained in the dynamics of natural olfactory stimuli?2: To what extent do neurons represent such dynamics? 3: How are stimulus dynamics used for behavioural tasks such as navigation? 4: What are the circuits and mechanisms that support, extract information from, or compensate for stimulus dynamics? My guiding hypothesis is that temporal dynamics and coherence of natural smells are decoded by the circuitry of the early olfactory system to extract information about distance, location and the nature of olfactory objects and scenes.