Grant: Discovery Grants Program - Individual

The sense of smell plays a vital role for some species, allowing them to find food, detect potential threats, and interact with conspecifics. Animals encounter new odours every day. To detect these new odours, they need to detect and then discriminate them from previously experienced and ambient odours. Among the structures involved, the olfactory bulb is pivotal as it represents the first relay of odour information processing. Interestingly, the olfactory bulb, unlike most other brain regions, retains the ability to replace some of its neuronal population in adulthood by constantly integrating new cells through a process called adult neurogenesis. This constant replenishment of neuronal populations in the brain region which is crucial for odour information processing, poses a "stability-plasticity" dilemma in that the normal functioning of the olfactory bulb network must be maintained despite its constant and substantial structuro-functional reorganization. What is the function of these adult-born neurons and are they involved in the odour information processing in a manner that cannot be accomplished by early-born interneurons? Our long-term goals are to uncover the role of adult-born neurons in the olfactory bulb and to elucidate why the bulbar network needs this constant supply of new neurons throughout the life of animals. Our overarching hypothesis is that adult-born neurons represent a reservoir of very plastic cells that allow for the discrimination and learning of new complex odours in the constantly changing sensory environment, while early-born neurons process basic olfactory functions and previously learned, stable odour memory traces. According to this hypothesis, early-born neurons provide "stability" in the bulbar network and process vital odour information, while adult-born bulbar neurons provide "plasticity" and make it possible to learn new sensory stimuli in constantly changing environmental conditions. We have designed a series of experiments to test this hypothesis and to uncover the mystery of constant neuronal replacement in the adult olfactory bulb. We will use state-of-the-art imaging approaches to track neuronal replacement in vivo as well as tools to record and manipulate neuronal activity to probe the roles of early-born and adult-born neurons during different olfactory tests. Impact: Our experiments will make it possible to better understand why and how the adult brain produces and incorporates new neurons into already existing functional circuits of the olfactory bulb and what these new neurons do in the olfactory network. HQP training: Our research program will allow for the training of highly qualified personnel (HQP) who will be proficient in different research fields. They will perform their scientific research in an equitable, diverse, and inclusive lab environment where each and every trainee feels welcome.