Odour delivery

To present odour stimuli in a controlled and temporally precise manner, we developed a high-speed odour delivery device ("tODD", Ackels et al., 2021). Temporally complex odour plumes of different chemical identity, concentration and across a range of temporal profiles are presented to animals. Mice are, for example, head-fixed on a treadmill where we record the animal's respiration profile to present odour stimuli precisely during a particular time of the respiration cycle, typically triggered to the start inhalation.

We use dual-color 2-Photon Ca²⁺ imaging and extracellular probes to record neuronal activity from populations of neurons in different parts of the olfactory system. To understand how temporally complex odour stimuli are respresented and processed, we analyse neural activity on a single cell and population level, and use machine learning-based data analysis together with computational modelling methods.

The neuronal mechanisms underlying processing of temporally complex odours remain unknown. To investigate this, we perturb and manipulate neuronal activity using opto- and chemogenetic techniques. Employing viral vectors in combination with transgenic mouse lines allows us to target specific cell populations during physiology and behavioural experiments.

In an olfactory-guided navigation task, we investigate which features of complex, naturalistic olfactory cues are informative to animals tracking an odour to its source. In a behavioural arena, animal movement is tracked along with the odour profile that it encounters. In addition, we monitor the animal’s respiration strategy and record neural activity in different olfactory brain regions.