PheroSys: Olfactory Coding in the Insect Pheromone Pathway: Models and Experiments

Scientific Abstract

The aim of our project is to investigate olfactory information processing in the first stages of the olfactory pathway. We will conduct experiments and modelling studies in the pheromone subsystem of the moth Spodoptera littoralis (the cotton leafworm).

• investigate the transduction mechanism in the olfactory receptor neurons (ORNs) with tip-recording in vivo and patch clamp recordings in vitro,
• determine the prevalence and distribution of different types of ORNs and their projections to the macro-glomerular complex (MGC), and
• record the activity of MGC neurons in response to a rich set of odour stimuli while monitoring the local field potential.

• build detailed, biophysical models of the ORNs, combining experimental data (1b) with existing submodels of perireception, reception, and post-reception processes,
• reconstruct the compound signal sent by the ORNs to the MGC based on modelling (2a) and experimental data (1b),
• develop conductance-based models of single glomeruli using modern data fitting technology (synchronization based parameter estimation employing genetic algorithms and multiple shooting) to adjust the models to the data (1b, 1c),
• reduce the detailed models to network models of IF neurons and analyse their response and coding properties mathematically, and
• build similar detailed and reduced models of the full MGC to analyse the following open questions (in both the oneglomerulus and full MGC models):
• Is the connectivity of olfactory systems well described by a random network or does it follow a different construction principle?
• How does the pheromone system achieve its outstanding sensitivity and specificity and maintain them in the presence of noise?
• What is the origin and role of oscillations in the MGC or olfactory systems in general? What is the function of phase locking and synchronization and how does inhibition contribute to it?