Configural or elemental representation of complex odor stimuli in the olfactory system of Drosophila melanogaster

DUARTE, L. A.; LOCATELLI, F. F.; PÍREZ, N.

Villa Carlos Paz

Congreso; XXXIV Reunión Anual SAN 2019; 2019

Sociedad Argentina de Investigación en Neurociencias

The olfactory system is an excellent model to study how sensory stimuli are detected and processed in the brain. Odor molecules bind to receptor proteins expressed in the olfactory receptor neurons (ORNs), which project to the antennal lobe (AL). Here, all ORNs that express the same receptor converge into glomeruli and make contact with projection neurons (PNs), which constitute the output of the AL, and with local neurons (LNs) that form a network of lateral interactions. Due to the spatial organization of the input to the AL, each odor is encoded as a combination of coactivated glomeruli. The response elicited by a mixture of odors differs from the summation of the activity elicited by the elements that constitute the mixture. It is thought that this non-elemental representation accounts for the perception of the mixture as a novel stimulus, different from the components. Here we study the representation of pure odors and its mixture in the AL of Drosophila melanogaster flies. We perform optical calcium imaging at the level of the AL by expressing GCaMP6 in the PNs. We measure the representation of pure odors and mixtures. The differences among the patterns of activity elicited by the mixture and those expected on the basis of the activity elicited by pure components reveals the action of the local network which is based mainly on GABAergic inhibitions. Future studies are directed to measure the representation of the mixture while interfering with the action of the LNs.