Processing of olfactory information in the brain of Drosophila melanogaster

DUARTE LAUTARO; NICOLAS PIREZ; FERNANDO LOCATELLI

Virtual

Congreso; Congreso SAN 2021; 2021

Sociedad Argentina de Investigaciones en Neurociencias

Odorants aredetected by olfactory receptor neurons (ORNs) that project to the antennal lobe(AL), the first olfactory neuropil in the insect brain, where they makesynaptic contacts with: i) projection neurons (PNs), that constitute the outputof the AL; and ii) local neurons (LNs) that form a dense network of lateralinteractions within the AL. The main goal of this project is to study the roleof the LNs in odor representation using Drosophilamelanogaster. On a firstapproach we downregulated the expression of GABA-A receptors in PNs using RNAiand performed calcium imaging of odor-elicited activity in the AL. We foundthat constitutive reduction of the expression of the Rdl receptor subunitproduced a series of compensations that resulted in the emergence of newinhibitory interactions. This result suggested the existence of a strongdevelopmental plasticity in the AL. As a secondapproach, we aim to acutely and reversibly block the activity of LNs. In thatsense we plan to use shibire, atemperature sensitive mutant, to silence the LNs. Up to now, we tested theeffect that raising the temperature of the flies has on odorant evoked activityat the AL. Preliminary results show that shifting temperature from 22 to 30°C,only faintly alters odor elicited calcium signals. This result opens thepossibility to measure odorant representations with and without thecontribution of the LNs in the same animal.