256 | Odor mixture detection in Drosophila melanogaster

Sensory and Motor Systems

Author: Lautaro Alejandro Duarte | Email: Duartelautaro5@gmail.com

Lautaro Alejandro Duarte , Martin Klappenbach 1°2°, Nicolás Pírez 1°2°, Fernando Locatelli 1°2°

1° Instituto de Fisiología, Biología Molecular y Neurociencias; UBA-CONICET, Argentina.
2° Departamento de Fisiología, Biología Molecular y Celular; Facultad de Ciencias Exactas y Naturales; Universidad de Buenos Aires, Argentina.

Odorants are detected by olfactory receptor neurons (ORNs) that project to the antennal lobe
(AL), the first olfactory neuropil in the insect brain. In the AL, ORNs make synaptic contacts
with: i) projection neurons (PNs) that send olfactory information to other brain areas; and ii)
local interneurons (LNs) that form a dense network of lateral interactions within the AL.
Functional studies indicate that this network reshapes sensory information, presumably to
enhance perception of meaningful odors. In this project we investigate the role of GABAergic
interactions in relation to learning dependent neural plasticity in the AL. Our previous work
showed that the representation of a mixture in the AL changes after aversive conditioning,
making the learned component more salient. Now we are performing aversive olfactory
conditioning using a T-maze. We train flies to associate an electric shock with an odor that they
have to avoid during the test session. To study how animals perceive mixtures, we evaluate
the ability of the animals to detect the presence of the learned odor immersed in a binary
mixture. To do that, we test the flies with two stimuli: a novel odor versus a mixture that
contains the associated odor. Future experiments are directed to evaluate whether blocking
the LNs activity impairs learning dependent changes and the ability to detect learned