Sensory and Motor Systems
Author: Lautaro Duarte | Email: duartelautaro5@gmail.com
Lautaro Duarte1°, Martín Klappenbach1°2°,Nicolás Pírez1°2°, Fernando Locatelli1°2°
1° Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET
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), which in turn send olfactory information to other brain areas; and ii) local interneurons (LNs) that form a dense network of lateral inhibitory and excitatory interactions within the AL. Functional and computational studies indicate that this local network transforms sensory information, presumably to enhance perception of meaningful odor. Here, we investigate the role of local GABAergic neurons in both learning-dependent plasticity in the AL and the ability of flies to perceive the presence of learned odors in mixtures. For that aim, we performed aversive olfactory conditioning using a single odorant as the conditioned stimulus. We then tested olfactory avoidance in a T-maze by exposing the flies to the conditioned odor either pure or in different proportions mixed with a novel odor. We determined the threshold proportions that flies need to detect the learned odors immersed in the mixture. These proportions are odor and mixture specific. Next, we are studying whether blocking the activity of the LNs in the AL abolishes the ability of flies to detect learned odors embedded in mixtures.
Finally, we asked whether olfactory aversive conditioning affects the representation of odor mixtures in the antennal lobe. We recorded odor evoked responses of PNs using