Cognition, Behavior, and Memory
Author: Marcos Rafael Sorrentino | Email: marcosrafa.sorrentino@gmail.com
Marcos Rafael Sorrentino1°, Nicolás Pírez1°2°, Fernando Locatelli1°2°
1° Departamento de Fisiología, Biología Molecular y Celular; Facultad de Ciencias Exactas y Naturales; Universidad de Buenos Aires, Argentina.
2° Instituto de Fisiología, Biología Molecular y Neurociencias; UBA-CONICET, Argentina.
Here we investigate the contribution of the temporal order of odorants, as well as the role of sensory adaptation in the identification of meaningful olfactory stimuli. Recent experiments from our lab demonstrated that the ability of honeybees to detect target odorants embedded in complex mixtures is improved when bees are exposed to the masking odorants before conditioning with a mixture that contains both odorants. However, it remained unclear whether this capacity was due to the animals being adapted to the masking odor or to the animals learning that the masking odor predicted no reinforcement. To disambiguate it, we performed olfactory conditioning experiments in which unrewarded exposure to the masking odors was made before or after rewarded trials using as conditioned odor a mixture of both odors. We observed that specific learning towards the target odor was improved only when prolonged exposure to the masking odor precedes rewarded trials with the mixture, while it did not when unrewarded exposures were made immediately after the rewarded trial. These observations led to subsequent experiments aiming to demonstrate the animal’s ability to distinguish among different temporal orders of the odorants. Two experimental protocols were proposed using quantitative analysis tools to explore this new paradigm. Our results support the idea that olfactory working memory and sensory adaptation serves as fundamental mechanisms to sharpen olfactory discrimination.