Detecting minority components in a binary mixture: the role of olfactory sensory adaptation

PÍREZ, N.; GASCUE, F.; LOCATELLI, F

Mar del Plata

Congreso; Reunión Anual Sociedad Argentina de Investigación en Neurociencias; 2017

SAN

The olfactory system is an excellent model system to study how contextual information is detected and processed by the nervous system. The coding of olfactory information undergoes multiple changes due to prolonged or repeated exposures to odorants. Sensory adaptation is defined as a phenomenon by which the sensitivity towards a stimulus is rapidly decreased after a prolonged exposure to it; it is followed by a complete recovery after the disappearance of the stimulus. Here, we use Apis mellifera to study the effect that the olfactory sensory adaptation has on the capability of animals to detect minor components embedded in binary mixtures. By means of behavioral experiments, we were able to show that olfactory sensory adaptation reduces the learning level of pre-exposed stimuli, while enhancing the learning of stimuli that would be normally overshadowed by the major component of the mixture. Additionally, by performing calcium imaging experiments to measure odor induced signals in the olfactory system, we were able to show that the glomerular activation patterns elicited by a binary mixture, changes after pre-exposure of the animal to one of the components, resulting in a representation that drastically favors the underrepresented (or minor) component of the mixture. These results suggest that olfactory sensory adaptation is critical to allow detection of minor components present in complex in mixtures, and that it increases the sensibility of the animal to certain stimuli.