Should I eat or should I not? Bitter perception in a blood-feeding insect

PONTES, GINA; ORTEGA INSAURRALDE, ISABEL; DE BRITO SANCHEZ, GABRIELA; MINOLI, SEBASTIAN; BARROZO, ROMINA

Huerta Grande, Cordoba

Congreso; XXVII CONGRESO ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN EN NEUROCIENCIAS; 2013

SOCIEDAD ARGENTINA DE INVESTIGACIÓN EN NEUROCIENCIAS

Food quality assessment is associated to an animal decision about feeding or not. Once triatomine insects reach a potentially suitable host, they walk over their skin in search of a good quality substrate (skin recognition phase) and then they pierce the skin until a venule or arteriole is reached. Subsequently they suck a small quantity of blood initiating the sampling phase of food. We show here that the fine discrimination of gustatory preferences in triatomines occurs during both, the skin recognition phase and the sampling phase, independently. Triatomines have 4 chaetic taste sensilla localized in the tip antenna that serve to determine externally the gustatory nature of the substrate. These taste sensilla showed electrophysiological sensitivity to caffeine (CAF) and quinine (QUI). In feeding experiments we found that by adding CAF or QUI to the membrane of an artificial feeder offering an appetitive solution prevents larvae from feeding. Additionally, the addition of CAF or QUI to the appetitive solution but not to the piercing membrane also caused an inhibition of the feeding behaviour of triatomines. This modulation seems to occur by means of internal taste receptors placed in their alimentary canal (the epipharingeal organ). Finally, by applying a cognitive approach, we found that both, skin recognition and sampling phases, are modulated by experience. Results presented here highlight the relevance of taste perception in the modulation of the feeding behaviour of insects