Nitric oxide pathway to modulate feeding behaviour in a blood-sucking insect.

CANO, A; PONTES, G; SFARA, V; MOUGABURE CUETO, G; BARROZO, RB

Cordoba

Congreso; XXVIII Congreso Annual de la Sociedad Argentina de Investigacion en Neurociencias; 2013

Gustatory sense provides animals with reliable information about the quality of a food source, contributing to discriminate nutritious from harmful food. Taste receptors located in the oral cavity are responsible for a primary evaluation of food. Nitric oxide (NO) is a neuromodulator that participates in many physiological processes in living organisms, including chemosensory perception. In insects, NO modifies sensory inputs and behavioural responses associated to chemical stimuli, both olfactory and gustatory. In this work, we studied the role of NO in the food assessment capacity by Rhodnius prolixus. Insects were treated (or not) for 1 min with a NO donor (SNAC) at different concentrations prior to a feeding test with an appetitive solution (AS) and the weight gained after 10 min was registered. Food intake significantly decreased in insects treated SNAC, suggesting the activation of an antiappetitive pathway. NO triggers the production of GMPc due to the activation of a soluble guanylyl cyclase (sGC), therefore we treated insects with analogues or inhibitors of this pathway. We observed that bugs treated with a GMPc analogue also provoke an inhibitory effect. Additionally, the inhibitory feeding of NO was prevented by adding a sGC inhibitor to the pre-treatment. Our results suggest that NO could act through a sGC that bears the production of GMPc and ultimately the NO might exert a peripheral gustatory modulation affecting insect?s final decision about feeding.     This work was financially supported by the ANPCyT and the CONICET Argentina.