Nitric oxide contributes to high-salt perception in a blood-sucking insect model

CANO, AGUSTINA; PONTES, GINA; SFARA, VALERIA; ANFOSSI, DIEGO; BARROZO, ROMINA B.

Scientific Reports

Nature Publishing Group

Año: 2017 vol. 7

In all organisms, salts produce eitherappetitive or aversive responses depending on the concentration. While low-saltconcentration in food elicits positive responses to ingest, high-salt triggersaversion. Still the mechanisms involved in this dual behavior have just startedto be uncovered in some organisms. In Rhodniusprolixus, using pharmacological and behavioral assays, we demonstrated thatupon high-salt detection in food a nitric oxide (NO) dependent cascade isactivated. This activation involves a soluble guanylate cyclase (sGC) and theproduction of cyclic guanosine monophosphate (cGMP). Thus, appetitive responsesto low-salt diets turn to aversion whenever this cascade is activated.Conversely, insects feed over aversive high-salt solutions when it is blockedby reducing NO levels or by affecting the sGC activity. The activation ofNO/sGC/cGMP cascade commands the avoidance feeding behavior in R. prolixus. Investigations in otherinsect species should examine the possibility that high-salt aversion ismediated by NO/sSG/cGMP signaling.