Neural modulation of feeding behaviors in C. elegans

BLANCO, M.G.; ZABALA, M.A.; ALKEMA, M.J.; DE ROSA M.J.; RAYES, D.

Virtual

Congreso; XXXVI Anual meeting SAN; 2021

Feeding is a complex behavior controlled by environmental and internal physiological factors. The nervoussystem modulates motor activity depending on the availability of food and the nutritional state. When animalsfind food after a fasting period, they stay in a small area to exploit the new source of nutrients. Biogenic amines,serotonin (5-HT) and norepinephrine (NE) are involved in the modulation of food-related behaviors inmammals. However, the molecular mechanisms underlying this regulation are not entirely clear. Given itssimplicity and highly conserved neurological pathways, C. elegans is a powerful organism that can be used toprovide insights into the neural circuits modulating feeding behaviors.When starved worms find food, 5-HT is released to decrease locomotion and promote food intake. We foundthat mutants lacking tyramine (TA), NE analog in invertebrates, are hypersensitive to the slowing-downresponse upon food encounter, resembling starved worms. This suggests that 5-HT and TA exert antagonisticeffects. Moreover, the activity of tyraminergic neurons decreases in absence of food. In addition, serotonergicactivity is enhanced in TA-deficient mutants. These results allow us to hypothesize that the inhibition of thetyraminergic activity during fasting favors the exacerbation of 5-HT-dependent effects on refeeding. Given theconservation in neuronal components, it is likely that our studies are significant to understand feedingbehaviors in other animals.