Serotonin regulates C. elegans fat and feeding through independent molecular mechanisms.
We investigated serotonin signaling in C. elegans as a paradigm for neural regulation of energy balance and found that serotonergic regulation of fat is molecularly distinct from feeding regulation. Serotonergic feeding regulation is mediated by receptors whose functions are not required for fat regulation. Serotonergic fat regulation is dependent on a neurally expressed channel and a G protein-coupled receptor that initiate signaling cascades that ultimately promote lipid breakdown at peripheral sites of fat storage. In turn, intermediates of lipid metabolism generated in the periphery modulate feeding behavior. These findings suggest that, as in mammals, C. elegans feeding behavior is regulated by extrinsic and intrinsic cues. Moreover, obesity and thinness are not solely determined by feeding behavior. Rather, feeding behavior and fat metabolism are coordinated but independent responses of the nervous system to the perception of nutrient availability.
Department of Physiology and UCSF Diabetes Center, University of California, San Francisco, San Francisco, CA 94158-2517, USA.
Supriya
S
Srinivasan
Leila
L
Sadegh
Ida C
IC
Elle
Anne G L
AG
Christensen
Nils J
NJ
Faergeman
Kaveh
K
Ashrafi
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism*; D004734:Energy Metabolism; D005247:Feeding Behavior; D050356:Lipid Metabolism; D012701:Serotonin / Q000502:physiology*
D012701:Serotonin