RT Journal Article
SR Electronic
T1 Serotonin-dependent kinetics of bursts of feeding underlie a graded response to food availability
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 051086
DO 10.1101/051086
A1 Kyung Suk Lee
A1 Shachar Iwanir
A1 Ronen B Kopito
A1 Monika Scholz
A1 David Biron
A1 Erel Levine
YR 2016
UL http://biorxiv.org/content/early/2016/04/29/051086.abstract
AB Animals integrate physiological and environmental signals to modulate their food uptake. Failure to regulate feeding may have devastating results, including obesity and diabetes, underscoring the importance of understanding its underlying mechanisms. The nematode C. elegans, whose food uptake consists of pumping bacteria from the environment into the gut, provides excellent opportunities for discovering principles of conserved regulatory mechanisms. Here we show that worms implement a graded feeding response to the concentration of environmental bacteria by modulating a commitment to bursts of fast pumping. Using long-term, high-resolution, longitudinal recordings of feeding dynamics under defined conditions, we find that the frequency and duration of pumping bursts increase and the duration of long pauses diminishes in environments richer in bacteria. The bioamine serotonin, a known feeding regulator in metazoa, is required for food-dependent induction of bursts as well as for maintaining their high rate of pumping through two distinct mechanisms. Following this phenotype quantitatively we identify the essential serotonergic neurons and the differential roles of distinct families of serotonin receptors. We propose that regulation of bursts is a conserved mechanism of behavior and motor control.