Familiar Food-Induced Feeding Activation in C. Elegans
type: CreativeWork
description: The growing epidemic of obesity and eating disorders demands the study of regulatory mechanisms of food intake. Studying mutants whose food intake is altered under various conditions has greatly advanced our understanding of the mechanism. However, it is still largely unknown by which mechanisms perception of food activates food intake. The simple anatomy, genetic tractability, and well-characterized and quantifiable feeding behavior and evolutionary conservation of feeding regulators make C. elegans an attractive model system for the study. Food intake in C. elegans requires two muscle motions, pharyngeal pumping and isthmus peristalsis, and the frequencies of the two feeding motions dramatically increase in response to food as in other organisms. I attempted to understand the mechanism underlying food-induced feeding activation by studying the mechanism and the physiological context of action of serotonin, an endogenous activator of pharyngeal pumping. Here I show that like food, serotonin increases overall feeding by activating both feeding motions. Serotonin activates the two feeding motions by activating two distinct neural pathways. A 5-HT7 receptor activated the two motions mainly by acting in the two distinct pharyngeal motor neurons that are essential for food-induced feeding activation. Moreover, the results support that the serotonin receptor activated the two distinct neurons mainly by activating two distinct downstream G protein signaling pathways. Despite the separate regulation, isthmus peristalsis was coupled to the preceding pharyngeal pump. The separate regulation with coupling of the two feeding motions may have evolved to support efficient feeding by allowing control of the ratio of the frequencies of the two muscle motions according to density of food and by preventing futile isthmus peristalsis. Then, which aspect of food triggers the serotonin signal that increases food intake? I found that recognition of familiar food selectively triggers the…
abstract: The growing epidemic of obesity and eating disorders demands the study of regulatory mechanisms of food intake. Studying mutants whose food intake is altered under various conditions has greatly advanced our understanding of the mechanism. However, it is still largely unknown by which mechanisms perception of food activates food intake. The simple anatomy, genetic tractability, and well-characterized and quantifiable feeding behavior and evolutionary conservation of feeding regulators make C. elegans an attractive model system for the study. Food intake in C. elegans requires two muscle motions, pharyngeal pumping and isthmus peristalsis, and the frequencies of the two feeding motions dramatically increase in response to food as in other organisms. I attempted to understand the mechanism underlying food-induced feeding activation by studying the mechanism and the physiological context of action of serotonin, an endogenous activator of pharyngeal pumping. Here I show that like food, serotonin increases overall feeding by activating both feeding motions. Serotonin activates the two feeding motions by activating two distinct neural pathways. A 5-HT7 receptor activated the two motions mainly by acting in the two distinct pharyngeal motor neurons that are essential for food-induced feeding activation. Moreover, the results support that the serotonin receptor activated the two distinct neurons mainly by activating two distinct downstream G protein signaling pathways. Despite the separate regulation, isthmus peristalsis was coupled to the preceding pharyngeal pump. The separate regulation with coupling of the two feeding motions may have evolved to support efficient feeding by allowing control of the ratio of the frequencies of the two muscle motions according to density of food and by preventing futile isthmus peristalsis. Then, which aspect of food triggers the serotonin signal that increases food intake? I found that recognition of familiar food selectively triggers the…
author: Song, Bo-mi
language: en
keywords: Caenorhabditis elegans, Feeding Behavior, Serotonin
date published: 2011-08-26T17:35:11Z
date modified: 2026-07-24T05:52:38Z
provider: University of Texas Southwestern Medical Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Texas Southwestern Medical Center

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2152.5/887