title: Identification of motor neurons and a mechanosensitive sensory neuron in the defecation circuitry of Drosophila larvae.
abstract: Defecation allows the body to eliminate waste, an essential step in food processing for animal survival. In contrast to the extensive studies of feeding, its obligate counterpart, defecation, has received much less attention until recently. In this study, we report our characterizations of the defecation behavior of Drosophila larvae and its neural basis. Drosophila larvae display defecation cycles of stereotypic frequency, involving sequential contraction of hindgut and anal sphincter. The defecation behavior requires two groups of motor neurons that innervate hindgut and anal sphincter, respectively, and can excite gut muscles directly. These two groups of motor neurons fire sequentially with the same periodicity as the defecation behavior, as revealed by in vivo Ca(2+) imaging. Moreover, we identified a single mechanosensitive sensory neuron that innervates the anal slit and senses the opening of the intestine terminus. This anus sensory neuron relies on the TRP channel NOMPC but not on INACTIVE, NANCHUNG, or PIEZO for mechanotransduction.
authors.affiliation: Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, China.
authors.forename: Bingxue
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States.
authors.forename: Lily Yeh
authors.initials: LY
authors.lastname: Jan
authors.affiliation: Department of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States.
authors.forename: Yuh Nung
authors.initials: YN
authors.lastname: Jan
mesh_terms: D000200:Action Potentials / Q000528:radiation effects; D001003:Anal Canal / Q000502:physiology / Q000528:radiation effects; D000818:Animals; D001369:Axons / Q000378:metabolism; D003672:Defecation / Q000502:physiology* / Q000528:radiation effects; D004064:Digestive System / Q000294:innervation / Q000528:radiation effects; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000502:physiology* / Q000528:radiation effects; D025461:Feedback, Physiological / Q000528:radiation effects; D007091:Image Processing, Computer-Assisted; D007814:Larva / Q000502:physiology / Q000528:radiation effects; D008027:Light; D040542:Mechanotransduction, Cellular / Q000528:radiation effects; D008959:Models, Neurological; D009046:Motor Neurons / Q000502:physiology* / Q000528:radiation effects; D009119:Muscle Contraction / Q000528:radiation effects; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011984:Sensory Receptor Cells / Q000502:physiology* / Q000528:radiation effects
chemical_list: D029721:Drosophila Proteins
keywords: D. melanogaster; defecation; mechanotransduction; neural circuitry; neuroscience