title: Modulation of C. elegans touch sensitivity is integrated at multiple levels.
abstract: Sensory systems can adapt to different environmental signals. Here we identify four conditions that modulate anterior touch sensitivity in Caenorhabditis elegans after several hours and demonstrate that such sensory modulation is integrated at multiple levels to produce a single output. Prolonged vibration involving integrin signaling directly sensitizes the touch receptor neurons (TRNs). In contrast, hypoxia, the dauer state, and high salt reduce touch sensitivity by preventing the release of long-range neuroregulators, including two insulin-like proteins. Integration of these latter inputs occurs at upstream neurohormonal cells and at the insulin signaling cascade within the TRNs. These signals and those from integrin signaling converge to modulate touch sensitivity by regulating AKT kinases and DAF-16/FOXO. Thus, activation of either the integrin or insulin pathways can compensate for defects in the other pathway. This modulatory system integrates conflicting signals from different modalities, and adapts touch sensitivity to both mechanical and non-mechanical conditions.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, New York 10027.
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: Chen
authors.forename: Martin
authors.initials: M
authors.lastname: Chalfie
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000502:physiology; D002118:Calcium / Q000502:physiology; D051858:Forkhead Transcription Factors; D000860:Hypoxia / Q000503:physiopathology; D016023:Integrins / Q000502:physiology; D007834:Lasers; D008465:Mechanoreceptors / Q000502:physiology; D009132:Muscles / Q000294:innervation / Q000502:physiology; D059906:Neuroimaging; D051058:Oncogene Protein v-akt / Q000502:physiology; D010812:Physical Stimulation; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology; D013312:Stress, Physiological; D055698:Touch Perception / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology; D014732:Vibration
chemical_list: D029742:Caenorhabditis elegans Proteins; D051858:Forkhead Transcription Factors; D016023:Integrins; D012333:RNA, Messenger; D014157:Transcription Factors; C108831:daf-16 protein, C elegans; D051058:Oncogene Protein v-akt; D002118:Calcium
keywords: insulin signaling; integrin signaling; long-term sensitization; mechanosensation; sensory modulation