title: A Circuit for Gradient Climbing in C. elegans Chemotaxis.
abstract: Animals have a remarkable ability to track dynamic sensory information. For example, the nematode Caenorhabditis elegans can locate a diacetyl odor source across a 100,000-fold concentration range. Here, we relate neuronal properties, circuit implementation, and behavioral strategies underlying this robust navigation. Diacetyl responses in AWA olfactory neurons are concentration and history dependent; AWA integrates over time at low odor concentrations, but as concentrations rise, it desensitizes rapidly through a process requiring cilia transport. After desensitization, AWA retains sensitivity to small odor increases. The downstream AIA interneuron amplifies weak odor inputs and desensitizes further, resulting in a stereotyped response to odor increases over three orders of magnitude. The AWA-AIA circuit drives asymmetric behavioral responses to odor increases that facilitate gradient climbing. The adaptation-based circuit motif embodied by AWA and AIA shares computational properties with bacterial chemotaxis and the vertebrate retina, each providing a solution for maintaining sensitivity across a dynamic range.
authors.affiliation: Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA.
authors.forename: Johannes
authors.initials: J
authors.lastname: Larsch
authors.affiliation: Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Flavell
authors.affiliation: Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gordus
authors.affiliation: Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA.
authors.forename: Dirk R
authors.initials: DR
authors.lastname: Albrecht
authors.affiliation: Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA. Electronic address: cori@rockefeller.edu.
authors.forename: Cornelia I
authors.initials: CI
authors.lastname: Bargmann
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology*; D007395:Interneurons / Q000502:physiology; D009812:Odorants; D018034:Olfactory Receptor Neurons / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000502:physiology; D015398:Signal Transduction
chemical_list: D029742:Caenorhabditis elegans Proteins