A Gustatory Neural Circuit of Caenorhabditis elegans Generates Memory-Dependent Behaviors in Na+ Chemotaxis

作者：Wang Lifang; Sato Hirofumi; Satoh Yohsuke; Tomioka Masahiro; Kunitomo Hirofumi; Iino Yuichi^*

来源：Journal of Neuroscience, 2017, 37(8): 2097-2111.

DOI：10.1523/JNEUROSCI.1774-16.2017

• ASEL
• calcium imaging
• klinokinesis
• neural circuit
• optogenetics
• sodium chemotaxis

Animals show various behaviors in response to environmental chemicals. These behaviors are often plastic depending on previous experiences. Caenorhabditis elegans, which has highly developed chemosensory system with a limited number of sensory neurons, is an ideal model for analyzing the role of each neuron in innate and learned behaviors. Here, we report a new type of memory-dependent behavioral plasticity in Na+ chemotaxis generated by the left member of bilateral gustatory neuron pair ASE (ASEL neuron). When worms were cultivated in the presence of Na+, they showed positive chemotaxis toward Na+, but when cultivated under Na+-free conditions, they showed no preference regarding Na+ concentration. Both channelrhodopsin-2 (ChR2) activation with blue light and up-steps of Na+ concentration activated ASEL only after cultivation with Na+, as judged by increase in intracellular Ca2+. Under cultivation conditions with Na+, photoactivation of ASEL caused activation of its downstream interneurons AIY and AIA, which stimulate forward locomotion, and inhibition of its downstream interneuron AIB, which inhibits the turning/reversal behavior, and overall drove worms toward higher Na+ concentrations. We also found that the Gq signaling pathway and the neurotransmitter glutamate are both involved in the behavioral response generated by ASEL.

• 出版日期2017-2-22