Abstract
Animals utilize specialized sensory neurons enabling the detection of a wide range of environmental stimuli from the presence of toxic chemicals to that of touch. However, how these neurons discriminate between different kinds of stimuli remains poorly understood. By combining in vivo calcium imaging and molecular genetic manipulation, here we investigate the response patterns and the underlying mechanisms of the C. elegans phasmid neurons PHA/PHB to a variety of sensory stimuli. Our observations demonstrate that PHA/PHB neurons are polymodal sensory neurons which sense harmful chemicals, hyperosmotic solutions and mechanical stimulation. A repulsive concentration of IAA induces calcium elevations in PHA/PHB and both OSM-9 and TAX-4 are essential for IAA-sensing in PHA/PHB. Nevertheless, the PHA/PHB neurons are inhibited by copper and post-synaptically activated by copper removal. Neuropeptide is likely involved in copper removal-induced calcium elevations in PHA/PHB. Furthermore, mechanical stimulation activates PHA/PHB in an OSM-9-dependent manner. Our work demonstrates how PHA/PHB neurons respond to multiple environmental stimuli and lays a foundation for the further understanding of the mechanisms of polymodal signaling, such as nociception, in more complex organisms.
Highlights
The nature of such responses of phasmid neurons to environmental stimuli has yet to be determined on a cellular level and the underlying molecular mechanisms remain unclear
We show that the PHA/PHB neurons respond to a wide range of aversive stimuli including aversive odors, copper, alkaline solution, hyperosmotic solution, and harsh touch
Previous studies have reported that PHA/PHB neurons are required for detergent (SDS)-evoked avoidance behavior[6,7]
Summary
The nature of such responses of phasmid neurons to environmental stimuli has yet to be determined on a cellular level and the underlying molecular mechanisms remain unclear. We show that the PHA/PHB neurons respond to a wide range of aversive stimuli including aversive odors, copper, alkaline solution, hyperosmotic solution, and harsh touch. We further identify critical roles for the TRPV protein OSM-9, the CNG channel protein TAX-4 and the post-synaptic neuropeptide in the sensory transduction of PHA/PHB. Our data suggests that the PHA/PHB neurons are polymodal neurons employing an elaborate combination of intracellular and intercellular signaling pathways to detect and process environmental stimuli
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
