Pond Assay for the Sensory Systems of : A Novel Anesthesia-Free Method Enabling Detection of Responses to Extremely Low Chemical Concentrations.

Chemotaxis in the nematode has basically been examined using conventional assay methods. Although these can be problematic, for example, in their use of anesthesia, the method has never been improved. We propose a pond assay for the sensory systems (PASS) of as a novel population-based method of behavioral analysis. The test solution is injected into a recess(es) formed on agar and the response of to its odor and/or taste is examined. Once individuals fall into recesses (ponds) filled with liquid, they cannot return to a solid medium. In this way, the animals are trapped with certainty without the use of anesthesia. The anesthesia used to keep animals in the attractant area in conventional chemotaxis assays is no longer required, allowing pure evaluation of the attractant or repellent response to specific substances. Furthermore, the assay itself can be greatly streamlined because the preparation can be completed simply by providing a recess(es) and filling the liquid. The present paper reports the detailed method and effectiveness of the novel PASS.