title: Sensory interaction between attractant diacetyl and repellent 2-nonanone in the nematode Caenorhabditis elegans.
abstract: In the nematode Caenorhabditis elegans, the odorant diacetyl is sensed by AWA sensory neurons in the amphid sensory organ and elicits an attractive response, whereas 2-nonanone is sensed by AWB amphid sensory neurons and elicits an avoidance response. In the present study, we report that nematodes exhibit a sensory interaction between the attractant diacetyl and repellent 2-nonanone. In the presence of food, the chemotactic response to 0.01% diacetyl in nematodes preexposed to 0.1% diacetyl was greater than that in nonexposed naive nematodes (P < 0.05). The response to diacetyl was also greater in nematodes preexposed to 3% 2-nonanone in the presence of food than that in naive nematodes (P < 0.01). In the absence of food, the response to diacetyl in nematodes preexposed to diacetyl or 2-nonanone was significantly lower than that in nonexposed control nematodes (P < 0.01). The avoidance response to 10% 2-nonanone in nematodes preexposed to each odorant in the presence or absence of food was lower than that in nonexposed nematodes (P < 0.05). To confirm the validity of our results, the chemotactic responses to diacetyl and 2-nonanone were observed using che-3, odr-4, and odr-10 mutants, which exhibited defective sensitivity to diacetyl or 2-nonanone. From the results of our experiments, we conclude that nematodes exhibit a sensory interaction between diacetyl and 2-nonanone and speculate that this interaction is driven by higher-level neuronal circuits that underlie sensory integration.
authors.affiliation: Laboratory of Behavioral Physiology, Faculty of Engineering, Iwate University, Morioka, Japan. matsuura@iwate‐u.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Matsuura
authors.forename: Junichi
authors.initials: J
authors.lastname: Izumi
authors.forename: Mamoru
authors.initials: M
authors.lastname: Hioki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nagaya
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology; D003931:Diacetyl / Q000494:pharmacology*; D005502:Food; D007659:Ketones / Q000494:pharmacology*; D012677:Sensation / Q000502:physiology; D011984:Sensory Receptor Cells / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D007659:Ketones; D003931:Diacetyl; C026636:2-nonanone