title: The correlation between tick (Ixodes persulcatus Sch.) questing behaviour and synganglion neuronal responses to odours.
abstract: We examined the behavioural and electrophysiological responses of taiga ticks (Ixodes persulcatus) to several olfactory stimuli: Osmopherone® (5-a-androst-16-en-3-ol), Osmopherine® (butanoic and 3-methylbutanoic acids), DEET® (N,N-diethyl-meta-toluamide), ethanol (96%), and water (control stimulus). To study individual tick behavioural reactions to these stimuli, we used a Y-shaped glass maze (n=50). To study the electrophysiological reactions of the ticks' synganglia to these olfactory stimuli, we recorded the shifts of total potential (TP) of pre-oesophageal neurons in response to odour stimulation of Haller's organ (n=25). We found that Osmopherine® attracted ticks and frequently evoked negative shifts of TP, whereas the response to Osmopherone® did not differ from the reaction to water. DEET® and ethanol acted as tick repellents and generally evoked positive shifts of TP. We also tested each tick for its questing height (QH) on a glass rod that was at an incline of 75°, and we tested for the presence of pathogens i.e., DNA of Borrelia burgdorferi sp. s.l. and RNA of tick-borne encephalitis virus (TBEV). The degree of response to Osmopherine® positively correlated with the QH. The ticks with the highest values of QH showed a greater prevalence of the tick-borne pathogen Borrelia sp. s.l. compared with the ticks that did not reach the maximum QH. The present results show a correlation between the electrophysiological reaction of the synganglia of ticks and their behavioural responses to different odours.
authors.affiliation: Institute of Cytology and Genetics, SB RAN, Novosibirsk, Academic Lavrent'ev Avenue, 10, Russia. yuter2006@yandex.ru
authors.forename: A V
authors.initials: AV
authors.lastname: Romashchenko
authors.forename: A S
authors.initials: AS
authors.lastname: Ratushnyak
authors.forename: T A
authors.initials: TA
authors.lastname: Zapara
authors.forename: S E
authors.initials: SE
authors.lastname: Tkachev
authors.forename: M P
authors.initials: MP
authors.lastname: Moshkin
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001898:Borrelia / Q000502:physiology; D018884:Ixodes / Q000382:microbiology / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D009812:Odorants / Q000032:analysis*