posted on 2016-11-09, 09:10authored byL. Grécias, F. O. Hébert, C. S. Berger, Iain Barber, N. Aubin-Horth
Sticklebacks infected by the parasitic flatworm Schistocephalus solidus show dramatic changes in phenotype, including a loss of species-typical behavioural responses to predators. The timing of host behaviour change coincides with the development of infectivity of the parasite to the final host (a piscivorous bird), making it an ideal model for studying the mechanisms of infection-induced behavioural modification. However, whether the loss of host anti-predator behaviour results from direct manipulation by the parasite, or is a by-product (e.g. host immune response) or side-effect of infection (e.g. energetic loss), remains controversial. To understand the physiological mechanisms that generate these behavioural changes, we quantified the behavioural profiles of experimentally infected fish and attempted to replicate these in non-parasitized fish by exposing them to treatments including immunity activation and fasting, or by pharmacologically inhibiting the stress axis. All fish were screened for the following behaviours: activity, water depth preference, sociability, phototaxis, anti-predator response and latency to feed. We were able to change individual behaviours with certain treatments. Our results suggest that the impact of S. solidus on the stickleback might be of a multifactorial nature. The behaviour changes observed in infected fish may be due to the combined effects of modifying the serotonergic axis, the lack of energy, and the activation of the immune system.
Funding
This study was funded through a Fonds de recherche du Québec – Nature et
technologies (FRQNT) Programme de Recherche en Équipe grant to NAH, a Conseil de
recherches en sciences naturelles et en génie du Canada (CRSNG) grant through the
Discovery grant program to NAH, funding from the University of Leicester to IB, a Vanier
Canada Graduate Scholarship from CRSNG to FOH, a Ressources Aquatiques Québec
(RAQ) travel fellowship to LG, and a Explo’ RA Sup de la région Rhône-Alpes fellowship
to CSB.
History
Citation
Journal of Experimental Biology, 2016
Author affiliation
/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/MBSP Non-Medical Departments/Neuroscience, Psychology and Behaviour