Parasitology

Original Articles

Specificity of the Toxoplasma gondii-altered behaviour to definitive versus non-definitive host predation risk

P. H. L. LAMBERTONa1 p1, C. A. DONNELLYa2 p1 and J. P. WEBSTERa1 p1 c1

a1 Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3SY, UK

a2 MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology Faculty of Medicine, Imperial College, Norfolk Place, London, W2 1PG, UK

SUMMARY

The hypothesis that the parasite Toxoplasma gondii manipulates the behaviour of its intermediate rat host in order to increase its chance of being predated specifically by its feline definitive host, rather than a non-definitive host predator species, was tested. The impact of a range of therapeutic drugs, previously demonstrated to be effective in preventing the development of T. gondii-associated behavioural and cognitive alterations in rats, on definitive-host predator specificity was also tested. Using a Y-shaped maze design, we demonstrated that T. gondii-associated behavioural changes, apparently aimed to increase predation rate, do appear to be specific to that of the feline definitive host – there were significant and consistent differences between the (untreated) infected and uninfected rats groups where T. gondii-infected rats tended to choose the definitive host feline-predator-associated maze arm and nest-box significantly more often than a maze arm or nest-box treated with non-definitive host predator (mink) odour. Drug treatment of infected rats prevented any such host-specificity from being displayed. We discuss our results in terms of their potential implications both for T. gondii epidemiology and the evolution of parasite-altered behaviour.

(Received April 02 2008)

(Revised April 15 2008)

(Accepted May 16 2008)

(Online publication July 14 2008)

Correspondence:

c1 Corresponding author and address for request for materials: Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College, Norfolk Place, London W2 1PG, UK. E-mail: joanne.webster@imperial.ac.uk

p1 Current address: Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College, Norfolk Place, London W2 1PG, UK.

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