Effect of two helminth parasites on the open-field behaviour of albino mice

Abstract

The effect of Trichinella spiralis and Hymenolepis fraterna on the open-field behaviour of laboratory mice was studied on different days following infection. The hypothesis that helminths with different life-styles will alter specifically the activity of the host so as to increase transmission probability was tested. The results obtained indicated that both parasites produced a qualitatively similar inhibitory effect on mice activity in the open-field. However, significant quantitative differences in their effects were observed. T. spiralis strongly reduced the locomotory and exploratory activity of the mice. The beginning of the effect coincided with the peak of muscle invasion by T. spiralis larvae (day 14 p.i.) and persisted until the end of the experiment (day 30 p.i.). H. fraterna affected much less mice activity. The infection resulted mainly in reduced host locomotion, but the effect was demonstrated only after H. fraterna matured and started oviproduction in the host (14-20 days p.i.). Both parasites studied changed also the pattern of host locomotory activity dynamics during the 15 min open-field tests. It is suggested that altered host activity by the parasites, although qualitatively similar, may involve different mechanisms. The observed alterations in host behaviour are discussed in terms of the manipulation hypothesis. It is concluded that infection did not alter specifically mice open-field behaviour and the observed decline in host activity is the side effect of pathology or other constrains set by the parasites, rather than specific evolutionary based alteration of behaviour.

Linking Behavior, Co-infection Patterns, and Viral Infection Risk With the Whole Gastrointestinal Helminth Community Structure in Mastomys natalensis

“…This may then result in a lower mobility during the hole-board test, since the host has to share its resources with its intestinal parasites, especially when these parasites occupy different parts inside the gastrointestinal tract (95,96). Such an effect has been found in lab mice, for instance, where individuals who were infected with Trichinella spiralis or Hymenolepis fraternal became less active inside an open-field test (115). In this study, P. muricola infection in particular may have a strong impact on the resource availability of our study species.…”