Behavioral changes in Rattus norvegicus coinfected by Toxocara canis and Toxoplasma gondii

Abstract

SUMMARYUsing an elevated plus maze apparatus and an activity cage, behavioral changes in Rattus norvegicus concomitantly infected by Toxocara canis and Toxoplasma gondii were studied, during a period of 120 days. Rats infected by Toxocara canis or Toxoplasma gondii showed significant behavioral changes; however, in the group coinfected by both parasites a behavioral pattern similar to that found in the group not infected was observed thirty days after infection, suggesting the occurrence of modulation in the behavioral response.

BEHAVIORAL AND MEMORY CHANGES IN Mus musculus COINFECTED BY Toxocara canis AND Toxoplasma gondii

“…However, the animals infected with T. gondii showed a significant difference in this test. These results support the hypothesis that animals chronically infected with T. gondii have impaired learning and memory 31,43 and reinforces the hypothesis of QUEIROZ et al 33 concerning the occurrence of modulation in the behavioral response when rodents were co-infected by both parasites.…”

“…One hypothesis regarding the lack of significance in the behavioral data of the group infected with T. canis is the quantity of eggs used for the mice infection. However, QUEIROZ et al 33 had already found similar results in Rattus norvegicus concomitantly infected by Toxocara canis and Toxoplasma gondii , suggesting occurrence of a modulation in behavioral changes when rats were concomitantly infected. On the other hand, COX & HOLLAND 12,13 found that mice with large amount of T. canis larvae in the brain (inoculums of 3,000, embryonated) present increased behavioral alterations than mice infected by smaller quantities of larvae.…”

“…Some studies show evidence of behavioral changes in rodents in experimental protocols with single infections; however, in natural conditions, the occurrence of co-infection or multiple parasite infections of the same host should be common 4,8,26,33,35,40,42 .…”

“…QUEIROZ et al 33 investigated the behavior of Rattus norvegicus infected by Toxocara canis and/or Toxoplasma gondii , and concluded that both parasites influenced rodent behavior. However, when the rats were concomitantly infected, a behavior modulation was observed, resulting in slight absence of behavioral alterations.…”

Conflicts over host manipulation between different parasites and pathogens: Investigating the ecological and medical consequences

“…Doubly infected rats slightly resemble T. canis rats in their behaviour [58]. However, singly infected animals behave similarly to each other [57,58], not illustrating any clear conflict between the parasites. These studies indicate that two parasites with conflicting interests could both have an effect on host behaviour leading to host behaviour that unites traits of hosts that are singly infected by either parasite.…”