Chronic Toxoplasma infection modifies the structure and the risk of host behavior.

The intracellular parasite Toxoplasma has an indirect life cycle, in which felids are the definitive host. It has been suggested that this parasite developed mechanisms for enhancing its transmission rate to felids by inducing behavioral modifications in the intermediate rodent host. For example, To...

Full description

Saved in:
Bibliographic Details
Main Authors: Cristina Afonso, Vitor B Paixão, Rui M Costa
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2012-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0032489&type=printable
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850224569329123328
author Cristina Afonso
Vitor B Paixão
Rui M Costa
author_facet Cristina Afonso
Vitor B Paixão
Rui M Costa
author_sort Cristina Afonso
collection DOAJ
description The intracellular parasite Toxoplasma has an indirect life cycle, in which felids are the definitive host. It has been suggested that this parasite developed mechanisms for enhancing its transmission rate to felids by inducing behavioral modifications in the intermediate rodent host. For example, Toxoplasma-infected rodents display a reduction in the innate fear of predator odor. However, animals with Toxoplasma infection acquired in the wild are more often caught in traps, suggesting that there are manipulations of intermediate host behavior beyond those that increase predation by felids. We investigated the behavioral modifications of Toxoplasma-infected mice in environments with exposed versus non-exposed areas, and found that chronically infected mice with brain cysts display a plethora of behavioral alterations. Using principal component analysis, we discovered that most of the behavioral differences observed in cyst-containing animals reflected changes in the microstructure of exploratory behavior and risk/unconditioned fear. We next examined whether these behavioral changes were related to the presence and distribution of parasitic cysts in the brain of chronically infected mice. We found no strong cyst tropism for any particular brain area but found that the distribution of Toxoplasma cysts in the brain of infected animals was not random, and that particular combinations of cyst localizations changed risk/unconditioned fear in the host. These results suggest that brain cysts in animals chronically infected with Toxoplasma alter the fine structure of exploratory behavior and risk/unconditioned fear, which may result in greater capture probability of infected rodents. These data also raise the possibility that selective pressures acted on Toxoplasma to broaden its transmission between intermediate predator hosts, in addition to felid definitive hosts.
format Article
id doaj-art-e0aa22d5f84f4f47a839701c89b0c15d
institution OA Journals
issn 1932-6203
language English
publishDate 2012-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-e0aa22d5f84f4f47a839701c89b0c15d2025-08-20T02:05:35ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0173e3248910.1371/journal.pone.0032489Chronic Toxoplasma infection modifies the structure and the risk of host behavior.Cristina AfonsoVitor B PaixãoRui M CostaThe intracellular parasite Toxoplasma has an indirect life cycle, in which felids are the definitive host. It has been suggested that this parasite developed mechanisms for enhancing its transmission rate to felids by inducing behavioral modifications in the intermediate rodent host. For example, Toxoplasma-infected rodents display a reduction in the innate fear of predator odor. However, animals with Toxoplasma infection acquired in the wild are more often caught in traps, suggesting that there are manipulations of intermediate host behavior beyond those that increase predation by felids. We investigated the behavioral modifications of Toxoplasma-infected mice in environments with exposed versus non-exposed areas, and found that chronically infected mice with brain cysts display a plethora of behavioral alterations. Using principal component analysis, we discovered that most of the behavioral differences observed in cyst-containing animals reflected changes in the microstructure of exploratory behavior and risk/unconditioned fear. We next examined whether these behavioral changes were related to the presence and distribution of parasitic cysts in the brain of chronically infected mice. We found no strong cyst tropism for any particular brain area but found that the distribution of Toxoplasma cysts in the brain of infected animals was not random, and that particular combinations of cyst localizations changed risk/unconditioned fear in the host. These results suggest that brain cysts in animals chronically infected with Toxoplasma alter the fine structure of exploratory behavior and risk/unconditioned fear, which may result in greater capture probability of infected rodents. These data also raise the possibility that selective pressures acted on Toxoplasma to broaden its transmission between intermediate predator hosts, in addition to felid definitive hosts.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0032489&type=printable
spellingShingle Cristina Afonso
Vitor B Paixão
Rui M Costa
Chronic Toxoplasma infection modifies the structure and the risk of host behavior.
PLoS ONE
title Chronic Toxoplasma infection modifies the structure and the risk of host behavior.
title_full Chronic Toxoplasma infection modifies the structure and the risk of host behavior.
title_fullStr Chronic Toxoplasma infection modifies the structure and the risk of host behavior.
title_full_unstemmed Chronic Toxoplasma infection modifies the structure and the risk of host behavior.
title_short Chronic Toxoplasma infection modifies the structure and the risk of host behavior.
title_sort chronic toxoplasma infection modifies the structure and the risk of host behavior
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0032489&type=printable
work_keys_str_mv AT cristinaafonso chronictoxoplasmainfectionmodifiesthestructureandtheriskofhostbehavior
AT vitorbpaixao chronictoxoplasmainfectionmodifiesthestructureandtheriskofhostbehavior
AT ruimcosta chronictoxoplasmainfectionmodifiesthestructureandtheriskofhostbehavior