scholarly journals Toxoplasma gondii: Model Manipulating by the Host Behaviour

2021 ◽  
Vol 30 (1) ◽  
pp. 18-27
Author(s):  
Musafer AlArdi
Keyword(s):  
Toxoplasma Gondii ◽  
Host Behaviour

Insights into the molecular basis of host behaviour manipulation by Toxoplasma gondii infection

2017 ◽  
Vol 1 (6) ◽  
pp. 563-572 ◽  
Author(s):  
Pierre-Mehdi Hammoudi ◽  
Dominique Soldati-Favre
Keyword(s):  
Toxoplasma Gondii ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Brain Regions ◽  
Intermediate Hosts ◽  
Toxoplasma Gondii Infection ◽  
Host Parasite ◽  
Host Behaviour ◽  
The Brain ◽  
Brain Homeostasis

Typically illustrating the ‘manipulation hypothesis’, Toxoplasma gondii is widely known to trigger sustainable behavioural changes during chronic infection of intermediate hosts to enhance transmission to its feline definitive hosts, ensuring survival and dissemination. During the chronic stage of infection in rodents, a variety of neurological dysfunctions have been unravelled and correlated with the loss of cat fear, among other phenotypic impacts. However, the underlying neurological alteration(s) driving these behavioural modifications is only partially understood, which makes it difficult to draw more than a correlation between T. gondii infection and changes in brain homeostasis. Moreover, it is barely known which among the brain regions governing fear and stress responses are preferentially affected during T. gondii infection. Studies aiming at an in-depth dissection of underlying molecular mechanisms occurring at the host and parasite levels will be discussed in this review. Addressing this reminiscent topic in the light of recent technical progress and new discoveries regarding fear response, olfaction and neuromodulator mechanisms could contribute to a better understanding of this complex host–parasite interaction.

scholarly journals When should a trophically and vertically transmitted parasite manipulate its intermediate host? The case of Toxoplasma gondii

2013 ◽  
Vol 280 (1765) ◽  
pp. 20131143 ◽  
Author(s):  
Maud Lélu ◽  
Michel Langlais ◽  
Marie-Lazarine Poulle ◽  
Emmanuelle Gilot-Fromont ◽  
Sylvain Gandon
Keyword(s):  
Toxoplasma Gondii ◽  
Vertical Transmission ◽  
Death Rate ◽  
Predation Rate ◽  
Life Cycles ◽  
Intermediate Hosts ◽  
Complex Life Cycles ◽  
Virulent Strains ◽  
Host Behaviour ◽  
Different Levels

Parasites with complex life cycles are expected to manipulate the behaviour of their intermediate hosts (IHs), which increase their predation rate and facilitate the transmission to definitive hosts (DHs). This ability, however, is a double-edged sword when the parasite can also be transmitted vertically in the IH. In this situation, as the manipulation of the IH behaviour increases the IH death rate, it conflicts with vertical transmission, which requires healthy and reproducing IHs. The protozoan Toxoplasma gondii , a widespread pathogen, combines both trophic and vertical transmission strategies. Is parasite manipulation of host behaviour still adaptive in this situation? We model the evolution of the IH manipulation by T. gondii to study the conflict between these two routes of transmission under different epidemiological situations. Model outputs show that manipulation is particularly advantageous for virulent strains and in epidemic situations, and that different levels of manipulation may evolve depending on the sex of the IH and the transmission routes considered. These results may help to understand the variability of strain characteristics encountered for T. gondii and may extend to other trophically transmitted parasites.

scholarly journals Toxoplasma gondii-altered host behaviour: clues as to mechanism of action

2010 ◽  
Vol 57 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Joanne P. Webster ◽  
Glenn A. McConkey
Keyword(s):  
Toxoplasma Gondii ◽  
Mechanism Of Action ◽  
Host Behaviour

Toxoplasma gondii-altered host behaviour: Clues as to mechanisms of action and implications for its role in some cases of human schizophrenia

2011 ◽  
Vol 26 (S2) ◽  
pp. 2122-2122
Author(s):  
J. Webster ◽  
M. Kaushik ◽  
E. Prandovszky ◽  
G. McConkey
Keyword(s):  
Toxoplasma Gondii ◽  
Predation Risk ◽  
Dopamine Synthesis ◽  
Mammalian Host ◽  
Dopamine Antagonist ◽  
Rate Limiting Step ◽  
Brain Cysts ◽  
Host Behaviour ◽  
The Impact

IntroductionRecognition of the role of infectious agents in a range of both acute and chronic diseases is increasing. One key example is the potential epidemiological and neuropathological association between some cases of schizophrenia with the protozoan Toxoplasma gondii. T. gondii establishes persistent infection within the CNS and can alter host behaviour. Altered dopamine levels have been reported for both T. gondii infection and schizophrenia. Several medications used to treat schizophrenia demonstrate anti-T. gondii properties, and haloperidol, a dopamine antagonist, can prevent the development of T. gondii-altered behaviour in rodents. Furthermore, T. gondii may actually be a source of dopamine, as it encodes a copy of the mammalian enzyme tyrosine hydroxylase, which represents the rate-limiting step in dopamine synthesis.AimsUsing the epidemiologically and clinically applicable rat-T. gondii model, and incorporating a battery of classical and novel non-invasive behavioural and physiological assays, we aim to further elucidate the impact of T. gondii on behaviour and the mechanisms involved.ResultsT. gondii increases the rats’ propensity for predation risk through enhanced activity, visibility and manipulation of their perception of predation risk, turning innate aversion into a ‘suicidal’ feline attraction. There is little indication that T. gondii alters the rats generalized anxiety, nor potential to enhanced predation by non-definitive mammalian host species. Preliminary associative analyses into the relationship between individual behavioural alterations and neurotransmitter and brain cysts localisation profiles will be presented.ConclusionsOur results provide further evidence for a role of T. gondii in the aetiology of some cases of schizophrenia.

Vorkommen und Genotypen von Toxoplasma gondii in der Muskulatur von Schaf, Rind und Schwein sowie im Katzenkot in der Schweiz

2012 ◽  
Vol 154 (6) ◽  
pp. 251-255 ◽  
Author(s):  
F. C. Frey ◽  
E. A. Berger-Schoch ◽  
C. D. Herrmann ◽  
G. Schares ◽  
N. Müller ◽  
...  
Keyword(s):  
Toxoplasma Gondii

Altered visual attention behavior of Toxoplasma gondii-infected individuals.

2019 ◽  
Vol 12 (4) ◽  
pp. 485-494
Author(s):  
Joaquim C. Rossini ◽  
Carolina S. Lopes ◽  
Fernanda P. Dirscherl ◽  
Deise A. O. Silva ◽  
José R. Mineo
Keyword(s):  
Toxoplasma Gondii ◽  
Visual Attention

Konnatale Toxoplasmose

2014 ◽  
Vol 14 (02) ◽  
pp. 101-106
Author(s):  
C. Feiterna-Sperling
Keyword(s):  
Toxoplasma Gondii

ZusammenfassungBei einer primären Toxoplasmose in der Schwangerschaft besteht für den Fetus das Risiko einer konnatalen Infektion durch diaplazentare Transmission von Toxoplasma gondii. Das Risiko einer fetalen Infektion nimmt dabei mit der Schwangerschaftsdauer zu, während die Schwere der Symptomatik mit zunehmendem Gestationsalter abnimmt. Bei den meisten infizierten Neugeborenen finden sich klinisch inapparente Infektionen, aber auch postnatal unauffällige Kinder sind einem Risiko von späteren Folgeschäden ausgesetzt. Neben neurologischen Entwicklungsstörungen ist vor allem das Risiko einer Retinochoroiditis von Bedeutung, die sich auch erst im späteren Leben manifestieren kann. Eine frühzeitige Erkennung einer Primärinfektion in der Schwangerschaft ist Voraussetzung, um durch eine frühzeitige anti-parasitäre Therapie, das Risiko einer fetalen Schädigung zu reduzieren. Durch eine post-natale Therapie kann vermutlich zusätzlich das Risiko der Langzeitkomplikationen gesenkt werden. Neugeborene mit Verdacht auf eine konnatale Toxoplasmose müssen sorgfältig hinsichtlich einer konnatalen Infektion untersucht werden und Säuglinge mit einer gesicherten Infektion benötigen langfristige Nachuntersuchungen hinsichtlich möglicher Spätschäden, insbesondere der Manifestation einer Retinochoroiditis.

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