kynurenic acid

Neurobiological studies on the relationship between toxoplasmosis and neuropsychiatric diseases

October 9, 2015
Fabiani, S., Pinto, B., Bonuccelli, U., Bruschi, F.
Journal of the Neurological Sciences 2015; 35:3-8

Click for abstract

Toxoplasma gondii is a widespread protozoan parasite infecting approximately one third of the world population. After proliferation of tachyzoites during the acute stage, the parasite forms tissue cysts in various anatomical sites including the Central Nervous tissue, and establishes a chronic infection. Clinical spectrum normally ranges from a completely asymptomatic infection to severe multi-organ involvement. Many studies have suggested T. gondii infection as a risk factor for the development of some neuropsychiatric disorders, particularly schizophrenia. During the last years, a potential link with other neurobiological diseases such as Parkinson disease and Alzheimer disease has also been suggested. This review will focus on neurobiological and epidemiological data relating infection with T. gondii to neuropsychiatric diseases. (C) 2015 Elsevier B.V. All rights reserved.

Tagged: 1st-episode schizophrenia, brain, encephalitis, expression, gondii infection, immune-response, kynurenic acid, mechanisms, neurobiology, neurological diseases, neurotransmitter pathway, risk behavior, schizophrenia spectrum disorders, seroprevalence, t. gondii

Mental health

The association of Toxoplasma gondii infection with neurocognitive deficits in a population-based analysis

October 10, 2014
Pearce, B.D., Kruszon-Moran, D., Jones, J.L.
Social Psychiatry and Psychiatric Epidemiology 2014; 49: 1001-1010

Click for abstract

To examine the relationship between infection with Toxoplasma gondii (toxo) and cognition. Multivariate logistic regression was used to test the association of toxo seropositivity with indices of cognitive function among over 4,200 adults in the third National Health and Nutrition Examination Survey. Toxo-seropositive participants were more likely than seronegative participants to score in the worst quartile of the simple reaction time test (OR 1.3, 95 % CI 1.0, 1.6), symbol-digit substitution test (SDST, OR 1.5, 95 % CI 1.2, 1.9) and the serial-digit learning test (trials to criterion) (SDLTNT, OR 1.4, 95 % CI 1.1, 1.8) in models adjusted for age, race/ethnicity, gender and foreign birth. After further adjustment for all cofactors, the association between toxo seropositivity and these outcomes was no longer significant. However, seropositivity was associated with worse scores on the SDST (OR 2.9, 95 % CI 1.8, 4.8) among those in the lowest income category and the SDLTNT (OR 1.5, 95 % CI 1.1, 2.5) among those foreign born. Toxo seropositivity may be associated with poor cognitive test scores in certain subgroups; however, causation cannot be established in this cross-sectional study.

Tagged: behavioral-changes, cognition, cognitive function, infection, kynurenic acid, national-health, neurobehavioral test-performance, neuroimmunology, nhanes-iii, nutrition examination, population-based study, risk factors, survey 3rd, traffic accidents, united-states

Cognitive functions Mental health

Toxoplasma gondii and cognitive deficits in schizophrenia: An animal model perspective

October 12, 2012
Kannan, G., Pletnikov, M.V.
Schizophrenia Bulletin 2012; 38: 1155-1161

Click for abstract

Cognitive deficits are a core feature of schizophrenia. Epidemiological evidence indicates that microbial pathogens may contribute to cognitive impairment in patients with schizophrenia. Exposure to Toxoplasma gondii (T. gondii) has been associated with cognitive deficits in humans. However, the mechanisms whereby the parasite impacts cognition remain poorly understood. Animal models of T. gondii infection may aid in elucidating the underpinnings of cognitive dysfunction. Here, we (1) overview the literature on the association of T. gondii infection and cognitive impairment, (2) critically analyze current rodent models of cognitive deficits resulting from T. gondii infection, and (3) explore possible mechanisms whereby the parasite may affect cognitive function.

Tagged: congenital toxoplasmosis, cytomegalovirus-infection, gene-environment interactions, herpes-simplex, immune system, infection, kynurenic acid, kynurenine, laboratory rats, latent toxoplasmosis, learning and memory, mice behavior, novelty discrimination, tissue cysts, Toxoplasma

Cognitive functions Mental health

Latent toxoplasmosis and human

January 10, 2012
Dalimi, A., Abdoli, A.
Iranian Journal of Parasitology 2012; 7: 1-17

Click for abstract

Toxoplasmosis is one of the most common parasitic diseases worldwide. Although estimated that one third of the world's population are infected with Toxoplasma gondii, but the most common form of the disease is latent (asymptomatic). On the other hand, recent findings indicated that latent toxoplasmosis is not only unsafe for human, but also may play various roles in the etiology of different mental disorders. This paper reviews new findings about importance of latent toxoplasmosis (except in immunocompromised patients) in alterations of behavioral parameters and also its role in the etiology of schizophrenia and depressive disorders, obsessive compulsive disorder, Alzheimer's diseases and Parkinson's disease, epilepsy, headache and or migraine, mental retardation and intelligence quotients, suicide attempt, risk of traffic accidents, sex ratio and some possible mechanisms of T gondii that could contribute in the etiology of these alterations.

Tagged: 1st-episode schizophrenia, alzheimers-disease, behavioral parameter, congenital toxoplasmosis, cryptogenic epilepsy, gondii infection, kynurenic acid, mental disorder, parasite toxoplasma, parkinson's disease, serum interleukin-6, taxoplasma gondii, toxoplasmosis, traffic accidents

Behavior Cognitive functions Mental health Reviews

Toxoplasma gondii antibody titers and history of suicide attempts in patients with schizophrenia

October 16, 2011
Okusaga, O,. Langenberg, P., Sleemi, A., Vaswani, D., Giegling, I., Hartmann, A. M., Konte, B., Friedl, M., Groer, M. W., Yolken, R. H., Rujescu, D., Postolache, T. T.
Schizophrenia Research 2011; 133: 150-155

Click for abstract

Toxoplasma gondii (T. gondii) a widespread neurotropic parasite, has been previously associated with schizophrenia and more recently with suicidal behavior. However, no previous study has examined the association of T. gondii with suicidal behavior in schizophrenia patients. 950 individuals diagnosed with schizophrenia by SCID were recruited from the Munich area of Germany. Solid-enzyme immunoassay methods were used to measure IgG plasma antibodies to T. gondii, other neurotropic pathogens and gliadin. Logistic regression models were developed to analyze the association of T. gondii seropositivity or serointensity with history of suicidal behavior. In those younger than the median age of the sample, 38, T. gondii serointensity was associated with history of suicidal behavior (p = 0.02), while in the older patients the relationship was not significant (p = 0.21). Seropositivity was also associated with history of suicide attempt in younger patients, odds ratio 1.59 (95% CI 1.06 to 2.40), p = 0.03. Seropositivity for CMV (p = 0.22), HSV-1 (p = 0.36) and gliadin (p = 0.92) was not related to history of suicide attempt in the entire sample or any age subgroup. T. gondii serology might become, with interaction with vulnerability genes, a candidate biomarker for a subgroup of schizophrenia patients prone to attempting suicide

Tagged: behavior, Cerebral toxoplasmosis, endophenotypes, gene-expression, infection, kynurenic acid, lifetime risk, psychosis, reactivation, Schizophrenia, suicidal-behavior, Toxoplasma gondii, united-states

Behavior Mental health

Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

kynurenic acid

Neurobiological studies on the relationship between toxoplasmosis and neuropsychiatric diseases

The association of Toxoplasma gondii infection with neurocognitive deficits in a population-based analysis

Toxoplasma gondii and cognitive deficits in schizophrenia: An animal model perspective

Latent toxoplasmosis and human

Toxoplasma gondii antibody titers and history of suicide attempts in patients with schizophrenia