memory

Prevalence of toxoplasmosis and its association with dementia in older adults in Central Africa: a result from the EPIDEMCA programme

February 12, 2018
Bouscaren, N., Pilleron,S. , Mbelesso,P. , Ndamba-Bandzouzi,B., Dartigues,J. F. , Clement,J. P. , Preux, P. M., Darde,M. L., Guerchet , M. , Grp, E.
Tropical Medicine and International Health 2018;23: 1304-1313

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Objective We aimed at estimating the seroprevalence of Toxoplasma gondii (T. gondii) infection in older adults living in Central Africa and investigating its association with dementia using data from the Epidemiology of Dementia in Central Africa (EPIDEMCA) programme. Methods A cross-sectional multicentre population-based study was carried out among participants aged 73 (+/- 7) years on average, living in rural and urban areas of the Central African Republic and the Republic of Congo between November 2011 and December 2012. Blood samples were collected from each consenting participant. The detection of anti-T. gondii immunoglobulin G antibodies was performed in 2014 in France using a commercially available ELISA kit. Participants were interviewed using a standardised questionnaire including sociodemographic characteristics. DSM-IV criteria were required for a diagnosis of dementia. Multivariate binary logistic regression models were used to assess the association between toxoplasmosis infection and dementia. Results Among 1662 participants, the seroprevalence of toxoplasmosis was 63.0% (95% confidence interval (CI): 60.7-65.3) overall, 66.6% (95%CI: 63.4-69.8) in Central African Republic and 59.4% (95%CI: 56.1-62.7) in the Republic of Congo. In multivariate analyses, toxoplasmosis status was significantly associated with increasing age (P = 0.006), Republic of Congo (P = 0.002), urban area (P = 0.001) and previous occupation (P = 0.002). No associations between dementia and toxoplasmosis status or anti-T. gondii IgG titres were found. Conclusion Toxoplasma gondii infection was not associated with dementia among older adults in Central Africa. Our findings are consistent with previous studies and add to the knowledge on the relationship between T. gondii infection and neurological disorders.

Tagged: adults, alzheimers-disease, behavior, congo, dementia, genotypes, gondii infection, health, link, memory, older, seroprevalence, sub-saharan africa, Toxoplasma gondii

Cognitive functions

Toxoplasma gondii moderates the association between multiple folate-cycle factors and cognitive function in US adults

October 2, 2017
Berrett, A. N., Gale, S. D., Erickson, L. D., Brown, B. L., Hedges, D. W.
Nutrients 2017; 9

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Toxoplasma gondii (T. gondii) is a microscopic, apicomplexan parasite that can infect muscle or neural tissue, including the brain, in humans. While T. gondii infection has been associated with changes in mood, behavior, and cognition, the mechanism remains unclear. Recent evidence suggests that T. gondii may harvest folate from host neural cells. Reduced folate availability is associated with an increased risk of neurodevelopmental disorders, neurodegenerative diseases, and cognitive decline. We hypothesized that impairment in cognitive functioning in subjects seropositive for T. gondii might be associated with a reduction of folate availability in neural cells. We analyzed data from the third National Health and Nutrition Examination Survey to determine the associations between T. gondii infection, multiple folate-cycle factors, and three tests of cognitive functioning in U.S. adults aged 20 to 59 years. In these analyses, T. gondii moderated the associations of folate, vitamin B-12, and homocysteine with performance on the Serial Digit Learning task, a measure of learning and memory, as well as the association of folate with reaction time. The results of this study suggest that T. gondii might affect brain levels of folate and/or vitamin B-12 enough to affect cognitive functioning.

Tagged: alzheimers-disease, deficiency, disorders, folate cognition, folic-acid, gene, helicobacter-pylori, homocysteine, memory, metaanalysis, metabolism, mthfr gene, polymorphisms, Toxoplasma gondii, united-states, vitamin b-12

Cognitive functions

Association between latent toxoplasmosis and cognition in adults: a cross-sectional study

October 9, 2015
Gale, S. D., Brown, B. L., Erickson, L. D., Berrett, A., Hedges, D. W.
Parasitology 2015; 142: 557-565

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Latent infection from Toxoplasma gondii (T. gondii) is widespread worldwide and has been associated with cognitive deficits in some but not all animal models and in humans. We tested the hypothesis that latent toxoplasmosis is associated with decreased cognitive function in a large cross-sectional dataset, the National Health and Nutrition Examination Survey (NHANES). There were 4178 participants aged 20-59 years, of whom 191% had IgG antibodies against T. gondii. Two ordinary least squares (OLS) regression models adjusted for the NHANES complex sampling design and weighted to represent the US population were estimated for simple reaction time, processing speed and short-term memory or attention. The first model included only main effects of latent toxoplasmosis and demographic control variables, and the second added interaction terms between latent toxoplasmosis and the poverty-to-income ratio (PIR), educational attainment and race-ethnicity. We also used multivariate models to assess all three cognitive outcomes in the same model. Although the models evaluating main effects only demonstrated no association between latent toxoplasmosis and the cognitive outcomes, significant interactions between latent toxoplasmosis and the PIR, between latent toxoplasmosis and educational attainment, and between latent toxoplasmosis and race-ethnicity indicated that latent toxoplasmosis may adversely affect cognitive function in certain groups.

Tagged: attention, behavior, brain, cognition, deficits, disease, gondii infection, memory, Mexico, performance, processing speed, Schizophrenia, seroprevalence, socioeconomic position, Toxoplasma gondii, toxoplasmosis

Cognitive functions

Immediate rather than delayed memory impairment in older adults with latent toxoplasmosis

October 6, 2015
Mendy, A., Vieira, E. R., Albatineh, A. N., Gasana, J.
Brain Behavior and Immunity 2015; 45: 36-40

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The neurotropic parasite Toxoplasma gondii infects one third of the world population, but its effect on memory remains ambiguous. To examine a potential relationship of the infection with immediate and delayed memory, a population-based study was conducted in 4485 participants of the Third National Health and Nutrition Examination Survey aged 60 years and older. Serum anti-Toxoplasma IgG antibodies were measured by enzyme immune assay and verbal memory was assessed using the Mini-Mental State Examination and the East Boston Memory Test. The prevalence of latent toxoplasmosis was 41%; in one way analysis of variance, anti-Toxoplasma IgG antibody levels significantly differed across tertiles for immediate (P = 0.006) but not delayed memory scores (P = 0.22). In multinomial logistic regression adjusting for covariates, Toxoplasma seropositivity was associated with lower immediate memory performance (OR: 0.65, 95% CI: 0.44, 0.97 for medium tertile and OR: 0.61, 95% CI: 0.37, 0.98 for highest tertile in reference to the lowest tertile), especially in non-Hispanic Whites (OR: 0.56, 95% CI: 0.36, 0.88 for medium tertile and OR: 0.51, 95% CI: 0.30, 0.87 for highest tertile in reference to the lowest tertile). However, no relationship with delayed memory was observed. In conclusion, latent toxoplasmosis is widespread in older adults and may primarily affect immediate rather than delayed memory, particularly in White Americans.

Tagged: aging, cognition, gondii infection, memory, mice, older age, rhd molecule, risk, short-term-memory, Toxoplasma gondii, toxoplasmosis

Cognitive functions

Toxoplasma gondii seropositivity and cognitive functions in school-aged children

October 6, 2015
Mendy, A., Vieira, E. R., Albatineh, A. N., Gasana, J.
Parasitology 2015; 142: 1221-1227

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Toxoplasma gondii (T. gondii) infects one-third of the world population, but its association with cognitive functions in school-aged children is unclear. We examined the relationship between Toxoplasma seropositivity and neuropsychological tests scores (including math, reading, visuospatial reasoning and verbal memory) in 1755 school-aged children 12-16 years old who participated to the Third National Health and Nutrition Examination Survey, using multiple linear regressions adjusted for covariates. Toxoplasma seroprevalence was 7.7% and seropositivity to the parasite was associated with lower reading skills (regression coefficient [beta] = -5.86, 95% confidence interval [CI]: -11.11, -0.61, P = 0.029) and memory capacities (beta = -0.86, 95% CI: -1.58, -0.15, P = 0.017). The interaction between T. gondii seropositivity and vitamin E significantly correlated with memory scores. In subgroup analysis, Toxoplasma-associated memory impairment was worse in children with lower serum vitamin E concentrations (beta = -1.61, 95% CI: -2.44, -0.77, P < 0.001) than in those with higher values (beta = -0.12, 95% CI: -1.23, 0.99, P = 0.83). In conclusion, Toxoplasma seropositivity may be associated with reading and memory impairments in school-aged children. Serum vitamin E seems to modify the relationship between the parasitic infection and memory deficiency.

Tagged: adults, association, behavior, cognition, cognitive function, disease, Dopamine, gene-expression, infection, intelligence, math, memory, mice, parasites, performance, reading, school-aged children, Toxoplasma gondii, vitamin e, vitamins

Cognitive functions

Toxoplasma gondii impairs memory in infected seniors

October 10, 2014
Gajewski, P. D., Falkenstein, M., Hengstler, J. G., Golka, K.
Brain Behavior and Immunity 2014; 36: 193-199

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lmost 30% of humans present a Toxoplasma gondii positive antibody status and its prevalence increases with age. The central nervous system is the main target. However, little is known about the influence of asymptomatic i.e. latent Toxoplasmosis on cognitive functions in humans. To investigate neurocognitive dysfunctions in asymptomatic older adults with T. gondii positive antibody status a double-blinded neuropsychological study was conducted. The participants were classified from a population-based sample (N = 131) of healthy participants with an age of 65 years and older into two groups with 42 individuals each: Toxoplasmosis positive (T-pos; IgG > 50 IU/ml) and Toxoplasmosis negative (T-neg; IgG = 0 IU/ml). The outcome measures were a computer-based working-memory test (2-back) and several standardized psychometric tests of memory and executive cognitive functions. T-pos seniors showed an impairment of different aspects of memory. The rate of correctly detected target symbols in a 2-back task was decreased by nearly 9% (P = 0.020), corresponding to a performance reduction of about 35% in working memory relative to the T-neg group. Moreover, T-pos seniors had a lower performance in a verbal memory test, both regarding immediate recall (10% reduction; P = 0.022), delayed recognition (6%; P = 0.037) and recall from long-term memory assessed by the word fluency tests (12%; P = 0.029). In contrast, executive functions were not affected. The effects remained mostly unchanged after controlling for medication. The impairment of memory functions in T-pos seniors was accompanied by a decreased self-reported quality of life. Because of the high prevalence of asymptomatic Toxoplasmosis and an increasing population of older adults this finding is of high relevance for public health

Tagged: age, aging, behavior, challenges, cognition, Dopamine, humans, load, memory, performance, rats, task, Toxoplasma gondii, vaccines, working memory

Cognitive functions

The relation of cortisol and sex hormone levels to results of psychological, performance, IQ and memory tests in military men and women

January 9, 2012
Flegr, J., Hampl, R., Černochová, D., Preiss, M., Bičíkova, M., Sieger, L., Příplatová, L., Kaňková, S., Klose, J.
Neuroendocrinology Letters 2012; 33: 224-235

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BACKGROUND: Cortisol, along with other hormones of hypothalamo-pituitary-adrenal axis, belongs to one of the main factors influencing psychological and pathognomic factors, intelligence, and memory. METHODS: The aim of our study was to review a large battery of psychological, performance, IQ and memory tests as to their relation with cortisol, testosterone and estrogen levels in groups of 100 men and 93 women who attended the Central Military Hospital in Prague for regular entrance psychological examinations for military personnel. RESULTS: In men, we detected positive correlations between cortisol and emotional lability, and negative correlations with impulsivity, while in women hypochondria and psychopathology were negatively correlated, and aggression measured with the Meili selective memory test had a positive relation to cortisol level. Testosterone correlated positively with emotional liability and negatively with impulsivity in men, and negatively with hypochondria and psychasteny, indirect aggression, irritability and paranoia in women. Estradiol correlated positively with psychopathology in men, and negatively with phobia. It was positively correlated with negativism in women. No clear correlation was observed between the concentration of steroid hormones and psychomotor performance or intelligence. CONCLUSIONS: Concentrations of steroid hormones correlate with results of several psychological tests, the sign and magnitude of these correlations, however, very often differ in military men and women.

Tagged: aggression, bdi, behavior, cortisol, dominance, estrogen, gender differences, hypothesis, intelligence, meili test, memory, miller 2009, n-70, od-1, otis test, personality, personality tests, psychology, questionnaire, responses, stress, supports, testosterone, testosterone concentration, topp, toxoplasmosis, wmt

Cognitive functions Personality

Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

memory

Prevalence of toxoplasmosis and its association with dementia in older adults in Central Africa: a result from the EPIDEMCA programme

Toxoplasma gondii moderates the association between multiple folate-cycle factors and cognitive function in US adults

Association between latent toxoplasmosis and cognition in adults: a cross-sectional study

Immediate rather than delayed memory impairment in older adults with latent toxoplasmosis

Toxoplasma gondii seropositivity and cognitive functions in school-aged children

Toxoplasma gondii impairs memory in infected seniors

The relation of cortisol and sex hormone levels to results of psychological, performance, IQ and memory tests in military men and women