[show abstract][hide abstract] ABSTRACT: Trisomy for human chromosome 21 results in Down syndrome (DS), which is among the most complex genetic perturbations leading to intellectual disability. Accumulating data suggest that overexpression of the dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A), is a critical pathogenic mechanisms in the intellectual deficit.
Here we show that the green tea flavonol epigallocatechin-gallate (EGCG), a DYRK1A inhibitor, rescues the cognitive deficits of both segmental trisomy 16 (Ts65Dn) and transgenic mice overexpressing Dyrk1A in a trisomic or disomic genetic background, respectively. It also significantly reverses cognitive deficits in a pilot study in DS individuals with effects on memory recognition, working memory and quality of life. We used the mouse models to ensure that EGCG was able to reduce DYRK1A kinase activity in the hippocampus and found that it also induced significant changes in plasma homocysteine levels, which were correlated with Dyrk1A expression levels. Thus, we could use plasma homocysteine levels as an efficacy biomarker in our human study.
We conclude that EGCG is a promising therapeutic tool for cognitive enhancement in DS, and its efficacy may depend of Dyrk1A inhibition.
Molecular Nutrition & Food Research 09/2013; · 4.31 Impact Factor
[show abstract][hide abstract] ABSTRACT: The retrogenesis model states that the progression of brain aging and Alzheimer's disease (AD) deterioration proceeds inversely to human ontogenic acquisition patterns. Our aim was to assess if the progressive decline of cognitive abilities and functional capacity in AD follows an inverse sequence of acquisition compared to normal developmental patterns. One hundred eighty one children ranging in age from 4 to 12 years and 148 adults (cognitively normal, subjects with mild cognitive impairment, and mild-moderately severe AD) were assessed with the same cognitive and functional tools. The statistical analyses showed a progressive and inverse distribution on cognitive, functional, and mental age scores when comparing results of children classified by chronological age and patients by dementia staging. The pattern of cognitive acquisition in children showed a progressive development of overall cognitive function along all age ranges, in addition to a simultaneous acquisition of instrumental and basic daily living activities in the functional domain. AD patients showed a progressive decline in cognitive and functional domains, which concurs with the sequence of impairment reported in this dementia. Our findings provide support to the inverse and progressive pattern of functional and cognitive decline observed in AD patients compared to the developmental acquisition of these capacities in children, as stated by the retrogenesis model. Nonetheless, certain differences should be considered when comparing the sequence of acquisition during ontogenic development with that of progressive loss during the course of AD. Retrogenesis may account for the progressive loss of neocortical-related functions in AD.
Journal of Alzheimer's disease: JAD 09/2012; · 4.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: There is important preclinical evidence of the long-lasting neurotoxic and selective effects of ecstasy (MDMA) on serotonin systems in nonhuman primates. In humans, long-term recreational use of ecstasy has been mainly associated with memory impairment.
The first aim of our study was to evaluate the cognitive and electrophysiological long-term alterations associated with lifetime ecstasy use within a sample of ecstasy polydrug users along a 1-year follow-up. Our second aim was to explore the relationship between specific cognitive functions and P300 (P3) event-related potentials (ERPs) in ecstasy users.
We conducted auditory P3 latency and amplitude and administered a battery of cognitive tests to three groups of subjects: 14 current ecstasy polydrug users, 13 current cannabis users, and 22 controls free of illicit drugs in two evaluations during 1 year.
We found significant differences between ecstasy users and controls on cognitive measures of word fluency, processing speed, and memory recognition after 1-year follow-up. We found no significant differences between ecstasy and cannabis users or cannabis users and controls on cognitive tests. Lifetime ecstasy use was associated with poorer memory recognition. No group differences were shown on P3 latency or amplitude. Significant correlations emerged between P3 latency and cannabis lifetime use (higher cannabis use was related to faster latency, showing a paradoxical effect) but not with ecstasy exposure.
Our findings provide evidence of mild long-term cognitive deficits among ecstasy polydrug users. Both ecstasy use and the dynamic interaction between ecstasy and cannabis effects may account for these deficits. No significant P3 alterations were found in ecstasy users.
[show abstract][hide abstract] ABSTRACT: The Mini-Mental State Examination is one of the most widely used screening tests for the adult population in daily neurologic practice. The aim of this study was to describe and to analyze the results of the Mini-Mental State Examination administered to Spanish children and to assess the relationship between Mini-Mental State Examination scores and the child's mental age/intelligence quotient. The study population included 181 children whose ages ranged between 4 and 12 years. The neuropsychologic battery consisted of the Mini-Mental State Examination and Kaufman Brief Intelligence Test. Percentiles were obtained for the Mini-Mental State Examination total score according to age ranges. Performance gradually increased from 4 to 10 years of age when a plateau in the total Mini-Mental State Examination score was reached. At the age of 6 years, results exceeded 24 on average. Pairwise mean comparisons showed statistically significant differences between the age groups (P < .05). Data distribution could be classified in 4 independent groups for the following chronologic ages: 4, 5, and 6 years and from 7 to 12 years of age. The total Mini-Mental State Examination score correlated significantly with the child's chronologic (r = 0.80, P < .001) and mental (r = 0.76, P < .001) ages. This is a preliminary study of the application of the Mini-Mental State Examination in a Spanish child population as well as a first step for the assessment of the usefulness of this instrument as a cognitive screening tool for children's development.
Journal of Child Neurology 11/2007; 22(11):1269-73. · 1.39 Impact Factor