White matter microstructure correlates of mathematical giftedness and intelligence quotient

Recent functional neuroimaging studies have shown differences in brain activation between mathematically gifted adolescents and controls. The aim of this study was to investigate the relationship between mathematical giftedness, intelligent quotient (IQ), and the microstructure of white matter tracts in a sample composed of math‐gifted adolescents and aged‐matched controls. Math‐gifted subjects were selected through a national program based on detecting enhanced visuospatial abilities and creative thinking. We used diffusion tensor imaging to assess white matter microstructure in neuroanatomical connectivity. The processing included voxel‐wise and region of interest‐based analyses of the fractional anisotropy (FA), a parameter which is purportedly related to white matter microstructure. In a whole‐sample analysis, IQ showed a significant positive correlation with FA, mainly in the corpus callosum, supporting the idea that efficient information transfer between hemispheres is crucial for higher intellectual capabilities. In addition, math‐gifted adolescents showed increased FA (adjusted for IQ) in white matter tracts connecting frontal lobes with basal ganglia and parietal regions. The enhanced anatomical connectivity observed in the forceps minor and splenium may underlie the greater fluid reasoning, visuospatial working memory, and creative capabilities of these children. Hum Brain Mapp 35:2619–2631, 2014. © 2013 Wiley Periodicals, Inc.     

Prediction of eye and hair pigmentation phenotypes using the HIrisPlex system in a Brazilian admixed population sample

International Journal of Legal Medicine - Human pigmentation is a complex trait, probably involving more than 100 genes. Predicting phenotypes using SNPs present in those genes is important for...     

Altered serotonin 1A binding in major depression: a [carbonyl-C-11]WAY100635 positron emission tomography study.

BACKGROUND: Serotonin 1A receptors (5-HT(1A)) are implicated in the pathophysiology of major depressive disorder (MDD) and in the action of selective serotonin reuptake inhibitors (SSRI). SSRI desensitize 5-HT(1A) and down-regulate 5-HT transporters (5-HTT) with the latter persisting for weeks after discontinuation of SSRI. MDD subjects are more likely to be homozygous for the functional 5-HT(1A) G(-1019) allele of the promoter polymorphism and are postulated to have higher 5-HT(1A) than healthy volunteers (controls). We measure 5-HT(1A) in MDD, assess the effects of antidepressant exposure (AE), and examine the role of the C(-1019)G polymorphism. METHODS: Genotyped and determined 5-HT(1A) binding potential (BP) by positron emission tomography (PET) using [carbonyl-C-11]-WAY-100635 in 28 medication-free MDD subjects during a current major depressive episode and 43 controls. RESULTS: No difference in BP between controls and MDD subjects (p = .235). There was a difference in BP comparing the controls, antidepressant naive (AN) MDD subjects, and subjects with AE across all regions (p = .013). Post hoc testing reveals higher BP in AN compared to controls (p = .008) and to AE (p = .007). The GG genotype is overrepresented in MDD subjects (p = .059), and BP appears higher with the G allele. CONCLUSIONS: AN have higher 5-HT(1A) than controls and AE suggesting a model of depression characterized by an over expression of autoinhibitory somatodendritic 5-HT(1A) receptors, perhaps due to the higher expressing G allele, that may result in reduced terminal field 5-HT release. AE appears to have long-term effects on 5-HT(1A).     

Antipsychotics in children and adolescents: Increasing use, evidence for efficacy and safety concerns

Second-generation antipsychotics (SGA) are increasingly used to treat children and adolescents. The European College of Neuro-psychopharmacology convened an expert panel to review relevant efficacy and safety data, and identify needs for further research. Controlled studies support the short-term efficacy of several SGA for treating psychosis, mania, and aggression within certain diagnostic categories. Except for clozapine, no clinically significant superiority in efficacy has been demonstrated for any specific antipsychotic, including both first- and second-generation agents, in children and adolescents. Major differences exist, however, with respect to type and severity of adverse effects; therefore the choice of treatment is primarily guided by tolerability and safety considerations. Children appear to be at higher risk than adults for a number of adverse effects, such as extrapyramidal symptoms and metabolic and endocrine abnormalities. While the safety profile during acute and intermediate treatment has been evaluated, the distal benefit/risk ratio during long-term treatment remains to be determined. Research is also needed to understand the mechanisms underlying antipsychotic-induced toxicities in order to develop effective preventive and treatment strategies.