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Find video protocols related to scientific articles indexed in Pubmed.
Genetic variation in the G72 gene is associated with increased frontotemporal fiber tract integrity.
Eur Arch Psychiatry Clin Neurosci
PUBLISHED: 02-19-2014
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G72 (syn. DAOA, D-amino acid oxidase activator) is a susceptibility gene for both schizophrenia and bipolar disorder. Diffusion tensor imaging studies hint at changes in fiber tract integrity in both disorders. We aimed to investigate whether a G72 susceptibility haplotype causes changes in fiber tract integrity in young healthy subjects. We compared fractional anisotropy in 47 subjects that were either homozygous for the M23/M24 risk haplotype (n = 20) or homozygous for M23(rs3918342)/M24(rs1421292) wild type (n = 27) using diffusion tensor imaging with 3 T. Tract-based spatial statistics, a method especially developed for diffusion data analysis, was used to delineate the major fiber tracts. We found clusters of increased FA values in homozygous risk haplotype carriers in the right periinsular region and in the right inferior parietal lobe (IPL). We did not find clusters indicating decreased FA values. The insula and the IPL have been implicated in both schizophrenia and bipolar pathophysiology. Increased FA values might reflect changes in dendritic morphology as previously described by in vitro studies. These findings further corroborate the hypothesis that a shared gene pool between schizophrenia and bipolar disorder might lead to neuroanatomic changes that confer an unspecific vulnerability for both disorders.
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A Neuregulin-1 schizophrenia susceptibility variant causes perihippocampal fiber tract anomalies in healthy young subjects.
Brain Behav
PUBLISHED: 01-19-2014
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Changes in fiber tract architecture have gained attention as a potentially important aspect of schizophrenia neuropathology. Although the exact pathogenesis of these abnormalities yet remains to be elucidated, a genetic component is highly likely. Neuregulin-1 (NRG1) is one of the best-validated schizophrenia susceptibility genes. We here report the impact of the Neuregulin-1 rs35753505 variant on white matter structure in healthy young individuals with no family history of psychosis.
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The impact of a Dysbindin schizophrenia susceptibility variant on fiber tract integrity in healthy individuals: a TBSS-based diffusion tensor imaging study.
Neuroimage
PUBLISHED: 06-10-2011
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Schizophrenia is a severe neuropsychiatric disorder with high heritability, though its exact etiopathogenesis is yet unknown. An increasing number of studies point to the importance of white matter anomalies in the pathophysiology of schizophrenia. While several studies have identified the impact of schizophrenia susceptibility gene variants on gray matter anatomy in both schizophrenia patients and healthy risk variant carriers, studies dealing with the impact of these gene variants on white matter integrity are still scarce. We here present a study on the effects of a Dysbindin schizophrenia susceptibility gene variant on fiber tract integrity in healthy young subjects. 101 subjects genotyped for Dysbindin-gene variant rs1018381, though without personal or first degree relative history of psychiatric disorders underwent diffusion tensor imaging (DTI), 83 of them were included in the final analysis. We used Tract-Based Spatial Statistics (TBSS) analysis to delineate the major fiber tracts. Carriers of the minor allele T of the rs1018381 in the Dysbindin gene showed two clusters of reduced fractional anisotropy (FA) values in the perihippocampal region of the right temporal lobe compared to homozygote carriers of the major allele C. Clusters of increased FA values in T-allele carriers were found in the left prefrontal white matter, the right fornix, the right midbrain area, the left callosal body, the left cerebellum and in proximity of the right superior medial gyrus. Dysbindin has been implicated in neurite outgrowth and morphology. Impairments in anatomic connectivity as found associated with the minor Dysbindin allele in our study may result in increased risk for schizophrenia due to altered fiber tracts.
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The effects of a DTNBP1 gene variant on attention networks: an fMRI study.
Behav Brain Funct
PUBLISHED: 03-29-2010
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Attention deficits belong to the main cognitive symptoms of schizophrenia and come along with altered neural activity in previously described cerebral networks. Given the high heritability of schizophrenia the question arises if impaired function of these networks is modulated by susceptibility genes and detectable in healthy risk allele carriers.
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COMT genotype and its role on hippocampal-prefrontal regions in declarative memory.
Neuroimage
PUBLISHED: 01-11-2010
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Memory dysfunction is a prominent feature in schizophrenia. Impairments of declarative memory have been consistently linked to alterations especially within hippocampal-prefrontal regions. Due to the high heritability of schizophrenia, susceptibility genes and their modulatory impact on the neural correlates on memory are of major relevance. In the present study the influence of the COMT val(158)met status on the neural correlates of declarative memory was investigated in healthy subjects.
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The effect of G72 genotype on neural correlates of memory encoding and retrieval.
Neuroimage
PUBLISHED: 08-31-2009
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Polymorphisms in the G72 (also named d-amino acid oxidase activator, DAOA) gene increase the vulnerability for schizophrenia and affective psychosis. Three recent genetic neuroimaging studies showed that variation in G72 influences the brain activity in the medial temporal lobe (MTL), supporting the hypothesis that G72 might play a modulatory role on brain activity in MTL structures. In the present study we therefore investigated the effect of G72 on the neural correlates of long-term memory encoding and retrieval in a large sample of healthy subjects (n=83) using functional magnetic resonance imaging. A face encoding and a face retrieval memory task were chosen because on the one hand they specifically activate MTL structures and on the other hand they tap into memory processes that are compromised in patients with schizophrenia and affective disorder. Despite a strong a-priori hypothesis of genotype group activation differences in the MTL along with a large sample size we did neither find an effect of G72 genotype status on brain activity in the MTL nor in any other brain regions. The present data therefore do not support the view of a general modulatory role of G72 on MTL brain activity, at least not in the domain of long-term memory encoding and retrieval. Our results highlight the importance of replication studies in genetic neuroimaging.
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The effect of Neuregulin 1 on neural correlates of episodic memory encoding and retrieval.
Neuroimage
PUBLISHED: 07-14-2009
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Neuregulin 1 (NRG1) has been found to be associated with schizophrenia. Impaired performance in episodic memory tasks is an often replicated finding in this disorder. In functional neuroimaging studies, this dysfunction has been linked to signal changes in prefrontal and medial temporal areas. Therefore, it is of interest whether genes associated with the disorder, such as NRG1, modulate episodic memory performance and its neural correlates. Ninety-four healthy individuals performed an episodic memory encoding and a retrieval task while brain activation was measured with functional MRI. All subjects were genotyped for the single nucleotide polymorphism (SNP) rs35753505 in the NRG1 gene. The effect of genotype on brain activation was assessed with fMRI during the two tasks. While there were no differences in performance, brain activation in the cingulate gyrus (BA 24), the left middle frontal gyrus (BA 9), the bilateral fusiform gyrus and the left middle occipital gyrus (BA 19) was positively correlated with the number of risk alleles in NRG1 during encoding. During retrieval brain activation was positively correlated with the number of risk alleles in the left middle occipital gyrus (BA 19). NRG1 genotype does modulate brain activation during episodic memory processing in key areas for memory encoding and retrieval. The results suggest that subjects with risk alleles show hyperactivations in areas associated with elaborate encoding strategies.
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Effect of CACNA1C rs1006737 on neural correlates of verbal fluency in healthy individuals.
Neuroimage
PUBLISHED: 07-08-2009
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Recent genetic studies found the A allele of the variant rs1006737 in the alpha 1C subunit of the L-type voltage-gated calcium channel (CACNA1C) gene to be overrepresented in patients suffering from bipolar disorder, schizophrenia or major depression. While the functions underlying the pathophysiology of these psychiatric disorders are yet unknown, impaired performance in verbal fluency tasks is an often replicated finding. We investigated the influence of the rs1006737 single nucleotide polymorphism (SNP) on verbal fluency and its neural correlates.
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Subclinical hypothyroidism after radioiodine exposure: Ukrainian-American cohort study of thyroid cancer and other thyroid diseases after the Chornobyl accident (1998-2000).
Environ. Health Perspect.
PUBLISHED: 05-30-2009
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Hypothyroidism is the most common thyroid abnormality in patients treated with high doses of iodine-131 (131I). Data on risk of hypothyroidism from low to moderate 131I thyroid doses are limited and inconsistent.
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Genetic variation in the schizophrenia-risk gene neuregulin 1 correlates with brain activation and impaired speech production in a verbal fluency task in healthy individuals.
Hum Brain Mapp
PUBLISHED: 04-08-2009
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Impaired performance in verbal fluency tasks is an often replicated finding in schizophrenia. In functional neuroimaging studies, this dysfunction has been linked to signal changes in prefrontal and temporal areas. Since schizophrenia has a high heritability, it is of interest whether susceptibility genes for the disorder, such as NRG1, modulate verbal fluency performance and its neural correlates. Four hundred twenty-nine healthy individuals performed a semantic and a lexical verbal fluency task. A subsample of 85 subjects performed an overt semantic verbal fluency task while brain activation was measured with functional magnetic resonance imaging (MRI). NRG1 (SNP8NRG221533; rs35753505) status was determined and correlated with verbal fluency performance and brain activation. For the behavioral measure, there was a linear effect of NRG1 status on semantic but not on lexical verbal fluency. Performance decreased with number of risk-alleles. In the fMRI experiment, decreased activation in the left inferior frontal and the right middle temporal gyri as well as the anterior cingulate gyrus was correlated with the number of risk-alleles in the semantic verbal fluency task. NRG1 genotype does influence language production on a semantic level in conjunction with the underlying neural systems. These findings are in line with results of studies in schizophrenia and may explain some of the cognitive and brain activation variation found in the disorder. More generally, NRG1 might be one of several genes that influence semantic language capacities.
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The effect of the COMT val(158)met polymorphism on neural correlates of semantic verbal fluency.
Eur Arch Psychiatry Clin Neurosci
PUBLISHED: 03-31-2009
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Variation in the val(158)met polymorphism of the COMT gene has been found to be associated with cognitive performance. In functional neuroimaging studies, this dysfunction has been linked to signal changes in prefrontal areas. Given the complex modulation and functional heterogeneity of frontal lobe systems, further specification of COMT gene-related phenotypes differing in prefrontally mediated cognitive performance are of major interest. Eighty healthy individuals (54 men, 26 women; mean age 23.3 years) performed an overt semantic verbal fluency task while brain activation was measured with functional magnetic resonance imaging (fMRI). COMT val(158)met genotype was determined and correlated with brain activation measured with fMRI during the task. Although there were no differences in performance, brain activation in the left inferior frontal gyrus [Brodmann area 10] was positively correlated with the number of val alleles in the COMT gene. COMT val(158)met status modulates brain activation during the language production on a semantic level in an area related to executive functions.
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Effect of the G72 (DAOA) putative risk haplotype on cognitive functions in healthy subjects.
BMC Psychiatry
PUBLISHED: 03-10-2009
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In the last years, several susceptibility genes for psychiatric disorders have been identified, among others G72 (also named D-amino acid oxidase activator, DAOA). Typically, the high-risk variant of a vulnerability gene is associated with decreased cognitive functions already in healthy individuals. In a recent study however, a positive effect of the high-risk variant of G72 on verbal working memory was reported. In the present study, we therefore examined the relationship between G72 genotype status and a broad range of cognitive functions in 423 healthy individuals.
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A putative high risk diplotype of the G72 gene is in healthy individuals associated with better performance in working memory functions and altered brain activity in the medial temporal lobe.
Neuroimage
PUBLISHED: 01-08-2009
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G72 is a vulnerability gene for schizophrenia and affective psychosis, disorders that are characterized by deficits in working memory. In the present study we investigated whether the G72 genotype influences verbal and spatial working memory functions in healthy individuals. Working memory was assessed at the behavioural level in 423 subjects using the spatial span of the Wechsler Memory Scale (spatial working memory) and the letter-number-span test (verbal working memory). In a sub-sample of 83 subjects, we assessed working memory functions also at the neural level using functional magnetic resonance imaging during a classical letter variant of the n-back task. Unexpectedly the high risk allele carriers performed better in the verbal working memory task than the other subjects. These behavioural differences were accompanied by brain activation differences in the right parahippocampus, a brain region that plays a major role in schizophrenia and affective disorders. The high risk variant of a vulnerability gene therefore does not necessarily have to negatively affect cognitive abilities per se, but may even have beneficial effects on cognitive functions in the non-affected population.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.