Abnormal brain synchrony in Down Syndrome

Anderson, Jeffrey S.; Nielsen, Jared A.; Ferguson, Michael; Burback, Melissa C.; Cox, Elizabeth; Dai, Li; Gerig, Guido; Edgin, Jamie O.; Korenberg, Julie R.

doi:10.1016/j.nicl.2013.05.006

Cited by 120 publications

(176 citation statements)

References 75 publications

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“…Brain regions that are typically negatively correlated, such as DMN regions and regions comprising the DAN and frontoparietal network, were found to be less (negatively) correlated in individuals with DS. A functional parcellation of the brain showed a simplified network structure in DS, characterized by increased between-network connectivity, particularly in networks with shorter-range connections, which was not observed in an autism comparison sample with normal IQ (Anderson et al, 2013). The authors suggest that their findings indicate immature development of connectivity in DS with impaired ability to integrate information from distant brain regions into coherent distributed networks.…”

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confidence: 82%

“…Anderson et al (2013) compared functional connectivity in 15 individuals with DS to 14 TD control subjects while they viewed 50 min of cartoon video clips and found that individuals with DS exhibited higher levels of connectivity between most brain regions. Brain regions that are typically negatively correlated, such as DMN regions and regions comprising the DAN and frontoparietal network, were found to be less (negatively) correlated in individuals with DS.…”

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confidence: 99%

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Resting-State Functional Connectivity in Individuals with Down Syndrome and Williams Syndrome Compared with Typically Developing Controls

et al. 2015

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The emergence of resting-state functional connectivity (rsFC) analysis, which examines temporal correlations of low-frequency ( < 0.1 Hz) blood oxygen level-dependent signal fluctuations between brain regions, has dramatically improved our understanding of the functional architecture of the typically developing (TD) human brain. This study examined rsFC in Down syndrome (DS) compared with another neurodevelopmental disorder, Williams syndrome (WS), and TD. Ten subjects with DS, 18 subjects with WS, and 40 subjects with TD each participated in a 3-Tesla MRI scan. We tested for group differences (DS vs. TD, DS vs. WS, and WS vs. TD) in between-and within-network rsFC connectivity for seven functional networks. For the DS group, we also examined associations between rsFC and other cognitive and genetic risk factors. In DS compared with TD, we observed higher levels of between-network connectivity in 6 out 21 network pairs but no differences in within-network connectivity. Participants with WS showed lower levels of within-network connectivity and no significant differences in between-network connectivity relative to DS. Finally, our comparison between WS and TD controls revealed lower within-network connectivity in multiple networks and higher betweennetwork connectivity in one network pair relative to TD controls. While preliminary due to modest sample sizes, our findings suggest a global difference in between-network connectivity in individuals with neurodevelopmental disorders compared with controls and that such a difference is exacerbated across many brain regions in DS. However, this alteration in DS does not appear to extend to within-network connections, and therefore, the altered between-network connectivity must be interpreted within the framework of an intact intra-network pattern of activity. In contrast, WS shows markedly lower levels of within-network connectivity in the default mode network and somatomotor network relative to controls. These findings warrant further investigation using a taskbased procedure that may help disentangle the relationship between brain function and cognitive performance across the spectrum of neurodevelopmental disorders.

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confidence: 82%

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confidence: 99%

Resting-State Functional Connectivity in Individuals with Down Syndrome and Williams Syndrome Compared with Typically Developing Controls

et al. 2015

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“…These include a reduction in the numbers of neurons and dendritic spines, dendritic arborization, an alteration in the excitatory-inhibitory balance and a global impairment in network connectivity 68,[162][163][164][165][166] . These perturbations in the structure, function and organization of the CNS may profoundly affect its degeneration in AD-DS (BOX 1).…”

Section: Neuronal Development and Functionmentioning

confidence: 99%

A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome

et al. 2015

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Down syndrome, which arises in individuals carrying an extra copy of chromosome 21, is associated with a greatly increased risk of early-onset Alzheimer disease. It is thought that this risk Europe PMC Funders Author ManuscriptsEurope PMC Funders Author Manuscripts is conferred by the presence of three copies of the gene encoding amyloid precursor protein (APP) -an Alzheimer disease risk factor -although the possession of extra copies of other chromosome 21 genes may also play a part. Further study of the mechanisms underlying the development of Alzheimer disease in people with Down syndrome could provide insights into the mechanisms that cause dementia in the general population.Down syndrome (DS) is a complex, highly variable disorder that arises from trisomy of chromosome 21. It was one of the first chromosomal disorders to be identified 1 and occurs with an incidence of approximately 1 in 800 births 2 . Its prevalence within a given population is influenced by infant mortality rates, access to health care, termination rates, average maternal age 3 and life expectancy. Indeed, despite the increased availability of prenatal diagnosis and access to the option of termination, the global prevalence of DS is rising because of improvements in life expectancy: the number of adults with DS aged over 40 years has doubled in northern Europe since 1990 and, in the United Kingdom, one-third of the estimated 40,000 people with DS are thought to be over 40 years of age 4 .DS is the most common form of intellectual disability. In addition to the features that are found in everyone with the disorder, such as the characteristic facial dysmorphology, there are many DS-associated phenotypes that have variable penetrance and severity. For example, approximately 40% of individuals with DS have heart malformations (usually atrioventricular septal defects) 5 . A key feature of DS is a striking propensity to develop early-onset Alzheimer disease (EOAD). Complete trisomy of chromosome 21 universally causes the development of amyloid plaques and neurofibrillary tangles (NFTs), which are typical characteristics of AD brain pathology, by the age of 40, and approximately twothirds of individuals with DS develop dementia by the age of 60 (REFS 6,7). However, rates of dementia do not reach 100%, even in older individuals, suggesting that some individuals with DS are protected from the onset of AD (FIG. 1).All of the features of DS arise because of aberrant dosages of coding and/or non-coding sequences present on chromosome 21. Among these sequences, the gene encoding amyloid precursor protein (APP) is thought to have a key role in the pathology of AD. The additional copy of APP may drive the development of AD in individuals with DS (AD-DS) by increasing the levels of amyloid-β (Aβ), a cleavage product of APP that misfolds and accumulates in the brain in people with AD. Consistent with this hypothesis, individuals with small internal chromosome 21 duplications that result in three copies of APP -a rare familial trait known as duplic...

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“…Thus, it is also possible that the deficits observed in the current study are not directly correlated with motor learning, and may potentially arise from perceptual or processing deficits. Brain areas involved in biological motion perception, such STS (superior temporal sulcus) and MT (middle temporal) [25,36,37,49,52,53] are frequently mentioned as areas with abnormal structural and functional impairments in DS [13,15,54].…”

Section: Discussionmentioning

confidence: 99%

“…DS is a genetic change that impacts not only intellectual ability, but also motor development and motor control over the lifetime [11,12]. Abnormal brain functioning related to learning has been reveled in a number of studies [13][14][15][16]. In addition to neurodevelopmental abnormalities, corporal abnormalities are also common in DS.…”

mentioning

confidence: 99%

Perception of Biological Motion Speed in Individuals with Down Syndrome

Tolentino-Castro¹,

Riddell²,

Wagner³

2017

J Down Syndr Chr Abnorm

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IntroductionAction and perception are two inherently linked aspects of human behavior that allow us to understand and interact with our surroundings. The interplay between action production and perception enables humans to act in a number of highly demanding situation such as unusual, novel or unstable environments [1]. Babies interact with their environment in a myriad of different ways such as imitation, selfmotion and observing the examples of others [2][3][4]. These interactions serve to shape not only their knowledge about the world, but also their understanding of the functionality of their bodies.Action performance interacts with action perception, and viceversa. This is reflected in the brain, as both performing and perceiving actions activate similar cortical areas [5]. Previous research has revealed significant interactions between action perception and action execution, and studies have shown that action perception can interfere with action execution reciprocally [6][7][8]. It is particularly insightful to study such interactions in populations with abnormal skeleto-muscular and/or neural development, as in these populations the brain may have adapted differently to handle physical differences, which in turn may influence how affected individuals interact with their surroundings. For example Sinha et al. [9] have shown that individuals with autism spectrum disorder, adapt their sensory input atypically, resulting in diverse behavioral traits. Down Syndrome (DS) is one of the most common genetic disorders (14 per 10 000 live births) caused by the presence of a complete or partial third copy of chromosome 21 (Trisomy 21) [10]. DS is a genetic change that impacts not only intellectual ability, but also motor development and motor control over the lifetime [11,12]. Abnormal brain functioning related to learning has been reveled in a number of studies [13][14][15][16]. In addition to neurodevelopmental abnormalities, corporal abnormalities are also common in DS. These abnormalities are highly related to the impaired motor control of voluntary movements [11,17].Children with DS require more time to learn basic movements. Additionally, as movement complexity increases they achieve gross motor functions at an average age that is almost twice that of typically developed children [18]. However, despite delays in motor development and the control of voluntary movements, the DS population does not exhibit a complete absence of the production of gross motor skills. For instance, individuals with DS are often capable of walking and jumping, as well as fine motor skills and manual dexterity. Examples of functional motor development can be seen when special teaching strategies are implemented [19][20][21][22][23][24]. This demonstrates that individuals with DS are at least somewhat able to adapt to their motor impairments. In more realistic tasks, Latash [11,17] argue that, when confronted with an unexpected or unclear motion situation, individuals with DS choose to act slowly (bradykinesia) during the initiation ph...

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Abnormal brain synchrony in Down Syndrome

Cited by 120 publications

References 75 publications

Resting-State Functional Connectivity in Individuals with Down Syndrome and Williams Syndrome Compared with Typically Developing Controls

Resting-State Functional Connectivity in Individuals with Down Syndrome and Williams Syndrome Compared with Typically Developing Controls

A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome

Perception of Biological Motion Speed in Individuals with Down Syndrome

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