Down Syndrome Language Research Papers (original) (raw)

Top Papers
Most Cited Papers
Most Downloaded Papers
Newest Papers
People
- by
- •
- Psychology, Cognitive Psychology, Developmental Psychology, Down Syndrome Language
- by Maria de Fatima de Almeida Baia and +1
- •
- Down Syndrome Language, Language Acquisition and Development, Down Syndrome

Down syndrome (DS) is the most common non-lethal genetic condition that affects approximately 1 in 700 births in the United States of America. DS is characterized by complete or segmental chromosome 21 trisomy, which leads to variable intellectual disabilities, progressive memory loss, and accelerated neurodegeneration with age. During the last three decades, people with DS have experienced a doubling of life expectancy due to progress in treatment of medical comorbidities, which has allowed this population to reach the age when they develop early onset Alzheimer's disease (AD). Individuals with DS develop cognitive and pathological hallmarks of AD in their fourth or fifth decade, and are currently lacking successful prevention or treatment options for dementia. The profound memory deficits associated with DS-related AD (DS-AD) have been associated with degeneration of several neuronal populations, but mechanisms of neurodegeneration are largely unexplored. The most successful animal model for DS is the Ts65Dn mouse, but several new models have also been developed. In the current review, we discuss recent findings and potential treatment options for the management of memory loss and AD neuropathology in DS mouse models. We also review age-related neuropathology, and recent findings from neuroimaging studies. The validation of appropriate DS mouse models that mimic neurodegeneration and memory loss in humans with DS can be valuable in the study of novel preventative and treatment interventions, and may be helpful in pinpointing gene-gene interactions as well as specific gene segments involved in neurodegeneration.

Chromosome 21, triplicated in Down Syndrome, contains several genes that are thought to play a critical role in the development of AD neuropathology. The overexpression of the gene for the amyloid precursor protein (APP), on chromosome 21, leads to early onset beta-amyloid (Aβ) plaques in DS. In addition to Aβ accumulation, middle-aged people with DS develop neurofibrillary tangles, cerebrovascular pathology, white matter pathology, oxidative damage, neuroinflammation and neuron loss. There is also evidence of potential compensatory responses in DS that benefit the brain and delay the onset of dementia after there is sufficient neuropathology for a diagnosis of AD. This review describes some of the existing literature and also highlights gaps in our knowledge regarding AD neuropathology in DS. It will be critical in the future to develop networked brain banks with standardized collection procedures to fully characterize the regional and temporal pathological events associated with aging in DS. As more information is acquired regarding AD evolution in DS, there will be opportunities to develop interventions that are age-appropriate to delay AD in DS.

- by Bentham Science Publishers
- •
- Pathology, Mirror Neurons, Alzheimer's Disease, Down Syndrome Language

Down syndrome is an intellectual disability requiring periodic monitoring of cognition given the near universal presence of Alzheimer’s Disease related neuropathology and high rates of dementia in middle adulthood. We review current approaches to detecting decline in this population, including informant-based measures, dementia screening tools, and neuroimaging techniques. The challenges for detecting decline in this group are discussed, including the need to take into account premorbid cognitive function as well as medical comorbidity.

Locus coeruleus (LC) neurons in the brainstem send extensive noradrenergic (NE)-ergic terminals to the majority of brain regions, particularly those involved in cognitive function. Both Alz-heimer's disease (AD) and Down syndrome (DS) are characterized by similar pathology including significant LC degeneration and dysfunction of the NE-ergic system. Extensive loss of NE-ergic terminals has been linked to alterations in brain regions vital for cognition, mood, and executive function. While the mechanisms by which NE-ergic abnormalities contribute to cognitive dysfunction are not fully understood, emergent evidence suggests that rescue of NE-ergic system can attenuate neuropathology and cogni-tive decline in both AD and DS. Therapeutic strategies to enhance NE neurotransmission have undergone limited testing. Among those deployed to date are NE reuptake inhibitors, presynaptic α-adrenergic receptor antagonists, NE prodrugs, and β-adrenergic agonists. Here we examine alterations in the NE-ergic system in AD and DS and suggest that NE-ergic system rescue is a plausible treatment strategy for targeting cognitive decline in both disorders.

It is well established that individuals with Down syndrome develop Alzheimer's disease neuropathology by middle age. Both in Alzheimer's disease and Down syndrome, this is accompanied by the atrophy of NGF-dependent cholinergic neurons of the basal forebrain. An NGF trophic compromise in Alzheimer's disease had been early suspected. This hypothesis was discarded with the finding of unaltered NGF mRNA synthesis and of increased NGF precursor levels (proNGF) in post-mortem Alzheimer's disease brains. The possibility of an NGF trophic disconnection has been recently revisited at the light of a newly discovered extracellular NGF metabolic pathway; where proNGF is released in an activity-dependent manner and converted by plasmin to mature NGF in the extracellular space. Mature NGF is ultimately degraded by the metalloprotease MMP-9. This pathway has been shown to be compromised in Alzheimer's disease and Down syndrome brains, thus reviving the trophic factor hypothesis to explain the atrophy of basal forebrain cholinergic neurons in these disorders. This chapter will discuss the physiological role of NGF and its biological significance to cho-linergic neurons of the CNS, and present the evidence for a dysregulation of the NGF metabolism in Alzheimer's disease and Down syndrome.

Locus coeruleus (LC) neurons in the brainstem send extensive noradrenergic (NE)-ergic terminals to the majority of brain regions, particularly those involved in cognitive function. Both Alzheimer’s disease (AD) and Down syndrome (DS) are characterized by similar pathology including significant LC degeneration and dysfunction of the NE-ergic system. Extensive loss of NE-ergic terminals has been linked to alterations in brain regions vital for cognition, mood, and executive function. While the mechanisms by which NE-ergic abnormalities contribute to cognitive dysfunction are not fully understood, emergent evidence suggests that rescue of NE-ergic system can attenuate neuropathology and cognitive decline in both AD and DS. Therapeutic strategies to enhance NE neurotransmission have undergone limited testing. Among those deployed to date are NE reuptake inhibitors, presynaptic α-adrenergic receptor antagonists, NE prodrugs, and β-adrenergic agonists. Here we examine alterations in the NE-ergic system in AD and DS and suggest that NE-ergic system rescue is a plausible treatment strategy for targeting cognitive decline in both disorders.

Trisomy 21 and the consequent extra copy of the amyloid precursor protein (APP) gene and increased beta-amyloid (Aβ) peptide production underlie the universal development of Alzheimer’s disease (AD) pathology and high risk of AD dementia in people with Down syndrome (DS). Trisomy 21 and other forms of aneuploidy also arise among neurons and peripheral cells in both sporadic and familial AD and in mouse and cell models thereof, reinforcing the conclusion that AD and DS are two sides of the same coin. The demonstration that 90% of the neurodegeneration in AD can be attributed to the selective loss of aneuploid neurons generated over the course of the disease indicates that aneuploidy is an essential feature of the pathogenic pathway leading to the depletion of neuronal cell populations. Trisomy 21 mosaicism also occurs in neurons and other cells from patients with Niemann-Pick C1 disease and from patients with familial or sporadic frontotemporal lobar degeneration (FTLD), as well as in their corresponding mouse and cell models. Biochemical studies have shown that Aβ induces mitotic spindle defects, chromosome mis-segregation, and aneuploidy in cultured cells by inhibiting specific microtubule motors required for mitosis. These data indicate that neuronal trisomy 21 and other types of aneuploidy characterize and likely contribute to multiple neurodegenerative diseases and are a valid target for therapeutic intervention. For example, reducing extracellular calcium or treating cells with lithium chloride (LiCl) blocks the induction of trisomy 21 by Aβ. The latter finding is relevant in light of recent reports of a lowered risk of dementia in bipolar patients treated with LiCl and in the stabilization of cognition in AD patients treated with LiCl.

Down Syndrome is the most common developmental disorder characterized by mild to moderate intellectual disability. Several studies have reported poor language and prosodic skills, phonological problems due to their deficits caused by intellectual disabilities. This research aims to study over time the expressive use of language in 10 children with Down Syndrome and in 10 children with typical development matched on their chronological age and nonverbal intelligence. We used t tests analyses and the results showed statistically significant development of the oral vocabulary skills in the children with typical development, but not in the children with Down Syndrome, with the typically developing children showing faster and better development in the oral vocabulary skills than the children with Down Syndrome.

- by Dimitra Katsarou
- •
- Down Syndrome Language, Vocabulary Acquisition, Down Syndrome

Down syndrome (DS), caused by trisomy of chromosome 21, is marked by intellectual disability (ID) and early onset of Alzheimer's disease (AD) neuropathology including hippocampal cho-linergic projection system degeneration. Here we determined the effects of age and maternal choline supplementation (MCS) on hippocampal cholinergic deficits in Ts65Dn mice compared to 2N mice sacrificed at 6-8 and 14-18 months of age. Ts65Dn mice and disomic (2N) littermates sacrificed at ages 6-8 and 14-18 mos were used for an aging study and Ts65Dn and 2N mice derived from Ts65Dn dams were maintained on either a choline-supplemented or a choline-controlled diet (conception to weaning) and examined at 14-18 mos for MCS studies. In the latter, mice were be-haviorally tested on the radial arm Morris water maze (RAWM) and hippocampal tissue was examined for intensity of choline acetyltransferase (ChAT) immunoreactivity. Hippocampal ChAT activity was evaluated in a separate cohort. ChAT-positive fiber innervation was significantly higher in the hippocampus and dentate gyrus in Ts65Dn mice compared with 2N mice, independent of age or maternal diet. Similarly, hippocampal ChAT activity was significantly elevated in Ts65Dn mice compared to 2N mice, independent of maternal diet. A significant increase with age was seen in hippocam-pal cholinergic innervation of 2N mice, but not Ts65Dn mice. Degree of ChAT intensity correlated negatively with spatial memory ability in unsupplemented 2N and Ts65Dn mice, but positively in MCS 2N mice. The increased innervation produced by MCS appears to improve hippocampal function, making this a therapy that may be exploited for future transla-tional approaches in human DS.

- by Bentham Science Publishers
- •
- Alzheimer's Disease, Spatial Memory, Down Syndrome Language, Aging

Trisomy 21 and the consequent extra copy of the amyloid precursor protein (APP) gene and increased beta-amyloid (Aβ) peptide production underlie the universal development of Alzheimer's disease (AD) pathology and high risk of AD dementia in people with Down syndrome (DS). Trisomy 21 and other forms of aneuploidy also arise among neurons and peripheral cells in both sporadic and familial AD and in mouse and cell models thereof, reinforcing the conclusion that AD and DS are two sides of the same coin. The demonstration that 90% of the neurodegeneration in AD can be attributed to the selective loss of aneuploid neurons generated over the course of the disease indicates that aneuploidy is an essential feature of the pathogenic pathway leading to the depletion of neuronal cell populations. Trisomy 21 mosaicism also occurs in neurons and other cells from patients with Niemann-Pick C1 disease and from patients with familial or sporadic frontotemporal lobar degeneration (FTLD), as well as in their corresponding mouse and cell models. Biochemical studies have shown that Aβ induces mitotic spindle defects, chromosome mis-segregation, and aneuploidy in cultured cells by inhibiting specific microtubule motors required for mitosis. These data indicate that neuronal trisomy 21 and other types of aneuploidy characterize and likely contribute to multiple neurodegenerative diseases and are a valid target for therapeutic intervention. For example, reducing extracellular calcium or treating cells with lithium chloride (LiCl) blocks the induction of trisomy 21 by Aβ. The latter finding is relevant in light of recent reports of a lowered risk of dementia in bipolar patients treated with LiCl and in the stabilization of cognition in AD patients treated with LiCl.

Down syndrome (DS) is a special biogenetic complexity that induces many deficiencies which lead to developmental issues such as difficulty in encoding information and low awareness to interpret them for decision making. This causes down syndrome children to move away from society as they feel hard with communicating and dealing. As a better method of communication for down syndrome children, free-hand sketch drawings can be effectively used. The teachers and consultants identified this way as the best way to generalize such children’s mind working patterns and expressing ideas. Considering the availability of touchscreen devices, it has made freehand sketch drawing a more friendly activity than in the past. Since in this project, the hand-drawn sketches that are created through touchscreen devices were adopted. Due to the novel development of machine learning and its progress, the freehand sketch drawing related research and applications are moving at a massive progress rate. The main aim of this project is to develop a reliable and efficient approach to predict down syndrome children drawings through model structure building for those hand-drawn sketches plus classify and recognize those sketches compared to the teacher. To the best of our knowledge, this is the first work that proposes this kind of approach for down syndrome children drawings. During the development process, mainly Tensorflow, Python, OpenCV, Keras, KNN and Matplotlib were adopted. This research-based project specially considered local down syndrome children in grade three (age 8–10). This real-time approach takes drawings as the input. Then it processes model structure building of new sketches for prediction and then begins the prediction process through the classification of sketches and recognition. As a result, it gives a comparison with the teacher's drawing and corresponding components in the down syndrome child's drawing. Through that, the drawing ability of the down syndrome children and their communicated expression of those drawings can be appraised for further comparisons and analysis.

- by Gayasha Malluwawadu
- •
- Artificial Intelligence, Communication, Special Education, Image Processing

Chromosome 21, triplicated in Down Syndrome, contains several genes that are thought to play a critical role in the development of AD neuropathology. The overexpression of the gene for the amyloid precursor protein (APP), on chromosome 21, leads to early onset beta-amyloid (Aβ) plaques in DS. In addition to Aβ accumulation, middle-aged people with DS develop neurofibrillary tangles, cerebrovascular pathology , white matter pathology, oxidative damage, neuroinflammation and neuron loss. There is also evidence of potential compensatory responses in DS that benefit the brain and delay the onset of dementia after there is sufficient neuropa-thology for a diagnosis of AD. This review describes some of the existing literature and also highlights gaps in our knowledge regarding AD neuropathology in DS. It will be critical in the future to develop networked brain banks with standardized collection procedures to fully characterize the regional and temporal pathological events associated with aging in DS. As more information is acquired regarding AD evolution in DS, there will be opportunities to develop interventions that are age-appropriate to delay AD in DS.

It is well established that individuals with Down syndrome develop Alzheimer’s disease neuropathology by middle age. Both in Alzheimer’s disease and Down syndrome, this is accompanied by the atrophy of NGF-dependent cholinergic neurons of the basal forebrain. An NGF trophic compromise in Alzheimer’s disease had been early suspected. This hypothesis was discarded with the finding of unaltered NGF mRNA synthesis and of increased NGF precursor levels (proNGF) in postmortem Alzheimer’s disease brains. The possibility of an NGF trophic disconnection has been recently revisited at the light of a newly discovered extracellular NGF metabolic pathway; where proNGF is released in an activity-dependent manner and converted by plasmin to mature NGF in the extracellular space. Mature NGF is ultimately degraded by the metalloprotease MMP-9. This pathway has been shown to be compromised in Alzheimer’s disease and Down syndrome brains, thus reviving the trophic factor hypothesis to explain the atrophy of basal forebrain cholinergic neurons in these disorders. This chapter will discuss the physiological role of NGF and its biological significance to cholinergic neurons of the CNS, and present the evidence for a dysregulation of the NGF metabolism in Alzheimer’s disease and Down syndrome.

This research focuses on language processing, and more specifically on semantic processing, in children with Down Syndrome (DS). It has repeatedly been documented that children with DS display severe deficits in all language domains, semantics among others, and especially in their expressive language. Therefore, our purpose was to detect possible differences between receptive and expressive language in the semantic domain in DS and to compare semantic processing, both receptive and expressive, of children with DS with that of children with typical development. For this purpose we examined two groups of children, a group of children with Down Syndrome (DS) and a group of children with typical development (TD), aged 4-7.11 years old. Our findings proved that children with DS scored lower than typically developing children in all semantic tasks, whether receptive or expressive and that their performance was lower in the expressive language tasks than the receptive ones.

- by Dimitra Katsarou
- •
- Cognitive Psychology, Cognitive Science, Developmental Psychology, Semantics

- by Dimitra Katsarou
- •
- Semantics, Down Syndrome Language, Down Syndrome

Down syndrome is the most common known cause of intellectual disability and occurs in approximately 1 in 700 births. Language skills of children with DS are more severely affected than their nonverbal cognition. Expressive language skills are poorer than receptive ones, especially syntax which tends to be considerably delayed. Moreover, children with DS tend to make more grammatical errors than typically developing children. The purpose of this study is to examine whether morphosyntactic abilities of children with DS are poorer than the abilities of typically developing children, taking into consideration that research is extremely poor in this area and especially in the Greek language. For this purpose, 10 children with DS and 10 typically developing children have been examined in a 45 minute morphosyntactic abilities task. Our findings are in line with previous research, proving that expressive and receptive syntax is delayed and severely affected in children with DS.

Children with Down syndrome (DS) present language deficits in all linguistic domains and their language development lags behind that of typically developing children. However, their receptive language skills appear to be better than their productive in all linguistic domains. Research on bilingual children with DS is limited, but has shown that second language learning from an early age by children with DS has no impact on their first language development. In this research study, we examined receptive and productive first language skills of eight monolingual and eight bilingual children with DS. For the above purpose, a standardised language test, that measures the receptive and expressive language system, was administered to all participants. The results of our study showed that bilingual children with DS do not differ in their receptive and productive language skills from monolingual children with DS, indicating that bilingualism does not affect first language development in DS.

- by Dimitra Katsarou
- •
- Down Syndrome Language, Bilingualism, Preschool Education

Trisomy 21 and the consequent extra copy of the amyloid precursor protein (APP) gene and increased beta-amyloid (Aβ) peptide production underlie the universal development of Alzheimer's disease (AD) pathology and high risk of AD dementia in people with Down syndrome (DS). Trisomy 21 and other forms of aneuploidy also arise among neurons and peripheral cells in both sporadic and familial AD and in mouse and cell models thereof, reinforcing the conclusion that AD and DS are two sides of the same coin. The demonstration that 90% of the neurodegeneration in AD can be attributed to the selective loss of aneuploid neurons generated over the course of the disease indicates that aneuploidy is an essential feature of the pathogenic pathway leading to the depletion of neuronal cell populations. Trisomy 21 mosaicism also occurs in neurons and other cells from patients with Niemann-Pick C1 disease and from patients with familial or sporadic frontotemporal lobar degeneration (FTLD), as well as in their corresponding mouse and cell models. Biochemical studies have shown that Aβ induces mitotic spindle defects, chromosome mis-segregation, and aneuploidy in cultured cells by inhibiting specific microtubule motors required for mitosis. These data indicate that neuronal trisomy 21 and other types of aneuploidy characterize and likely contribute to multiple neurodegenerative diseases and are a valid target for therapeutic intervention. For example, reducing extracellular calcium or treating cells with lithium chloride (LiCl) blocks the induction of trisomy 21 by Aβ. The latter finding is relevant in light of recent reports of a lowered risk of dementia in bipolar patients treated with LiCl and in the stabilization of cognition in AD patients treated with LiCl.

- by Huntington Potter
- •
- Neurogenesis, Down Syndrome Language, Adult neurogenesis, Cell Cycle