scholarly journals Low striatal T3 is implicated in inattention and memory impairment in an ADHD mouse model overexpressing thyroid hormone-responsive protein

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Raly James Perez Custodio ◽  
Mikyung Kim ◽  
Leandro Val Sayson ◽  
Hyun Jun Lee ◽  
Darlene Mae Ortiz ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Memory Impairment ◽  
Neurodevelopmental Disorder ◽  
Monocarboxylate Transporter ◽  
Male Mice ◽  
Pathogenetic Mechanism ◽  
Physiological Characterization ◽  
Hyperactivity Disorder ◽  
Theta Waves ◽  
Transgenic Mouse Strain

AbstractAttention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder, potentially with a biological basis; however, its exact cause remains unknown. Thyroid hormone (TH) abnormalities are more prevalent in patients with ADHD than in the general population, indicating a shared pathogenetic mechanism for these conditions. Previously, we identified that overexpression of thyroid hormone-responsive protein (THRSP), a gene highly responsive to TH status, induced inattention in male mice. Herein, we sought to explore whether TH function in THRSP-overexpressing (THRSP OE) mice influences ADHD-like (inattention) behavior. We now confirm that THRSP overexpression in male mice reproduces behavioral features of ADHD, including sustained inattention and memory impairment, accompanied by excessive theta waves that were found normal in both the THRSP-knockout and hetero groups. Physiological characterization revealed low striatal T3 levels in the THRSP OE mice due to reduced striatal T3-specific monocarboxylate transporter 8 (MCT8), indicating brain-specific hypothyroidism in this transgenic mouse strain. TH replacement for seven days rescued inattention and memory impairment and the normalization of theta waves. This study further supports the involvement of the upregulated THRSP gene in ADHD pathology and indicates that THRSP OE mice can serve as an animal model for the predominantly inattentive subtype of ADHD.

scholarly journals Importance of Monocarboxylate Transporter 8 for the Blood-Brain Barrier-Dependent Availability of 3,5,3′-Triiodo-l-Thyronine

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2491-2496 ◽  
Author(s):  
Ainhoa Ceballos ◽  
Monica M. Belinchon ◽  
Eduardo Sanchez-Mendoza ◽  
Carmen Grijota-Martinez ◽  
Alexandra M. Dumitrescu ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Blood Brain Barrier ◽  
Neurodevelopmental Disorder ◽  
Genetically Engineered ◽  
Brain Barrier ◽  
Monocarboxylate Transporter ◽  
Target Cells ◽  
Relative Role ◽  
Restricted Access ◽  
Blood Brain

Mutations of the gene expressing plasma membrane transporter for thyroid hormones MCT8 (SLC16A2) in humans lead to altered thyroid hormone levels and a severe neurodevelopmental disorder. Genetically engineered defect of the Mct8 gene in mice leads to similar thyroid hormone abnormalities but no obvious impairment of brain development or function. In this work we studied the relative role of the blood-brain barrier and the neuronal plasma cell membrane in the restricted access of T3 to the target neurons. To this end we compared the effects of low doses of T4 and T3 on cerebellar structure and gene expression in wild-type (Wt) and Mct8 null male mice [Mct8-/y, knockout (KO)] made hypothyroid during the neonatal period. We found that compared with Wt animals, T4 was considerably more potent than T3 in the Mct8KO mice, indicating a restricted access of T3, but not T4, to neurons after systemic administration in vivo. In contrast, T3 action in cultured cerebellar neurons was similar in Wt cells as in Mct8KO cells. The results suggest that the main restriction for T3 entry into the neural target cells of the mouse deficient in Mct8 is at the blood-brain barrier.

scholarly journals A Cross-Sectional Study of 0.6 Million Children with Attention-Deficit/Hyperactivity Disorder in the United States

2020 ◽  
Vol 10 (01) ◽  
pp. e97-e103
Author(s):  
Irene Rethemiotaki
Keyword(s):  
United States ◽  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Family Income ◽  
Neurodevelopmental Disorder ◽  
Multiple Logistic Regression Analysis ◽  
The United States ◽  
Cross Sectional ◽  
Children With Adhd ◽  
Hyperactivity Disorder

AbstractAttention-deficit hyperactivity disorder (ADHD) is an increasingly recognized chronic neurodevelopmental disorder. This work aims at studying the prevalence and clinical characteristics of children with ADHD in the United States in the period between 2009 and 2018. Data from the National Health Interview Survey were analyzed by univariate and multivariate statistics to assess the role of socioeconomic factors in the development of ADHD. It has been studied 615,608 children, 51.2% male and 48.7% female. The prevalence of ADHD was 9.13%, with males predominating over females. The number of children with ADHD increased from 2009 to 2018 by 14.8%. As specified by multiple logistic regression analysis, males (odds ratio [OR] 2.38) who have neither mother nor father (OR 1.76) are twice as likely to have ADHD compared with their peers. In addition, family income (OR 1.40) and parent's education (OR 1.12) were significantly associated with ADHD. It has been highlighted the significance of deprivation of both family and financial comfort as primary indicators for ADHD in children. Moreover, children with ADHD were more likely to be males in the age group of 12 to 17.

scholarly journals Altered dopaminergic firing pattern and novelty response underlie ADHD-like behavior of SorCS2-deficient mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ditte Olsen ◽  
Niels Wellner ◽  
Mathias Kaas ◽  
Inge E. M. de Jong ◽  
Florence Sotty ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
Firing Pattern ◽  
Neurodevelopmental Disorder ◽  
Paradoxical Response ◽  
Dopaminergic Transmission ◽  
Hyperactivity Disorder ◽  
Responses To Dopamine ◽  
Circuit Function ◽  
Underlying Pathophysiology

AbstractAttention deficit hyperactivity disorder (ADHD) is the most frequently diagnosed neurodevelopmental disorder worldwide. Affected individuals present with hyperactivity, inattention, and cognitive deficits and display a characteristic paradoxical response to drugs affecting the dopaminergic system. However, the underlying pathophysiology of ADHD and how this relates to dopaminergic transmission remains to be fully understood. Sorcs2−/− mice uniquely recapitulate symptoms reminiscent of ADHD in humans. Here, we show that lack of SorCS2 in mice results in lower sucrose intake, indicating general reward deficits. Using in-vivo recordings, we further find that dopaminergic transmission in the ventral tegmental area (VTA) is shifted towards a more regular firing pattern with marked reductions in the relative occurrence of irregular firing in Sorcs2−/− mice. This was paralleled by abnormal acute behavioral responses to dopamine receptor agonists, suggesting fundamental differences in dopaminergic circuits and indicating a perturbation in the balance between the activities of the postsynaptic dopamine receptor DRD1 and the presynaptic inhibitory autoreceptor DRD2. Interestingly, the hyperactivity and drug response of Sorcs2−/− mice were markedly affected by novelty. Taken together, our findings show how loss of a candidate ADHD-risk gene has marked effects on dopaminergic circuit function and the behavioral response to the environment.

scholarly journals DNA Methylation in LIME1 and SPTBN2 Genes Is Associated with Attention Deficit in Children

Children ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 92
Author(s):  
Sung-Chou Li ◽  
Ho-Chang Kuo ◽  
Lien-Hung Huang ◽  
Wen-Jiun Chou ◽  
Sheng-Yu Lee ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Attention Deficit ◽  
Performance Test ◽  
Neurodevelopmental Disorder ◽  
Continuous Performance Test ◽  
Attention Deficits ◽  
Clinical Settings ◽  
Hyperactivity Disorder ◽  
Cpg Sites ◽  
Healthy Control

DNA methylation levels are associated with neurodevelopment. Attention-deficit/hyperactivity disorder (ADHD), characterized by attention deficits, is a common neurodevelopmental disorder. We used methylation microarray and pyrosequencing to detect peripheral blood DNA methylation markers of ADHD. DNA methylation profiling data from the microarray assays identified potential differentially methylated CpG sites between 12 ADHD patients and 9 controls. Five candidate CpG sites (cg00446123, cg20513976, cg07922513, cg17096979, and cg02506324) in four genes (LIME1, KCNAB2, CAPN9, and SPTBN2) were further examined with pyrosequencing. The attention of patients were tested using the Conners’ Continuous Performance Test (CPT). In total, 126 ADHD patients with a mean age of 9.2 years (78.6% males) and 72 healthy control subjects with a mean age of 9.3 years (62.5% males) were recruited. When all participants were categorized by their CPT performance, the DNA methylation levels in LIME1 (cg00446123 and cg20513976) were found to be significantly higher and those in SPTBN2 (cg02506324) were significantly lower in children with worse CPT performance. Therefore, DNA methylation of two CpG sites in LIME1 and one CpG site in SPTBN2 is associated with attention deficits in children. DNA methylation biomarkers may assist in identifying attention deficits of children in clinical settings.

scholarly journals Elevated Expression of SLC6A4 Encoding the Serotonin Transporter (SERT) in Gilles de la Tourette Syndrome

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 86
Author(s):  
Mathis Hildonen ◽  
Amanda M. Levy ◽  
Christina Dahl ◽  
Victoria A. Bjerregaard ◽  
Lisbeth Birk Møller ◽  
...  
Keyword(s):  
Tourette Syndrome ◽  
Serotonin Transporter ◽  
Neurodevelopmental Disorder ◽  
Control Group ◽  
Obsessive Compulsive ◽  
Expression Levels ◽  
Compulsive Disorder ◽  
Hyperactivity Disorder ◽  
Elevated Expression ◽  
Gene Expression Levels

Gilles de la Tourette syndrome (GTS) is a complex neurodevelopmental disorder characterized by motor and vocal tics. Most of the GTS individuals have comorbid diagnoses, of which obsessive-compulsive disorder (OCD) and attention deficit-hyperactivity disorder (ADHD) are the most common. Several neurotransmitter systems have been implicated in disease pathogenesis, and amongst these, the dopaminergic and the serotonergic pathways are the most widely studied. In this study, we aimed to investigate whether the serotonin transporter (SERT) gene (SLC6A4) was differentially expressed among GTS individuals compared to healthy controls, and whether DNA variants (the SERT-linked polymorphic region 5-HTTLPR, together with the associated rs25531 and rs25532 variants, and the rare Ile425Val variant) or promoter methylation of SLC6A4 were associated with gene expression levels or with the presence of OCD as comorbidity. We observed that SLC6A4 expression is upregulated in GTS individuals compared to controls. Although no specific genotype, allele or haplotype was overrepresented in GTS individuals compared to controls, we observed that the LAC/LAC genotype of the 5-HTTLPR/rs25531/rs25532 three-locus haplotype was associated with higher SLC6A4 mRNA expression levels in GTS individuals, but not in the control group.

scholarly journals Minireview: Thyroid Hormone Transporters: The Knowns and the Unknowns

2011 ◽  
Vol 25 (1) ◽  
pp. 1-14 ◽  
Author(s):  
W. Edward Visser ◽  
Edith C. H. Friesema ◽  
Theo J. Visser
Keyword(s):  
Thyroid Hormone ◽  
Organic Anion ◽  
Psychomotor Retardation ◽  
Cellular Level ◽  
Monocarboxylate Transporter ◽  
Causative Role ◽  
Organic Anion Transporting Polypeptide ◽  
Neurological Abnormalities ◽  
Knockout Animals

The effects of thyroid hormone (TH) on development and metabolism are exerted at the cellular level. Metabolism and action of TH take place intracellularly, which require transport of the hormone across the plasma membrane. This process is mediated by TH transporter proteins. Many TH transporters have been identified at the molecular level, although a few are classified as specific TH transporters, including monocarboxylate transporter (MCT)8, MCT10, and organic anion-transporting polypeptide 1C1. The importance of TH transporters for physiology has been illustrated dramatically by the causative role of MCT8 mutations in males with psychomotor retardation and abnormal serum TH concentrations. Although Mct8 knockout animals have provided insight in the mechanisms underlying parts of the endocrine phenotype, they lack obvious neurological abnormalities. Thus, the pathogenesis of the neurological abnormalities in males with MCT8 mutations is not fully understood. The prospects of identifying other transporters and transporter-based syndromes promise an exciting future in the TH transporter field.

scholarly journals Positive Child Personality Factors in Children with ADHD

2021 ◽  
pp. 108705472199756
Author(s):  
Tasmia Hai ◽  
Emma A. Climie
Keyword(s):  
Social Skills ◽  
Neurodevelopmental Disorder ◽  
Personality Factors ◽  
Substantial Impact ◽  
Children With Adhd ◽  
Hyperactivity Disorder ◽  
Behavioral Competence ◽  
Strength Based ◽  
And Coping ◽  
Multiple Domains

Objective: Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder. While previous studies have shown substantial impact of ADHD across multiple domains, relatively little attention has been devoted to studying positive personality factors in individuals with ADHD. To address this, the current study examined strength-based factors in children with ADHD in relation to their social skills. Method: Sixty-four children (aged 8–12 years) with ADHD completed questionnaires related to their social skills and strength-based factors (e.g., optimism, resilience, self-concept, and coping skills). Results: Findings indicated significant differences between different levels of social skills in children with ADHD, with children with higher social skills reporting higher levels of resiliency, greater behavioral competence, and greater prosocial attitudes than those with lower social skills. Conclusions: The results highlight the importance of fostering strong social skills in children with ADHD, leading them to perceive themselves as competent and resilient.

scholarly journals SHR/NCrl rats as a model of ADHD can be discriminated from controls based on their brain, blood, or urine metabolomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Camille Dupuy ◽  
Pierre Castelnau ◽  
Sylvie Mavel ◽  
Antoine Lefevre ◽  
Lydie Nadal-Desbarats ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Attention Deficit Hyperactivity Disorder ◽  
Animal Model ◽  
Metabolic Pathways ◽  
Neurodevelopmental Disorder ◽  
Hyperactivity Disorder ◽  
Pathophysiological Condition ◽  
The Brain ◽  
And Oxidative Stress ◽  
Peripheral Samples

AbstractAttention-Deficit Hyperactivity Disorder (ADHD) is one of the most common neurodevelopmental disorder characterized by inattention, impulsivity, and hyperactivity. The neurobiological mechanisms underlying ADHD are still poorly understood, and its diagnosis remains difficult due to its heterogeneity. Metabolomics is a recent strategy for the holistic exploration of metabolism and is well suited for investigating the pathophysiology of diseases and finding molecular biomarkers. A few clinical metabolomic studies have been performed on peripheral samples from ADHD patients but are limited by their access to the brain. Here, we investigated the brain, blood, and urine metabolomes of SHR/NCrl vs WKY/NHsd rats to better understand the neurobiology and to find potential peripheral biomarkers underlying the ADHD-like phenotype of this animal model. We showed that SHR/NCrl rats can be differentiated from controls based on their brain, blood, and urine metabolomes. In the brain, SHR/NCrl rats displayed modifications in metabolic pathways related to energy metabolism and oxidative stress further supporting their importance in the pathophysiology of ADHD bringing news arguments in favor of the Neuroenergetic theory of ADHD. Besides, the peripheral metabolome of SHR/NCrl rats also shared more than half of these differences further supporting the importance of looking at multiple matrices to characterize a pathophysiological condition of an individual. This also stresses out the importance of investigating the peripheral energy and oxidative stress metabolic pathways in the search of biomarkers of ADHD.

scholarly journals Sex-dependent role for EPHB2 in brain development and autism-associated behavior

2021 ◽  
Author(s):  
Ahlem Assali ◽  
Jennifer Y. Cho ◽  
Evgeny Tsvetkov ◽  
Abha R. Gupta ◽  
Christopher W. Cowan
Keyword(s):  
Pyramidal Neurons ◽  
De Novo ◽  
Repetitive Behavior ◽  
Autism Spectrum ◽  
Repetitive Behaviors ◽  
Male Mice ◽  
Sensory Sensitivity ◽  
Hyperactivity Disorder ◽  
Specific Effects ◽  
Layer V

AbstractAutism spectrum disorder (ASD) is characterized by impairments in social communication and interaction and restricted, repetitive behaviors. It is frequently associated with comorbidities, such as attention-deficit hyperactivity disorder, altered sensory sensitivity, and intellectual disability. A de novo nonsense mutation in EPHB2 (Q857X) was discovered in a female patient with ASD [13], revealing EPHB2 as a candidate ASD risk gene. EPHB2 is a receptor tyrosine kinase implicated in axon guidance, synaptogenesis, and synaptic plasticity, positioning it as a plausible contributor to the pathophysiology of ASD and related disorders. In this study, we show that the Q857X mutation produced a truncated protein lacking forward signaling and that global disruption of one EphB2 allele (EphB2+/−) in mice produced several behavioral phenotypes reminiscent of ASD and common associated symptoms. EphB2+/− female, but not male, mice displayed increased repetitive behavior, motor hyperactivity, and learning and memory deficits, revealing sex-specific effects of EPHB2 hypofunction. Moreover, we observed a significant increase in the intrinsic excitability, but not excitatory/inhibitory ratio, of motor cortex layer V pyramidal neurons in EphB2+/− female, but not male, mice, suggesting a possible mechanism by which EPHB2 hypofunction may contribute to sex-specific motor-related phenotypes. Together, our findings suggest that EPHB2 hypofunction, particularly in females, is sufficient to produce ASD-associated behaviors and altered cortical functions in mice.

Age-related changes in renal and hepatic cellular mechanisms associated with variations in rat serum thyroid hormone levels

2008 ◽  
Vol 294 (6) ◽  
pp. E1160-E1168 ◽  
Author(s):  
Elena Silvestri ◽  
Assunta Lombardi ◽  
Pieter de Lange ◽  
Luigi Schiavo ◽  
Antonia Lanni ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Total Protein ◽  
Protein Level ◽  
Monocarboxylate Transporter ◽  
Type I ◽  
Peripheral Tissues ◽  
Protein Levels ◽  
Age Related ◽  
Liver And Kidney ◽  
Age Related Changes

Aging is associated with changes in thyroid gland physiology. Age-related changes in the contribution of peripheral tissues to thyroid hormone serum levels have yet to be systematically assessed. Here, we investigated age-related alterations in the contributions of the liver and kidney to thyroid hormone homeostasis using 6-, 12-, and 24-mo-old male Wistar rats. A significant and progressive decline in plasma thyroxine occurred with age, but triiodothyronine (T3) was decreased only at 24 mo. This was associated with an unchanged protein level of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) in the kidney and with a decreased MCT8 level in the liver at 24 mo. Hepatic type I deiodinase (D1) protein level and activity declined progressively with age. Renal D1 levels were decreased at both 12 and 24 mo but D1 activity was decreased only at 24 mo. In the liver, no changes occurred in thyroid hormone receptor (TR) TRα1, whereas a progressive increase in TRβ1 occurred at both mRNA and total protein levels. In the kidney, both TRα1 and TRβ1 mRNA and total protein levels were unchanged between 6 and 12 mo but increased at 24 mo. Interestingly, nuclear TRβ1 levels were decreased in both liver and kidney at 12 and 24 mo, whereas nuclear TRα1 levels were unchanged. Collectively, our data show differential age-related changes among hepatic and renal MCT8 and D1 and TR expressions, and they suggest that renal D1 activity is maintained with age to compensate for the decrease in hepatic T3 production.

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