scholarly journals Inhibiting proBDNF to mature BDNF conversion leads to autism-like phenotypes in vivo

2020 ◽  
Author(s):  
He You ◽  
Toshiyuki Mizui ◽  
Kazuyuki Kiyosue ◽  
Keizo Takao ◽  
Tsuyoshi Miyakawa ◽  
...  
Keyword(s):  
Autism Spectrum ◽  
Synaptic Function ◽  
Early Age ◽  
Mouse Line ◽  
Brain Volumes ◽  
Blood Marker ◽  
Spectrum Disorders ◽  
Neurodevelopment Disorders ◽  
The Brain

AbstractAutism spectrum disorders (ASD) comprise a range of early age-onset neurodevelopment disorders with genetic heterogeneity. Most ASD related genes are involved in synaptic function, which is oppositely regulated by brain-derived neurotrophic factor (BDNF): the precursor proBDNF inhibits while mature BDNF (mBDNF) potentiates synapses. Here we generated a knock-in mouse line (BDNFmet/leu) in which the conversion of proBDNF to mBDNF is inhibited. Biochemical experiments revealed residual mBDNF but excessive proBDNF in the brain. Similar to other ASD mouse models, the BDNFmet/leu mice showed decreased brain volumes, reduced dendritic arborization, altered spines, and impaired synaptic transmission and plasticity. They also exhibited ASD-like phenotypes, including stereotypical behaviors, deficits in social interaction, hyperactivity, and elevated stress response. Interestingly, the plasma level of proBDNF, but not mBDNF, was significantly elevated in ASD patients. These results suggest that proBDNF level, but not Bdnf gene, is associated with autism-spectrum behaviors, and identify a potential blood marker and therapeutic target for ASD.

scholarly journals Induction of core symptoms of autism spectrum disorders by in vivo CRISPR/Cas9-based gene editing in the brain of adolescent rhesus monkeys

2020 ◽  
Author(s):  
Shi-Hao Wu ◽  
Xiao Li ◽  
Dong-Dong Qin ◽  
Lin-Heng Zhang ◽  
Tian-Lin Cheng ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Rhesus Monkeys ◽  
Gene Editing ◽  
Autism Spectrum ◽  
Genetically Engineered ◽  
Behavioral Abnormalities ◽  
Spectrum Disorders ◽  
Rapid Generation ◽  
The Brain

AbstractAlthough CRISPR/Cas9-mediated gene editing is widely applied to mimic human disorders, whether acute manipulation of disease-causing genes in the brain leads to behavioral abnormalities in non-human primates remains to be determined. Here we induced genetic mutations in MECP2, a critical gene linked to Rett syndrome (RTT) and autism spectrum disorders (ASDs), in the hippocampus (DG and CA1–4) of adolescent rhesus monkeys (Macaca mulatta) in vivo via adeno-associated virus (AAV)-delivered Staphylococcus aureus Cas9 with sgRNAs targeting MECP2. In comparison to monkeys injected with AAV-SaCas9 alone (n = 4), numerous autistic-like behavioral abnormalities were identified in the AAV-SaCas9-sgMECP2-injected monkeys (n = 7), including social interaction deficits, abnormal sleep patterns, insensitivity to aversive stimuli, abnormal hand motions and defective social reward behaviors. Furthermore, some aspects of ASDs and RTT, such as stereotypic behaviors, did not appear in the MECP2 gene-edited monkeys, suggesting that different brain areas likely contribute to distinct ASD symptoms. This study showed that acute manipulation of disease-causing genes via in vivo gene editing directly led to behavioral changes in adolescent primates, paving the way for the rapid generation of genetically engineered non-human primate models for neurobiological studies and therapeutic development.

scholarly journals Region-specific elevations of glutamate + glutamine correlate with the sensory symptoms of autism spectrum disorders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jason L. He ◽  
Georg Oeltzschner ◽  
Mark Mikkelsen ◽  
Alyssa Deronda ◽  
Ashley D. Harris ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Strong Support ◽  
Empirical Support ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Resonance Spectroscopy ◽  
Primary Sensorimotor Cortex ◽  
Spectrum Disorders ◽  
Inhibitory Signaling

AbstractIndividuals on the autism spectrum are often reported as being hyper- and/or hyporeactive to sensory input. These sensory symptoms were one of the key observations that led to the development of the altered excitation-inhibition (E-I) model of autism, which posits that an increase ratio of excitatory to inhibitory signaling may explain certain phenotypical expressions of autism spectrum disorders (ASD). While there has been strong support for the altered E-I model of autism, much of the evidence has come from animal models. With regard to in-vivo human studies, evidence for altered E-I balance in ASD come from studies adopting magnetic resonance spectroscopy (MRS). Spectral-edited MRS can be used to provide measures of the levels of GABA + (GABA + macromolecules) and Glx (glutamate + glutamine) in specific brain regions as proxy markers of inhibition and excitation respectively. In the current study, we found region-specific elevations of Glx in the primary sensorimotor cortex (SM1) in ASD. There were no group differences of GABA+ in either the SM1 or thalamus. Higher levels of Glx were associated with more parent reported difficulties of sensory hyper- and hyporeactivity, as well as reduced feed-forward inhibition during tactile perception in children with ASD. Critically, the finding of elevated Glx provides strong empirical support for increased excitation in ASD. Our results also provide a clear link between Glx and the sensory symptoms of ASD at both behavioral and perceptual levels.

scholarly journals Genetic Approaches Using Zebrafish to Study the Microbiota–Gut–Brain Axis in Neurological Disorders

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 566
Author(s):  
Jae-Geun Lee ◽  
Hyun-Ju Cho ◽  
Yun-Mi Jeong ◽  
Jeong-Soo Lee
Keyword(s):  
Neurological Disorders ◽  
Genetic Model ◽  
Molecular Genetic ◽  
Autism Spectrum ◽  
Behavioral Abnormalities ◽  
Bidirectional Signaling ◽  
Intestinal Dysbiosis ◽  
The Central Nervous System ◽  
The Brain

The microbiota–gut–brain axis (MGBA) is a bidirectional signaling pathway mediating the interaction of the microbiota, the intestine, and the central nervous system. While the MGBA plays a pivotal role in normal development and physiology of the nervous and gastrointestinal system of the host, its dysfunction has been strongly implicated in neurological disorders, where intestinal dysbiosis and derived metabolites cause barrier permeability defects and elicit local inflammation of the gastrointestinal tract, concomitant with increased pro-inflammatory cytokines, mobilization and infiltration of immune cells into the brain, and the dysregulated activation of the vagus nerve, culminating in neuroinflammation and neuronal dysfunction of the brain and behavioral abnormalities. In this topical review, we summarize recent findings in human and animal models regarding the roles of the MGBA in physiological and neuropathological conditions, and discuss the molecular, genetic, and neurobehavioral characteristics of zebrafish as an animal model to study the MGBA. The exploitation of zebrafish as an amenable genetic model combined with in vivo imaging capabilities and gnotobiotic approaches at the whole organism level may reveal novel mechanistic insights into microbiota–gut–brain interactions, especially in the context of neurological disorders such as autism spectrum disorder and Alzheimer’s disease.

Differentiation of Healthy Individuals from Those with Autism Spectrum Disorders using Information Graph of Complementary Opposites

2020 ◽  
Keyword(s):  
Children With Autism ◽  
Autism Spectrum ◽  
Brain Signals ◽  
Three Stages ◽  
The Mean ◽  
Spectrum Disorders ◽  
Pediatric Psychiatry ◽  
The Brain ◽  
Optimal Feature ◽  
Information Graph

This study aimed to examine the brain signals of children with Autism Spectrum Disorder (ASD) and use a method according to the concept of complementary opposites to obtain the prominent features or a pattern of EEG signal that represents the biological characteristic of such children. In this study, 20 children with the mean±SD age of 8±5 years were divided into two groups of normal control (NC) and ASD. The diagnosis and approval of individuals in both groups were conducted by two experts in the field of pediatric psychiatry and neurology. The recording protocol was designed with the most accuracy; therefore, the brain signals were recorded with the least noise in the awake state of the individuals in both groups. Moreover, the recording was conducted in three stages from two channels (C3-C4) of EEG ( referred to as the central part of the brain) which were symmetrical in function. In this study, the Mandala method was adopted based on the concept of complementary opposites to investigate the features extracted from Mandala pattern topology and obtain new features and pseudo-patterns for the screening and early diagnosis of ASD. The optimal feature here was based on different stages of processing and statistical analysis of Pattern Detection Capability (PDC). The PDC is a biomarker derived from the Mandala pattern for differentiating the NC from ASD groups.

scholarly journals The Role of Iron in the Pathogenesis of Autism Spectrum Disorders in Children

2018 ◽  
Vol 17 (4) ◽  
pp. 281-286 ◽  
Author(s):  
Olga V. Kostina
Keyword(s):  
Autism Spectrum Disorders ◽  
Iron Metabolism ◽  
Biochemical Parameters ◽  
Children With Autism ◽  
Neuropsychiatric Disorders ◽  
Perinatal Period ◽  
Autism Spectrum ◽  
Spectrum Disorders ◽  
The Brain

The review presents an analysis of the mechanisms of iron effect on the brain development. The importance of iron deficiency in the perinatal period is considered as a risk factor for the development of neuropsychiatric disorders in children with autism spectrum disorders (ASDs). Possible causes of sideropenia are discussed; data on haematological and biochemical parameters characterizing iron metabolism in children with ASDs are presented. The demand for studying the role of iron metabolism imbalance in the development of neuropsychiatric disorders in order to clarify pathogenetic mechanisms of ASDs and to determine methods for their correction is emphasized.

The epigenetic regulation of synaptic genes contributes to the etiology of autism

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Annamaria Srancikova ◽  
Zuzana Bacova ◽  
Jan Bakos
Keyword(s):  
Epigenetic Regulation ◽  
Neurodevelopmental Disorders ◽  
Autism Spectrum ◽  
Prader Willi Syndrome ◽  
Epigenetic Mechanisms ◽  
Substantial Evidence ◽  
Autistic Symptoms ◽  
Spectrum Disorders ◽  
The Brain

Abstract Epigenetic mechanisms greatly affect the developing brain, as well as the maturation of synapses with pervasive, long-lasting consequences on behavior in adults. Substantial evidence exists that implicates dysregulation of epigenetic mechanisms in the etiology of neurodevelopmental disorders. Therefore, this review explains the role of enzymes involved in DNA methylation and demethylation in neurodevelopment by emphasizing changes of synaptic genes and proteins. Epigenetic causes of sex-dependent differences in the brain are analyzed in conjunction with the pathophysiology of autism spectrum disorders. Special attention is devoted to the epigenetic regulation of the melanoma-associated antigen-like gene 2 (MAGEL2) found in Prader-Willi syndrome, which is known to be accompanied by autistic symptoms.

scholarly journals Reduction of cortical parvalbumin expressing GABAergic interneurons in a rodent hyperoxia model of preterm birth brain injury with deficits in social behavior and cognition

Development ◽  
2021 ◽  
Author(s):  
Till Scheuer ◽  
Elena auf dem Brinke ◽  
Sabine Grosser ◽  
Susanne A. Wolf ◽  
Daniele Mattei ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Psychiatric Symptoms ◽  
Autism Spectrum ◽  
Morphological Properties ◽  
Behavioral Deficits ◽  
Hyperactivity Disorder ◽  
Spectrum Disorders ◽  
The Brain ◽  
Psychiatric Problems ◽  
Behavior And Cognition

The inhibitory GABAergic system in the brain is involved in the etiology of various psychiatric problems, including autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), and others. These disorders are influenced not only by genetic but also by environmental factors, such as preterm birth, although the mechanisms underlying are not known. In a translational hyperoxia model, exposing mice pups at age P5 to 80% oxygen for 48 hours to mimic a steep rise of oxygen exposure caused by preterm birth from in utero into room air, we documented a persistent reduction of cortical mature parvalbumin expressing interneurons until adulthood. Developmental delay of cortical myelin was observed together with decreased expression of oligodendroglial glial cell-derived neurotrophic factor (GDNF), a factor being involved in interneuronal development. Electrophysiological and morphological properties of remaining interneurons were unaffected. Behavioral deficits were observed for social interaction, learning, and attention. These results elucidate that neonatal oxidative stress can lead to decreased interneuron density and to psychiatric symptoms. The obtained cortical myelin deficit and decreased oligodendroglial GDNF expression indicate an impaired oligodendroglial-interneuronal interplay contributes to interneuronal damage.

scholarly journals Gastrointestinal dysfunction in autism displayed by altered motility and achalasia in Foxp1+/− mice

2019 ◽  
Vol 116 (44) ◽  
pp. 22237-22245 ◽  
Author(s):  
Henning Fröhlich ◽  
Marie Luise Kollmeyer ◽  
Valerie Catherine Linz ◽  
Manuel Stuhlinger ◽  
Dieter Groneberg ◽  
...  
Keyword(s):  
Language Impairment ◽  
Muscular Atrophy ◽  
Gastrointestinal Transit ◽  
Autism Spectrum ◽  
Autistic Behavior ◽  
Feeding Difficulties ◽  
Gastrointestinal Problems ◽  
Food And Water Intake ◽  
The Brain

Gastrointestinal dysfunctions in individuals with autism spectrum disorder are poorly understood, although they are common among this group of patients. FOXP1 haploinsufficiency is characterized by autistic behavior, language impairment, and intellectual disability, but feeding difficulties and gastrointestinal problems have also been reported. Whether these are primary impairments, the result of altered eating behavior, or side effects of psychotropic medication remains unclear. To address this question, we investigated Foxp1+/− mice reflecting FOXP1 haploinsufficiency. These animals show decreased body weight and altered feeding behavior with reduced food and water intake. A pronounced muscular atrophy was detected in the esophagus and colon, caused by reduced muscle cell proliferation. Nitric oxide-induced relaxation of the lower esophageal sphincter was impaired and achalasia was confirmed in vivo by manometry. Foxp1 targets (Nexn, Rbms3, and Wls) identified in the brain were dysregulated in the adult Foxp1+/− esophagus. Total gastrointestinal transit was significantly prolonged due to impaired colonic contractility. Our results have uncovered a previously unknown dysfunction (achalasia and impaired gut motility) that explains the gastrointestinal disturbances in patients with FOXP1 syndrome, with potential wider relevance for autism.

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