1
|
Higa GSV, Viana FJC, Francis-Oliveira J, Cruvinel E, Franchin TS, Marcourakis T, Ulrich H, De Pasquale R. Serotonergic neuromodulation of synaptic plasticity. Neuropharmacology 2024; 257:110036. [PMID: 38876308 DOI: 10.1016/j.neuropharm.2024.110036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/15/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024]
Abstract
Synaptic plasticity constitutes a fundamental process in the reorganization of neural networks that underlie memory, cognition, emotional responses, and behavioral planning. At the core of this phenomenon lie Hebbian mechanisms, wherein frequent synaptic stimulation induces long-term potentiation (LTP), while less activation leads to long-term depression (LTD). The synaptic reorganization of neuronal networks is regulated by serotonin (5-HT), a neuromodulator capable of modify synaptic plasticity to appropriately respond to mental and behavioral states, such as alertness, attention, concentration, motivation, and mood. Lately, understanding the serotonergic Neuromodulation of synaptic plasticity has become imperative for unraveling its impact on cognitive, emotional, and behavioral functions. Through a comparative analysis across three main forebrain structures-the hippocampus, amygdala, and prefrontal cortex, this review discusses the actions of 5-HT on synaptic plasticity, offering insights into its role as a neuromodulator involved in emotional and cognitive functions. By distinguishing between plastic and metaplastic effects, we provide a comprehensive overview about the mechanisms of 5-HT neuromodulation of synaptic plasticity and associated functions across different brain regions.
Collapse
Affiliation(s)
- Guilherme Shigueto Vilar Higa
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil; Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Felipe José Costa Viana
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - José Francis-Oliveira
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Emily Cruvinel
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Thainá Soares Franchin
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Tania Marcourakis
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Henning Ulrich
- Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Roberto De Pasquale
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil.
| |
Collapse
|
2
|
Wegiel J, Chadman K, London E, Wisniewski T, Wegiel J. Contribution of the serotonergic system to developmental brain abnormalities in autism spectrum disorder. Autism Res 2024; 17:1300-1321. [PMID: 38500252 PMCID: PMC11272444 DOI: 10.1002/aur.3123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/28/2024] [Indexed: 03/20/2024]
Abstract
This review highlights a key role of the serotonergic system in brain development and in distortions of normal brain development in early stages of fetal life resulting in cascades of abnormalities, including defects of neurogenesis, neuronal migration, neuronal growth, differentiation, and arborization, as well as defective neuronal circuit formation in the cortex, subcortical structures, brainstem, and cerebellum of autistic subjects. In autism, defects in regulation of neuronal growth are the most frequent and ubiquitous developmental changes associated with impaired neuron differentiation, smaller size, distorted shape, loss of spatial orientation, and distortion of cortex organization. Common developmental defects of the brain in autism include multiregional focal dysplastic changes contributing to local neuronal circuit distortion, epileptogenic activity, and epilepsy. There is a discrepancy between more than 500 reports demonstrating the contribution of the serotonergic system to autism's behavioral anomalies, highlighted by lack of studies of autistic subjects' brainstem raphe nuclei, the center of brain serotonergic innervation, and of the contribution of the serotonergic system to the diagnostic features of autism spectrum disorder (ASD). Discovery of severe fetal brainstem auditory system neuronal deficits and other anomalies leading to a spectrum of hearing deficits contributing to a cascade of behavioral alterations, including deficits of social and verbal communication in individuals with autism, is another argument to intensify postmortem studies of the type and topography of, and the severity of developmental defects in raphe nuclei and their contribution to abnormal brain development and to the broad spectrum of functional deficits and comorbid conditions in ASD.
Collapse
Affiliation(s)
- Jarek Wegiel
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA
| | - Kathryn Chadman
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA
| | - Eric London
- Department of Psychology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA
| | - Thomas Wisniewski
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA
- Center for Cognitive Neurology, Department of Neurology, Pathology and Psychiatry, NYU Grossman School of Medicine, New York, New York, USA
| | - Jerzy Wegiel
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA
| |
Collapse
|
3
|
Adiguzel E, Bozkurt NM, Unal G. Independent and combined effects of astaxanthin and omega-3 on behavioral deficits and molecular changes in a prenatal valproic acid model of autism in rats. Nutr Neurosci 2024; 27:590-606. [PMID: 37534957 DOI: 10.1080/1028415x.2023.2239575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Objectives: Autism is a devastating neurodevelopmental disorder and recent studies showed that omega-3 or astaxanthin might reduce autistic symptoms due to their anti-inflammatory properties. Therefore, we investigated the effects of omega-3 and astaxanthin on the VPA-induced autism model of rats.Material and Methods: Female Wistar albino pups (n = 40) were grouped as control, autistic, astaxanthin (2 mg/kg), omega-3 (200 mg/kg), and astaxanthin (2 mg/kg)+omega-3 (200 mg/kg). All groups except the control were prenatally exposed to VPA. Astaxanthin and omega-3 were orally administered from the postnatal day 41 to 68 and behavioral tests were performed between day 69 and 73. The rats were decapitated 24 h after the behavioral tests and hippocampal and prefrontal cytokines and 5-HT levels were analyzed by ELISA.Results: VPA rats have increased grooming behavior while decreased sociability (SI), social preference index (SPI), discrimination index (DI), and prepulse inhibition (PPI) compared to control. Additionally, IL-1β, IL-6, TNF-α, and IFN-γ levels increased while IL-10 and 5-HT levels decreased in both brain regions. Astaxanthin treatment raised SI, SPI, DI, PPI, and prefrontal IL-10 levels. It also raised 5-HT levels and decreased IL-6 levels in both brain regions. Omega-3 and astaxanthin + omega-3 increased the SI, SPI, DI, and PPI and decreased grooming behavior. Moreover, they increased IL-10 and 5-HT levels whereas decreased IL-1β, IL-6, TNF-α, IFN-γ levels in both brain regions.Conclusions: Our results showed that VPA administration mimicked the behavioral and molecular changes of autism in rats. Single and combined administration of astaxanthin and omega-3 improved the autistic-like behavioral and molecular changes in the VPA model of rats.
Collapse
Affiliation(s)
- Emre Adiguzel
- Faculty of Health Sciences, Department of Nutrition and Dietetics, Karamanoğlu Mehmetbey University, Karaman, Türkiye
| | - Nuh Mehmet Bozkurt
- Faculty of Pharmacy, Department of Pharmacology, Erciyes University, Kayseri, Türkiye
- Experimental Research and Application Center (DEKAM), Brain Research Unit, Erciyes University, Kayseri, Türkiye
- e-Neuro Lab, Drug Application and Research Center (ERFARMA), Erciyes University, Kayseri, Türkiye
| | - Gokhan Unal
- Faculty of Pharmacy, Department of Pharmacology, Erciyes University, Kayseri, Türkiye
- Experimental Research and Application Center (DEKAM), Brain Research Unit, Erciyes University, Kayseri, Türkiye
- e-Neuro Lab, Drug Application and Research Center (ERFARMA), Erciyes University, Kayseri, Türkiye
| |
Collapse
|
4
|
Al-Radadi NS, Al-Bishri WM, Salem NA, ElShebiney SA. Plant-mediated green synthesis of gold nanoparticles using an aqueous extract of Passiflora ligularis, optimization, characterizations, and their neuroprotective effect on propionic acid-induced autism in Wistar rats. Saudi Pharm J 2024; 32:101921. [PMID: 38283153 PMCID: PMC10820356 DOI: 10.1016/j.jsps.2023.101921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 12/12/2023] [Indexed: 01/30/2024] Open
Abstract
The current study was conducted to examine an innovative method for synthesizing gold nanoparticles (AuNPs) from an aqueous sweet granadilla (Passiflora ligularis Juss) P. ligularis. Furthermore, the synthesized AuNPs were used to explore their potential neuroprotective impact against propionic acid (PPA)-induced autism. A sweet granadilla extract was used to achieve the synthesis of AuNPs. The structural and dimensional dispersion of AuNPs were confirmed by different techniques, including UV-Vis spectrophotometer (UV-Vis), X-ray Diffraction (XRD) Pattern, Energy Dispersive X-ray (EDX), Zeta potential, and High-Resolution Transmission Electron Microscopy (HRTEM) analysis. The AuNPs mediated by P. ligularis adopt a spherical shape morphology and the particle size was distributed in the range of 8.43-13 nm without aggregation. Moreover, in vivo, the anti-autistic effects of AuNPs administration were higher than those of P. ligularis extract per second. In addition, the reduced anxiety and neurobehavioral deficits of AuNPs were observed in autistic rats which halted the brain oxidative stress, reduced inflammatory cytokines, ameliorated neurotransmitters, and neurochemical release, and suppressed apoptotic genes (p < 0.05). The alleviated antiapoptotic gene expression and histopathological analysis confirmed that the treatment of AuNPs showed significant neural pathways that aid in reducing tissue damage and necrosis. The results emphasize that the biomedical activity was increased by using the green source synthesis P. ligularis -AuNPs. Additionally, the formulation of AuNPs demonstrates strong neuroprotective effects against PPA-induced autism that were arbitrated by a range of different mechanisms, such as anti-inflammatory, antioxidant, neuromodulator, and antiapoptotic effects.
Collapse
Affiliation(s)
- Najlaa S. Al-Radadi
- Department of Chemistry, Faculty of Science, Taibah University, P.O. Box 30002, Al-Madinah Al-Munawarah 14177, Saudi Arabia
| | - Widad M. Al-Bishri
- Department of Biochemistry, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Neveen A. Salem
- Department of Biochemistry, College of Science, University of Jeddah, Jeddah, Saudi Arabia
- Department of Narcotics, Ergogenic Aids and Poisons, Medical Research and Clinical Studies Institute, National Research Centre, Cairo, Egypt
| | - Shaimaa A. ElShebiney
- Department of Narcotics, Ergogenic Aids and Poisons, Medical Research and Clinical Studies Institute, National Research Centre, Cairo, Egypt
| |
Collapse
|
5
|
Zarate-Lopez D, Torres-Chávez AL, Gálvez-Contreras AY, Gonzalez-Perez O. Three Decades of Valproate: A Current Model for Studying Autism Spectrum Disorder. Curr Neuropharmacol 2024; 22:260-289. [PMID: 37873949 PMCID: PMC10788883 DOI: 10.2174/1570159x22666231003121513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 10/25/2023] Open
Abstract
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with increased prevalence and incidence in recent decades. Its etiology remains largely unclear, but it seems to involve a strong genetic component and environmental factors that, in turn, induce epigenetic changes during embryonic and postnatal brain development. In recent decades, clinical studies have shown that inutero exposure to valproic acid (VPA), a commonly prescribed antiepileptic drug, is an environmental factor associated with an increased risk of ASD. Subsequently, prenatal VPA exposure in rodents has been established as a reliable translational model to study the pathophysiology of ASD, which has helped demonstrate neurobiological changes in rodents, non-human primates, and brain organoids from human pluripotent stem cells. This evidence supports the notion that prenatal VPA exposure is a valid and current model to replicate an idiopathic ASD-like disorder in experimental animals. This review summarizes and describes the current features reported with this animal model of autism and the main neurobiological findings and correlates that help elucidate the pathophysiology of ASD. Finally, we discuss the general framework of the VPA model in comparison to other environmental and genetic ASD models.
Collapse
Affiliation(s)
- David Zarate-Lopez
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima 28040, México
- Physiological Science Ph.D. Program, School of Medicine, University of Colima, Colima 28040, Mexico
| | - Ana Laura Torres-Chávez
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima 28040, México
- Physiological Science Ph.D. Program, School of Medicine, University of Colima, Colima 28040, Mexico
| | - Alma Yadira Gálvez-Contreras
- Department of Neuroscience, Centro Universitario de Ciencias de la Salud, University of Guadalajara, Guadalajara 44340, México
| | - Oscar Gonzalez-Perez
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima 28040, México
| |
Collapse
|
6
|
Beopoulos A, Géa M, Fasano A, Iris F. Autism spectrum disorders pathogenesis: Toward a comprehensive model based on neuroanatomic and neurodevelopment considerations. Front Neurosci 2022; 16:988735. [PMID: 36408388 PMCID: PMC9671112 DOI: 10.3389/fnins.2022.988735] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/10/2022] [Indexed: 11/26/2023] Open
Abstract
Autism spectrum disorder (ASD) involves alterations in neural connectivity affecting cortical network organization and excitation to inhibition ratio. It is characterized by an early increase in brain volume mediated by abnormal cortical overgrowth patterns and by increases in size, spine density, and neuron population in the amygdala and surrounding nuclei. Neuronal expansion is followed by a rapid decline from adolescence to middle age. Since no known neurobiological mechanism in human postnatal life is capable of generating large excesses of frontocortical neurons, this likely occurs due to a dysregulation of layer formation and layer-specific neuronal migration during key early stages of prenatal cerebral cortex development. This leads to the dysregulation of post-natal synaptic pruning and results in a huge variety of forms and degrees of signal-over-noise discrimination losses, accounting for ASD clinical heterogeneities, including autonomic nervous system abnormalities and comorbidities. We postulate that sudden changes in environmental conditions linked to serotonin/kynurenine supply to the developing fetus, throughout the critical GW7 - GW20 (Gestational Week) developmental window, are likely to promote ASD pathogenesis during fetal brain development. This appears to be driven by discrete alterations in differentiation and patterning mechanisms arising from in utero RNA editing, favoring vulnerability outcomes over plasticity outcomes. This paper attempts to provide a comprehensive model of the pathogenesis and progression of ASD neurodevelopmental disorders.
Collapse
Affiliation(s)
| | | | - Alessio Fasano
- Division of Pediatric Gastroenterology and Nutrition, Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Boston, MA, United States
- Division of Pediatric Gastroenterology and Nutrition, Center for Celiac Research and Treatment, Massachusetts General Hospital for Children, Boston, MA, United States
| | | |
Collapse
|
7
|
Alachkar A. Aromatic patterns: Tryptophan aromaticity as a catalyst for the emergence of life and rise of consciousness. Phys Life Rev 2022; 42:93-114. [PMID: 35905538 DOI: 10.1016/j.plrev.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 11/28/2022]
Abstract
Sunlight held the key to the origin of life on Earth. The earliest life forms, cyanobacteria, captured the sunlight to generate energy through photosynthesis. Life on Earth evolved in accordance with the circadian rhythms tied to sensitivity to sunlight patterns. A unique feature of cyanobacterial photosynthetic proteins and circadian rhythms' molecules, and later of nearly all photon-sensing molecules throughout evolution, is that the aromatic amino acid tryptophan (Trp) resides at the center of light-harvesting active sites. In this perspective, I review the literature and integrate evidence from different scientific fields to explore the role Trp plays in photon-sensing capabilities of living organisms through its resonance delocalization of π-electrons. The observations presented here are the product of apparently unrelated phenomena throughout evolution, but nevertheless share consistent patterns of photon-sensing by Trp-containing and Trp-derived molecules. I posit the unique capacity to transfer electrons during photosynthesis in the earliest life forms is conferred to Trp due to its aromaticity. I propose this ability evolved to assume more complex functions, serving as a host for mechanisms underlying mental aptitudes - a concept which provides a theoretical basis for defining the neural correlates of consciousness. The argument made here is that Trp aromaticity may have allowed for the inception of the mechanistic building blocks used to fabricate complexity in higher forms of life. More specifically, Trp aromatic non-locality may have acted as a catalyst for the emergence of consciousness by instigating long-range synchronization and stabilizing the large-scale coherence of neural networks, which mediate functional brain activity. The concepts proposed in this perspective provide a conceptual foundation that invites further interdisciplinary dialogue aimed at examining and defining the role of aromaticity (beyond Trp) in the emergence of life and consciousness.
Collapse
Affiliation(s)
- Amal Alachkar
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, CA 92697, USA; UC Irvine Center for the Neurobiology of Learning and Memory, University of California-Irvine, Irvine, CA 92697, USA; Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California, Irvine, CA 92697, USA.
| |
Collapse
|
8
|
Juvenile handling rescues autism-related effects of prenatal exposure to valproic acid. Sci Rep 2022; 12:7174. [PMID: 35504947 PMCID: PMC9065111 DOI: 10.1038/s41598-022-11269-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/13/2022] [Indexed: 11/12/2022] Open
Abstract
Environmental factors acting on young animals affect neurodevelopmental trajectories and impact adult brain function and behavior. Psychiatric disorders may be caused or worsen by environmental factors, but early interventions can improve performance. Understanding the possible mechanisms acting upon the developing brain could help identify etiological factors of psychiatric disorders and enable advancement of effective therapies. Research has focused on the long-lasting effects of environmental factors acting during the perinatal period, therefore little is known about the impact of these factors at later ages when neurodevelopmental pathologies such as autism spectrum disorder (ASD) are usually diagnosed. Here we show that handling mice during the juvenile period can rescue a range of behavioral and cellular effects of prenatal valproic acid (VPA) exposure. VPA-exposed animals show reduced sociability and increased repetitive behaviors, along with other autism-related endophenotypes such as increased immobility in the forced swim test and increased neuronal activity in the piriform cortex (Pir). Our results demonstrate that briefly handling mice every other day between postnatal days 22 and 34 can largely rescue these phenotypes. This effect can also be observed when animals are analyzed across tests using an “autism” factor, which also discriminates between animals with high and low Pir neuron activity. Thus, we identified a juvenile developmental window when environmental factors can determine adult autism-related behavior. In addition, our results have broader implications on behavioral neuroscience, as they highlight the importance of adequate experimental design and control of behavioral experiments involving treating or testing young animals.
Collapse
|
9
|
Therapeutic Effects of a Novel Form of Biotin on Propionic Acid-Induced Autistic Features in Rats. Nutrients 2022; 14:nu14061280. [PMID: 35334937 PMCID: PMC8955994 DOI: 10.3390/nu14061280] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 12/04/2022] Open
Abstract
Magnesium biotinate (MgB) is a novel biotin complex with superior absorption and anti-inflammatory effects in the brain than D-Biotin. This study aimed to investigate the impact of different doses of MgB on social behavior deficits, learning and memory alteration, and inflammatory markers in propionic acid (PPA)-exposed rats. In this case, 35 Wistar rats (3 weeks old) were distributed into five groups: 1, Control; 2, PPA treated group; 3, PPA+MgBI (10 mg, HED); 4, PPA+MgBII (100 mg, HED); 5, PPA+MgBIII (500 mg, HED). PPA was given subcutaneously at 500 mg/kg/day for five days, followed by MgB for two weeks. PPA-exposed rats showed poor sociability and a high level of anxiety-like behaviors and cognitive impairments (p < 0.001). In a dose-dependent manner, behavioral and learning-memory disorders were significantly improved by MgB supplementation (p < 0.05). PPA decreased both the numbers and the sizes of Purkinje cells in the cerebellum. However, MgB administration increased the sizes and the densities of Purkinje cells. MgB improved the brain and serum Mg, biotin, serotonin, and dopamine concentrations, as well as antioxidant enzymes (CAT, SOD, GPx, and GSH) (p < 0.05). In addition, MgB treatment significantly regulated the neurotoxicity-related cytokines and neurotransmission-related markers. For instance, MgB significantly decreased the expression level of TNF-α, IL-6, IL-17, CCL-3, CCL-5, and CXCL-16 in the brain, compared to the control group (p < 0.05). These data demonstrate that MgB may ameliorate dysfunctions in social behavior, learning and memory and reduce the oxidative stress and inflammation indexes of the brain in a rat model.
Collapse
|
10
|
Pathophysiological Studies of Monoaminergic Neurotransmission Systems in Valproic Acid-Induced Model of Autism Spectrum Disorder. Biomedicines 2022; 10:biomedicines10030560. [PMID: 35327362 PMCID: PMC8945169 DOI: 10.3390/biomedicines10030560] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 01/27/2023] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with complex etiology. The core syndromes of ASD are deficits in social communication and self-restricted interests and repetitive behaviors. Social communication relies on the proper integration of sensory and motor functions, which is tightly interwoven with the limbic function of reward, motivation, and emotion in the brain. Monoamine neurotransmitters, including serotonin, dopamine, and norepinephrine, are key players in the modulation of neuronal activity. Owing to their broad distribution, the monoamine neurotransmitter systems are well suited to modulate social communication by coordinating sensory, motor, and limbic systems in different brain regions. The complex and diverse functions of monoamine neurotransmission thus render themselves as primary targets of pathophysiological investigation of the etiology of ASD. Clinical studies have reported that children with maternal exposure to valproic acid (VPA) have an increased risk of developing ASD. Extensive animal studies have confirmed that maternal treatments of VPA include ASD-like phenotypes, including impaired social communication and repetitive behavior. Here, given that ASD is a neurodevelopmental disorder, we begin with an overview of the neural development of monoaminergic systems with their neurochemical properties in the brain. We then review and discuss the evidence of human clinical and animal model studies of ASD with a focus on the VPA-induced pathophysiology of monoamine neurotransmitter systems. We also review the potential interactions of microbiota and monoamine neurotransmitter systems in ASD pathophysiology. Widespread and complex changes in monoamine neurotransmitters are detected in the brains of human patients with ASD and validated in animal models. ASD animal models are not only essential to the characterization of pathogenic mechanisms, but also provide a preclinical platform for developing therapeutic approaches to ASD.
Collapse
|
11
|
Baizer JS. Functional and Neuropathological Evidence for a Role of the Brainstem in Autism. Front Integr Neurosci 2021; 15:748977. [PMID: 34744648 PMCID: PMC8565487 DOI: 10.3389/fnint.2021.748977] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/21/2021] [Indexed: 12/27/2022] Open
Abstract
The brainstem includes many nuclei and fiber tracts that mediate a wide range of functions. Data from two parallel approaches to the study of autistic spectrum disorder (ASD) implicate many brainstem structures. The first approach is to identify the functions affected in ASD and then trace the neural systems mediating those functions. While not included as core symptoms, three areas of function are frequently impaired in ASD: (1) Motor control both of the limbs and body and the control of eye movements; (2) Sensory information processing in vestibular and auditory systems; (3) Control of affect. There are critical brainstem nuclei mediating each of those functions. There are many nuclei critical for eye movement control including the superior colliculus. Vestibular information is first processed in the four nuclei of the vestibular nuclear complex. Auditory information is relayed to the dorsal and ventral cochlear nuclei and subsequently processed in multiple other brainstem nuclei. Critical structures in affect regulation are the brainstem sources of serotonin and norepinephrine, the raphe nuclei and the locus ceruleus. The second approach is the analysis of abnormalities from direct study of ASD brains. The structure most commonly identified as abnormal in neuropathological studies is the cerebellum. It is classically a major component of the motor system, critical for coordination. It has also been implicated in cognitive and language functions, among the core symptoms of ASD. This structure works very closely with the cerebral cortex; the cortex and the cerebellum show parallel enlargement over evolution. The cerebellum receives input from cortex via relays in the pontine nuclei. In addition, climbing fiber input to cerebellum comes from the inferior olive of the medulla. Mossy fiber input comes from the arcuate nucleus of the medulla as well as the pontine nuclei. The cerebellum projects to several brainstem nuclei including the vestibular nuclear complex and the red nucleus. There are thus multiple brainstem nuclei distributed at all levels of the brainstem, medulla, pons, and midbrain, that participate in functions affected in ASD. There is direct evidence that the cerebellum may be abnormal in ASD. The evidence strongly indicates that analysis of these structures could add to our understanding of the neural basis of ASD.
Collapse
Affiliation(s)
- Joan S. Baizer
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| |
Collapse
|
12
|
Fetit R, Hillary RF, Price DJ, Lawrie SM. The neuropathology of autism: A systematic review of post-mortem studies of autism and related disorders. Neurosci Biobehav Rev 2021; 129:35-62. [PMID: 34273379 DOI: 10.1016/j.neubiorev.2021.07.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/13/2021] [Accepted: 07/10/2021] [Indexed: 02/07/2023]
Abstract
Post-mortem studies allow for the direct investigation of brain tissue in those with autism and related disorders. Several review articles have focused on aspects of post-mortem abnormalities but none has brought together the entire post-mortem literature. Here, we systematically review the evidence from post-mortem studies of autism, and of related disorders that present with autistic features. The literature consists of a small body of studies with small sample sizes, but several remarkably consistent findings are evident. Cortical layering is largely undisturbed, but there are consistent reductions in minicolumn numbers and aberrant myelination. Transcriptomics repeatedly implicate abberant synaptic, metabolic, proliferation, apoptosis and immune pathways. Sufficient replicated evidence is available to implicate non-coding RNA, aberrant epigenetic profiles, GABAergic, glutamatergic and glial dysfunction in autism pathogenesis. Overall, the cerebellum and frontal cortex are most consistently implicated, sometimes revealing distinct region-specific alterations. The literature on related disorders such as Rett syndrome, Fragile X and copy number variations (CNVs) predisposing to autism is particularly small and inconclusive. Larger studies, matched for gender, developmental stage, co-morbidities and drug treatment are required.
Collapse
Affiliation(s)
- Rana Fetit
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.
| | - Robert F Hillary
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - David J Price
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Stephen M Lawrie
- Division of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH10 5HF, UK; Patrick Wild Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH10 5HF, UK
| |
Collapse
|
13
|
Lew CH, Groeniger KM, Hanson KL, Cuevas D, Greiner DMZ, Hrvoj-Mihic B, Bellugi U, Schumann CM, Semendeferi K. Serotonergic innervation of the amygdala is increased in autism spectrum disorder and decreased in Williams syndrome. Mol Autism 2020; 11:12. [PMID: 32024554 PMCID: PMC7003328 DOI: 10.1186/s13229-019-0302-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/04/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Williams syndrome (WS) and autism spectrum disorder (ASD) are neurodevelopmental disorders that demonstrate overlapping genetic associations, dichotomous sociobehavioral phenotypes, and dichotomous pathological differences in neuronal distribution in key social brain areas, including the prefrontal cortex and the amygdala. The serotonergic system is critical to many processes underlying neurodevelopment and is additionally an important neuromodulator associated with behavioral variation. The amygdala is heavily innervated by serotonergic projections, suggesting that the serotonergic system is a significant mediator of neuronal activity. Disruptions to the serotonergic system, and atypical structure and function of the amygdala, are implicated in both WS and ASD. METHODS We quantified the serotonergic axon density in the four major subdivisions of the amygdala in the postmortem brains of individuals diagnosed with ASD and WS and neurotypical (NT) brains. RESULTS We found opposing directions of change in serotonergic innervation in the two disorders, with ASD displaying an increase in serotonergic axons compared to NT and WS displaying a decrease. Significant differences (p < 0.05) were observed between WS and ASD data sets across multiple amygdala nuclei. LIMITATIONS This study is limited by the availability of human postmortem tissue. Small sample size is an unavoidable limitation of most postmortem human brain research and particularly postmortem research in rare disorders. CONCLUSIONS Differential alterations to serotonergic innervation of the amygdala may contribute to differences in sociobehavioral phenotype in WS and ASD. These findings will inform future work identifying targets for future therapeutics in these and other disorders characterized by atypical social behavior.
Collapse
Affiliation(s)
- C H Lew
- Department of Anthropology, University of California, San Diego, USA
| | - K M Groeniger
- Department of Anthropology, University of California, San Diego, USA
| | - K L Hanson
- Department of Anthropology, University of California, San Diego, USA
| | - D Cuevas
- Department of Biological Sciences, University of California, San Diego, USA
| | - D M Z Greiner
- Department of Biological Sciences, University of California, San Diego, USA
| | - B Hrvoj-Mihic
- Department of Anthropology, University of California, San Diego, USA
| | - U Bellugi
- Salk Institute for Biological Sciences, San Diego, USA
| | - C M Schumann
- Department of Psychiatry and Behavioral Sciences, University of California, Davis School of Medicine, the MIND Institute, Sacramento, USA
| | - K Semendeferi
- Department of Anthropology, University of California, San Diego, USA.
| |
Collapse
|
14
|
Vahid-Ansari F, Zhang M, Zahrai A, Albert PR. Overcoming Resistance to Selective Serotonin Reuptake Inhibitors: Targeting Serotonin, Serotonin-1A Receptors and Adult Neuroplasticity. Front Neurosci 2019; 13:404. [PMID: 31114473 PMCID: PMC6502905 DOI: 10.3389/fnins.2019.00404] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/09/2019] [Indexed: 12/14/2022] Open
Abstract
Major depressive disorder (MDD) is the most prevalent mental illness contributing to global disease burden. Selective serotonin (5-HT) reuptake inhibitors (SSRIs) are the first-line treatment for MDD, but are only fully effective in 30% of patients and require weeks before improvement may be seen. About 30% of SSRI-resistant patients may respond to augmentation or switching to another antidepressant, often selected by trial and error. Hence a better understanding of the causes of SSRI resistance is needed to provide models for optimizing treatment. Since SSRIs enhance 5-HT, in this review we discuss new findings on the circuitry, development and function of the 5-HT system in modulating behavior, and on how 5-HT neuronal activity is regulated. We focus on the 5-HT1A autoreceptor, which controls 5-HT activity, and the 5-HT1A heteroreceptor that mediates 5-HT actions. A series of mice models now implicate increased levels of 5-HT1A autoreceptors in SSRI resistance, and the requirement of hippocampal 5-HT1A heteroreceptor for neurogenic and behavioral response to SSRIs. We also present clinical data that show promise for identifying biomarkers of 5-HT activity, 5-HT1A regulation and regional changes in brain activity in MDD patients that may provide biomarkers for tailored interventions to overcome or bypass resistance to SSRI treatment. We identify a series of potential strategies including inhibiting 5-HT auto-inhibition, stimulating 5-HT1A heteroreceptors, other monoamine systems, or cortical stimulation to overcome SSRI resistance.
Collapse
Affiliation(s)
| | | | | | - Paul R. Albert
- Brain and Mind Research Institute, Ottawa Hospital Research Institute (Neuroscience), University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
15
|
Dadalko OI, Travers BG. Evidence for Brainstem Contributions to Autism Spectrum Disorders. Front Integr Neurosci 2018; 12:47. [PMID: 30337860 PMCID: PMC6180283 DOI: 10.3389/fnint.2018.00047] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/18/2018] [Indexed: 12/27/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition that affects one in 59 children in the United States. Although there is a mounting body of knowledge of cortical and cerebellar contributions to ASD, our knowledge about the early developing brainstem in ASD is only beginning to accumulate. Understanding how brainstem neurotransmission is implicated in ASD is important because many of this condition’s sensory and motor symptoms are consistent with brainstem pathology. Therefore, the purpose of this review was to integrate epidemiological, behavioral, histological, neuroimaging, and animal evidence of brainstem contributions to ASD. Because ASD is a neurodevelopmental condition, we examined the available data through a lens of hierarchical brain development. The review of the literature suggests that developmental alterations of the brainstem could have potential cascading effects on cortical and cerebellar formation, ultimately leading to ASD symptoms. This view is supported by human epidemiology findings and data from animal models of ASD, showing that perturbed development of the brainstem substructures, particularly during the peak formation of the brainstem’s monoaminergic centers, may relate to ASD or ASD-like behaviors. Furthermore, we review evidence from human histology, psychophysiology, and neuroimaging suggesting that brainstem development and maturation may be atypical in ASD and may be related to key ASD symptoms, such as atypical sensorimotor features and social responsiveness. From this review there emerges the need of future research to validate early detection of the brainstem-based somatosensory and psychophysiological behaviors that emerge in infancy, and to examine the brainstem across the life span, while accounting for age. In all, there is preliminary evidence for brainstem involvement in ASD, but a better understanding of the brainstem’s role would likely pave the way for earlier diagnosis and treatment of ASD.
Collapse
Affiliation(s)
- Olga I Dadalko
- Motor and Brain Development Lab, Waisman Center, University of Wisconsin-Madison, Madison, WI, United States
| | - Brittany G Travers
- Motor and Brain Development Lab, Occupational Therapy Program in the Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, United States
| |
Collapse
|
16
|
Janušonis S, Detering N. A stochastic approach to serotonergic fibers in mental disorders. Biochimie 2018; 161:15-22. [PMID: 30056260 DOI: 10.1016/j.biochi.2018.07.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 07/24/2018] [Indexed: 01/09/2023]
Abstract
Virtually all brain circuits are physically embedded in a three-dimensional matrix of fibers that release 5-hydroxytryptamine (5-HT, serotonin). The density of this matrix varies across brain regions and cortical laminae, and it is altered in some mental disorders, including Major Depressive Disorder and Autism Spectrum Disorder. We investigate how the regional structure of the serotonergic matrix depends on the stochastic behavior of individual serotonergic fibers and introduce a new framework for the quantitative analysis of this behavior. In particular, we show that a step-wise random walk, based on the von Mises-Fisher probability distribution, can provide a realistic and mathematically concise description of these fibers. We also consider other stochastic models, including the fractional Brownian motion. The proposed approach seeks to advance the current understanding of the ascending reticular activating system (ARAS) and may also support future theory-guided therapeutic approaches.
Collapse
Affiliation(s)
- Skirmantas Janušonis
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, 93106-9660, USA.
| | - Nils Detering
- Department of Statistics and Applied Probability, University of California, Santa Barbara, CA, 93106-3110, USA
| |
Collapse
|
17
|
Varghese M, Keshav N, Jacot-Descombes S, Warda T, Wicinski B, Dickstein DL, Harony-Nicolas H, De Rubeis S, Drapeau E, Buxbaum JD, Hof PR. Autism spectrum disorder: neuropathology and animal models. Acta Neuropathol 2017; 134:537-566. [PMID: 28584888 PMCID: PMC5693718 DOI: 10.1007/s00401-017-1736-4] [Citation(s) in RCA: 293] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/30/2017] [Accepted: 05/31/2017] [Indexed: 12/13/2022]
Abstract
Autism spectrum disorder (ASD) has a major impact on the development and social integration of affected individuals and is the most heritable of psychiatric disorders. An increase in the incidence of ASD cases has prompted a surge in research efforts on the underlying neuropathologic processes. We present an overview of current findings in neuropathology studies of ASD using two investigational approaches, postmortem human brains and ASD animal models, and discuss the overlap, limitations, and significance of each. Postmortem examination of ASD brains has revealed global changes including disorganized gray and white matter, increased number of neurons, decreased volume of neuronal soma, and increased neuropil, the last reflecting changes in densities of dendritic spines, cerebral vasculature and glia. Both cortical and non-cortical areas show region-specific abnormalities in neuronal morphology and cytoarchitectural organization, with consistent findings reported from the prefrontal cortex, fusiform gyrus, frontoinsular cortex, cingulate cortex, hippocampus, amygdala, cerebellum and brainstem. The paucity of postmortem human studies linking neuropathology to the underlying etiology has been partly addressed using animal models to explore the impact of genetic and non-genetic factors clinically relevant for the ASD phenotype. Genetically modified models include those based on well-studied monogenic ASD genes (NLGN3, NLGN4, NRXN1, CNTNAP2, SHANK3, MECP2, FMR1, TSC1/2), emerging risk genes (CHD8, SCN2A, SYNGAP1, ARID1B, GRIN2B, DSCAM, TBR1), and copy number variants (15q11-q13 deletion, 15q13.3 microdeletion, 15q11-13 duplication, 16p11.2 deletion and duplication, 22q11.2 deletion). Models of idiopathic ASD include inbred rodent strains that mimic ASD behaviors as well as models developed by environmental interventions such as prenatal exposure to sodium valproate, maternal autoantibodies, and maternal immune activation. In addition to replicating some of the neuropathologic features seen in postmortem studies, a common finding in several animal models of ASD is altered density of dendritic spines, with the direction of the change depending on the specific genetic modification, age and brain region. Overall, postmortem neuropathologic studies with larger sample sizes representative of the various ASD risk genes and diverse clinical phenotypes are warranted to clarify putative etiopathogenic pathways further and to promote the emergence of clinically relevant diagnostic and therapeutic tools. In addition, as genetic alterations may render certain individuals more vulnerable to developing the pathological changes at the synapse underlying the behavioral manifestations of ASD, neuropathologic investigation using genetically modified animal models will help to improve our understanding of the disease mechanisms and enhance the development of targeted treatments.
Collapse
Affiliation(s)
- Merina Varghese
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Neha Keshav
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Sarah Jacot-Descombes
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Unit of Psychiatry, Department of Children and Teenagers, University Hospitals and School of Medicine, Geneva, CH-1205, Switzerland
| | - Tahia Warda
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Bridget Wicinski
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Dara L Dickstein
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Hala Harony-Nicolas
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Silvia De Rubeis
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Elodie Drapeau
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Joseph D Buxbaum
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Patrick R Hof
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA.
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| |
Collapse
|
18
|
Azmitia EC, Saccomano ZT, Alzoobaee MF, Boldrini M, Whitaker-Azmitia PM. Persistent Angiogenesis in the Autism Brain: An Immunocytochemical Study of Postmortem Cortex, Brainstem and Cerebellum. J Autism Dev Disord 2016; 46:1307-18. [PMID: 26667147 PMCID: PMC4836621 DOI: 10.1007/s10803-015-2672-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the current work, we conducted an immunocytochemical search for markers of ongoing neurogenesis (e.g. nestin) in auditory cortex from postmortem sections of autism spectrum disorder (ASD) and age-matched control donors. We found nestin labeling in cells of the vascular system, indicating blood vessels plasticity. Evidence of angiogenesis was seen throughout superior temporal cortex (primary auditory cortex), fusiform cortex (face recognition center), pons/midbrain and cerebellum in postmortem brains from ASD patients but not control brains. We found significant increases in both nestin and CD34, which are markers of angiogenesis localized to pericyte cells and endothelial cells, respectively. This labeling profile is indicative of splitting (intussusceptive), rather than sprouting, angiogenesis indicating the blood vessels are in constant flux rather than continually expanding.
Collapse
Affiliation(s)
- E C Azmitia
- Departments of Biology and Psychiatry, New York University, 100 Washington Square East, New York, NY, 10003, USA.
| | - Z T Saccomano
- Departments of Biology and Psychiatry, New York University, 100 Washington Square East, New York, NY, 10003, USA
| | - M F Alzoobaee
- Departments of Biology and Psychiatry, New York University, 100 Washington Square East, New York, NY, 10003, USA
| | - M Boldrini
- Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
| | - P M Whitaker-Azmitia
- Departments of Psychology Program in Integrative Neuroscience, and Psychiatry, Stony Brook University, Stony Brook, NY, 11794, USA
| |
Collapse
|
19
|
Hough LH, Segal S. Effects of developmental hyperserotonemia on the morphology of rat dentate nuclear neurons. Neuroscience 2016; 322:178-94. [PMID: 26892293 DOI: 10.1016/j.neuroscience.2016.02.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/14/2016] [Accepted: 02/10/2016] [Indexed: 11/18/2022]
Abstract
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social cognition, disordered communication, restricted interests and repetitive behaviors. Furthermore, abnormalities in basic motor control, skilled motor gestures, and motor learning, are common in ASD. These characteristics have been attributed to a possible defect in the pre- and postnatal development of specific neural networks including the dentate-thalamo-cortical pathway, which is involved in motor learning, automaticity of movements, and higher cognitive functions. The current study utilized custom diolistic labeling and unbiased stereology to characterize morphological alterations in neurons of the dentate nucleus of the cerebellum in developing rat pups exposed to abnormally high levels of the serotonergic agonist 5-methyloxytryptamine (5-MT) pre-and postnatally. Occurring in as many as 30% of autistic subjects, developmental hyperserotonemia (DHS) is the most consistent neurochemical finding reported in autism and has been implicated in the pathophysiology of ASD. This exposure produced dramatic changes in dendritic architecture and synaptic features. We observed changes in the dendritic branching morphology which did not lead to significant differences (p>0.5) in total dendritic length. Instead, DHS groups presented with dendritic trees that display changes in arborescence, that appear to be short reaching with elaborately branched segments, presenting with significantly fewer (p>0.001) dendritic spines and a decrease in numeric density when compared to age-matched controls. These negative changes may be implicated in the neuropathological and functional/behavioral changes observed in ASD, such as delays in motor learning, difficulties in automaticity of movements, and deficits in higher cognitive functions.
Collapse
Affiliation(s)
- L H Hough
- Department of Biomedical Sciences, Missouri State University, Springfield, MO 65897, USA.
| | - S Segal
- Department of Surgery, Center for Anatomical Sciences and Education, Saint Louis University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
20
|
Wicker B, Monfardini E, Royet JP. Olfactory processing in adults with autism spectrum disorders. Mol Autism 2016; 7:4. [PMID: 26788281 PMCID: PMC4717566 DOI: 10.1186/s13229-016-0070-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 01/12/2016] [Indexed: 12/04/2022] Open
Abstract
Background As evidenced in the DSM-V, autism spectrum disorders (ASD) are often characterized by atypical sensory behavior (hyper- or hypo-reactivity), but very few studies have evaluated olfactory abilities in individuals with ASD. Methods Fifteen adults with ASD and 15 typically developing participants underwent olfactory tests focused on superficial (suprathreshold detection task), perceptual (intensity and pleasantness judgment tasks), and semantic (identification task) odor processing. Results In terms of suprathreshold detection performance, decreased discrimination scores and increased bias scores were observed in the ASD group. Furthermore, the participants with ASD exhibited increased intensity judgment scores and impaired scores for pleasantness judgments of unpleasant odorants. Decreased identification performance was also observed in the participants with ASD compared with the typically developing participants. This decrease was partly attributed to a higher number of near misses (a category close to veridical labels) among the participants with ASD than was observed among the typically developing participants. Conclusions The changes in discrimination and bias scores were the result of a high number of false alarms among the participants with ASD, which suggests the adoption of a liberal attitude in their responses. Atypical intensity and pleasantness ratings were associated with hyperresponsiveness and flattened emotional reactions, respectively, which are typical of participants with ASD. The high number of near misses as non-veridical labels suggested that categorical processing is functional in individuals with ASD and could be explained by attention-deficit/hyperactivity disorder. These findings are discussed in terms of dysfunction of the olfactory system.
Collapse
Affiliation(s)
- Bruno Wicker
- Institut de Neurosciences de la Timone. CNRS & Université Aix-Marseille, Campus Santé Timone 27, Boulevard Jean Moulin, 13385 Marseille cedex 05, France
| | - Elisabetta Monfardini
- Integrative, Multisensory, Perception, Action and Cognition Team, Lyon, F-69000 France ; University Lyon 1, Lyon, F-69000 France ; Institut de Médecine Environnementale, Paris, France
| | - Jean-Pierre Royet
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Olfaction : From Coding to Memory Team, Lyon, F-69000 France ; University Lyon 1, Lyon, F-69000 France
| |
Collapse
|
21
|
Neurobiological abnormalities in the first few years of life in individuals later diagnosed with autism spectrum disorder: a review of recent data. Behav Neurol 2014; 2014:210780. [PMID: 24825948 PMCID: PMC4006615 DOI: 10.1155/2014/210780] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 06/23/2013] [Indexed: 02/07/2023] Open
Abstract
Background. Despite the widely-held understanding that the biological changes that lead to autism usually occur during prenatal life, there has been relatively little research into the functional development of the brain during early infancy in individuals later diagnosed with autism spectrum disorder (ASD). Objective. This review explores the studies over the last three years which have investigated differences in various brain regions in individuals with ASD or who later go on to receive a diagnosis of ASD. Methods. We used PRISMA guidelines and selected published articles reporting any neurological abnormalities in very early childhood in individuals with or later diagnosed with ASD. Results. Various brain regions are discussed including the amygdala, cerebellum, frontal cortex, and lateralised abnormalities of the temporal cortex during language processing. This review discusses studies investigating head circumference, electrophysiological markers, and interhemispheric synchronisation. All of the recent findings from the beginning of 2009 across these different aspects of defining neurological abnormalities are discussed in light of earlier findings. Conclusions. The studies across these different areas reveal the existence of atypicalities in the first year of life, well before ASD is reliably diagnosed. Cross-disciplinary approaches are essential to elucidate the pathophysiological sequence of events that lead to ASD.
Collapse
|
22
|
Paemka L, Mahajan VB, Skeie JM, Sowers LP, Ehaideb SN, Gonzalez-Alegre P, Sasaoka T, Tao H, Miyagi A, Ueno N, Takao K, Miyakawa T, Wu S, Darbro BW, Ferguson PJ, Pieper AA, Britt JK, Wemmie JA, Rudd DS, Wassink T, El-Shanti H, Mefford HC, Carvill GL, Manak JR, Bassuk AG. PRICKLE1 interaction with SYNAPSIN I reveals a role in autism spectrum disorders. PLoS One 2013; 8:e80737. [PMID: 24312498 PMCID: PMC3849077 DOI: 10.1371/journal.pone.0080737] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 10/04/2013] [Indexed: 11/18/2022] Open
Abstract
The frequent comorbidity of Autism Spectrum Disorders (ASDs) with epilepsy suggests a shared underlying genetic susceptibility; several genes, when mutated, can contribute to both disorders. Recently, PRICKLE1 missense mutations were found to segregate with ASD. However, the mechanism by which mutations in this gene might contribute to ASD is unknown. To elucidate the role of PRICKLE1 in ASDs, we carried out studies in Prickle1(+/-) mice and Drosophila, yeast, and neuronal cell lines. We show that mice with Prickle1 mutations exhibit ASD-like behaviors. To find proteins that interact with PRICKLE1 in the central nervous system, we performed a yeast two-hybrid screen with a human brain cDNA library and isolated a peptide with homology to SYNAPSIN I (SYN1), a protein involved in synaptogenesis, synaptic vesicle formation, and regulation of neurotransmitter release. Endogenous Prickle1 and Syn1 co-localize in neurons and physically interact via the SYN1 region mutated in ASD and epilepsy. Finally, a mutation in PRICKLE1 disrupts its ability to increase the size of dense-core vesicles in PC12 cells. Taken together, these findings suggest PRICKLE1 mutations contribute to ASD by disrupting the interaction with SYN1 and regulation of synaptic vesicles.
Collapse
Affiliation(s)
- Lily Paemka
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Program in Genetics, The University of Iowa, Iowa City, Iowa, United States of America
| | - Vinit B. Mahajan
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
| | - Jessica M. Skeie
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States of America
| | - Levi P. Sowers
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Neurology, The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
| | - Salleh N. Ehaideb
- The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Program in Genetics, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Pedro Gonzalez-Alegre
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Neurology, The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Graduate Program of Neuroscience, The University of Iowa, Iowa City, Iowa, United States of America
| | - Toshikuni Sasaoka
- Center for Bioresources, Brain Research Institute, Niigata University, Niigata, Japan
| | - Hirotaka Tao
- Hospital for Sick Kids, University of Toronto, Toronto, Canada
| | - Asuka Miyagi
- Developmental Biology Department, National Institute for Basic Biology, Okazaki City, Japan
| | - Naoto Ueno
- Developmental Biology Department, National Institute for Basic Biology, Okazaki City, Japan
| | - Keizo Takao
- Section of Behavior Patterns, Center for Genetic Analysis of Behavior National Institute for Physiological Sciences, Okazaki, Japan
- Japan Science and Technology Agency, Kawaguchi-shi, Japan
| | - Tsuyoshi Miyakawa
- Section of Behavior Patterns, Center for Genetic Analysis of Behavior National Institute for Physiological Sciences, Okazaki, Japan
- Japan Science and Technology Agency, Kawaguchi-shi, Japan
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan
| | - Shu Wu
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, The University of Iowa, Iowa City, Iowa, United States of America
| | - Benjamin W. Darbro
- The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Pathology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Polly J. Ferguson
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
| | - Andrew A. Pieper
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Neurology, The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa, United States of America
| | - Jeremiah K. Britt
- The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa, United States of America
| | - John A. Wemmie
- The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Graduate Program of Neuroscience, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa, United States of America
| | - Danielle S. Rudd
- The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Program in Genetics, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa, United States of America
| | - Thomas Wassink
- The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa, United States of America
| | - Hatem El-Shanti
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
- Shafallah Medical Genetics Center, Doha, Qatar
| | - Heather C. Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - Gemma L. Carvill
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - J. Robert Manak
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Program in Genetics, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Graduate Program in Molecular and Cellular Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Alexander G. Bassuk
- The University of Iowa, Iowa City, Iowa, United States of America
- Department of Pediatrics, The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Program in Genetics, The University of Iowa, Iowa City, Iowa, United States of America
- Department of Neurology, The University of Iowa, Iowa City, Iowa, United States of America
- Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Graduate Program in Molecular and Cellular Biology, The University of Iowa, Iowa City, Iowa, United States of America
| |
Collapse
|
23
|
McFadden K, Minshew NJ. Evidence for dysregulation of axonal growth and guidance in the etiology of ASD. Front Hum Neurosci 2013; 7:671. [PMID: 24155705 PMCID: PMC3804918 DOI: 10.3389/fnhum.2013.00671] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Accepted: 09/26/2013] [Indexed: 12/24/2022] Open
Abstract
Current theories concerning the cause of autism spectrum disorders (ASDs) have converged on the concept of abnormal development of brain connectivity. This concept is supported by accumulating evidence from functional imaging, diffusion tensor imaging, and high definition fiber tracking studies which suggest altered microstructure in the axonal tracts connecting cortical areas may underly many of the cognitive manifestations of ASD. Additionally, large-scale genomic studies implicate numerous gene candidates known or suspected to mediate neuritic outgrowth and axonal guidance in fetal and perinatal life. Neuropathological observations in postmortem ASD brain samples further support this model and include subtle disturbances of cortical lamination and subcortical axonal morphology. Of note is the relatively common finding of poor differentiation of the gray–white junction associated with an excess superficial white matter or “interstitial” neurons (INs). INs are thought to be remnants of the fetal subplate, a transient structure which plays a key role in the guidance and morphogenesis of thalamocortical and cortico-cortical connections and the organization of cortical columnar architecture. While not discounting the importance of synaptic dysfunction in the etiology of ASD, this paper will briefly review the cortical abnormalities and genetic evidence supporting a model of dysregulated axonal growth and guidance as key developmental processes underlying the clinical manifestations of ASD.
Collapse
Affiliation(s)
- Kathryn McFadden
- Department of Neurobiology, University of Pittsburgh Pittsburgh, PA, USA
| | | |
Collapse
|
24
|
Zhang J, Dennis KA, Darling RD, Alzghoul L, Paul IA, Simpson KL, Lin RCS. Neonatal citalopram exposure decreases serotonergic fiber density in the olfactory bulb of male but not female adult rats. Front Cell Neurosci 2013; 7:67. [PMID: 23675318 PMCID: PMC3650517 DOI: 10.3389/fncel.2013.00067] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 04/22/2013] [Indexed: 12/26/2022] Open
Abstract
Manipulation of serotonin (5HT) during early development has been shown to induce long-lasting morphological changes within the raphe nuclear complex and serotonergic circuitry throughout the brain. Recent studies have demonstrated altered raphe-derived 5HT transporter (SERT) immunoreactive axonal expression in several cortical target sites after brief perinatal exposure to selective 5HT reuptake inhibitors such as citalopram (CTM). Since the serotonergic raphe nuclear complex projects to the olfactory bulb (OB) and perinatal 5HT disruption has been shown to disrupt olfactory behaviors, the goal of this study was to further investigate such developmental effects in the OB of CTM exposed animals. Male and female rat pups were exposed to CTM from postnatal day 8–21. After animals reach adulthood (>90 days), OB tissue sections were processed immunohistochemically for SERT antiserum. Our data revealed that the density of the SERT immunoreactive fibers decreased ~40% in the OB of CTM exposed male rats, but not female rats. Our findings support a broad and long-lasting change throughout most of the 5HT system, including the OB, after early manipulation of 5HT. Because dysfunction of the early 5HT system has been implicated in the etiology of neurodevelopmental disorders such as autism spectrum disorders (ASDs), these new findings may offer insight into the abnormal olfactory perception often noted in patients with ASD.
Collapse
Affiliation(s)
- Junlin Zhang
- Department of Neurobiology and Anatomical Sciences, The University of Mississippi Medical Center Jackson, MS, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Sato K. Placenta-derived hypo-serotonin situations in the developing forebrain cause autism. Med Hypotheses 2013; 80:368-72. [PMID: 23375670 DOI: 10.1016/j.mehy.2013.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 11/13/2012] [Accepted: 01/03/2013] [Indexed: 11/16/2022]
Abstract
Autism is a pervasive developmental disorder that is characterized by the behavioral traits of impaired social cognition and communication, and repetitive and/or obsessive behavior and interests. Although there are many theories and speculations about the pathogenetic causes of autism, the disruption of the serotonergic system is one of the most consistent and well-replicated findings. Recently, it has been reported that placenta-derived serotonin is the main source in embryonic day (E) 10-15 mouse forebrain, after that period, the serotonergic fibers start to supply serotonin into the forebrain. E 10-15 is the very important developing period, when cortical neurogenesis, migration and initial axon targeting are processed. Since all these events have been considered to be involved in the pathogenesis of autism and they are highly controlled by serotonin signals, the paucity of placenta-derived serotonin should have potential importance when the pathogenesis of autism is considered. I, thus, postulate a hypothesis that placenta-derived hypo-serotonin situations in the developing forebrain cause autism. The hypothesis is as follows. Various factors, such as inflammation, dysfunction of the placenta, together with genetic predispositions cause a decrease of placenta-derived serotonin levels. The decrease of placenta-derived serotonin levels leads to hypo-serotonergic situations in the forebrain of the fetus. The paucity of serotonin in the forebrain leads to mis-wiring in important regions which are responsible for the theory of mind. The paucity of serotonin in the forebrain also causes over-growth of serotonergic fibers. These disturbances result in network deficiency and aberration of the serotonergic system, leading to the autistic phenotypes.
Collapse
Affiliation(s)
- Kohji Sato
- Department of Anatomy & Neuroscience, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashiku, Hamamatsu, Shizuoka 431-3192, Japan.
| |
Collapse
|
26
|
Blatt GJ. The neuropathology of autism. SCIENTIFICA 2012; 2012:703675. [PMID: 24278731 PMCID: PMC3820437 DOI: 10.6064/2012/703675] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/07/2012] [Indexed: 06/02/2023]
Abstract
Autism is a behaviorally defined neurodevelopmental disorder that affects over 1% of new births in the United States and about 2% of boys. The etiologies are unknown and they are genetically complex. There may be epigenetic effects, environmental influences, and other factors that contribute to the mechanisms and affected neural pathway(s). The underlying neuropathology of the disorder has been evolving in the literature to include specific brain areas in the cerebellum, limbic system, and cortex. Part(s) of structures appear to be affected most rather than the entire structure, for example, select nuclei of the amygdala, the fusiform face area, and so forth. Altered cortical organization characterized by more frequent and narrower minicolumns and early overgrowth of the frontal portion of the brain, affects connectivity. Abnormalities include cytoarchitectonic laminar differences, excess white matter neurons, decreased numbers of GABAergic cerebellar Purkinje cells, and other events that can be traced developmentally and cause anomalies in circuitry. Problems with neurotransmission are evident by recent receptor and binding site studies especially in the inhibitory GABA system likely contributing to an imbalance of excitatory/inhibitory transmission. As postmortem findings are related to core behavior symptoms, and technology improves, researchers are gaining a much better perspective of contributing factors to the disorder.
Collapse
Affiliation(s)
- Gene J. Blatt
- Department of Anatomy & Neurobiology, School of Medicine, Boston University, 72 East Concord Street L 1004, Boston, MA 02118, USA
| |
Collapse
|
27
|
El-Ansary AK, Bacha AB, Kotb M. Etiology of autistic features: the persisting neurotoxic effects of propionic acid. J Neuroinflammation 2012; 9:74. [PMID: 22531301 PMCID: PMC3425128 DOI: 10.1186/1742-2094-9-74] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 02/13/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent clinical observations suggest that certain gut and dietary factors may transiently worsen symptoms in autism. Propionic acid (PA) is a short chain fatty acid and an important intermediate of cellular metabolism. Although PA has several beneficial biological effects, its accumulation is neurotoxic. METHODS Two groups of young Western albino male rats weighing about 45 to 60 grams (approximately 21 days old) were used in the present study. The first group consisted of oral buffered PA-treated rats that were given a neurotoxic dose of 250 mg/kg body weight/day for three days, n = eight; the second group of rats were given only phosphate buffered saline and used as a control. Biochemical parameters representing oxidative stress, energy metabolism, neuroinflammation, neurotransmission, and apoptosis were investigated in brain homogenates of both groups. RESULTS Biochemical analyses of brain homogenates from PA-treated rats showed an increase in oxidative stress markers (for example, lipid peroxidation), coupled with a decrease in glutathione (GSH) and glutathione peroxidase (GPX) and catalase activities. Impaired energy metabolism was ascertained through the decrease of lactate dehydrogenase and activation of creatine kinase (CK). Elevated IL-6, TNFα, IFNγ and heat shock protein 70 (HSP70) confirmed the neuroinflammatory effect of PA. Moreover, elevation of caspase3 and DNA fragmentation proved the pro-apoptotic and neurotoxic effect of PA to rat pups CONCLUSION By comparing the results obtained with those from animal models of autism or with clinical data on the biochemical profile of autistic patients, this study showed that the neurotoxicity of PA as an environmental factor could play a central role in the etiology of autistic biochemical features.
Collapse
Affiliation(s)
- Afaf K El-Ansary
- Biochemistry Department, Science College, King Saud University, Riyadh, Saudi Arabia
| | - Abir Ben Bacha
- Biochemistry Department, Science College, King Saud University, Riyadh, Saudi Arabia
| | - Malak Kotb
- Department of Molecular Genetics, Biochemistry and Microbiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| |
Collapse
|
28
|
Pascual JM. Animal models of the human mind: is there anything like being autistic? Neurosci Lett 2011; 505:59-60. [PMID: 22005577 DOI: 10.1016/j.neulet.2011.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Juan M Pascual
- Rare Brain Disorders Clinic and Laboratory, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
| |
Collapse
|