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Ooi QY, Qin X, Yuan Y, Zhang X, Yao Y, Hao H, Li L. Alteration of Excitation/Inhibition Imbalance in the Hippocampus and Amygdala of Drug-Resistant Epilepsy Patients Treated with Acute Vagus Nerve Stimulation. Brain Sci 2023; 13:976. [PMID: 37508908 PMCID: PMC10377456 DOI: 10.3390/brainsci13070976] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/09/2023] [Accepted: 06/16/2023] [Indexed: 07/30/2023] Open
Abstract
An imbalance between excitation (E) and inhibition (I) in the brain has been identified as a key pathophysiology of epilepsy over the years. The hippocampus and amygdala in the limbic system play a crucial role in the initiation and conduction of epileptic seizures and are often referred to as the transfer station and amplifier of seizure activities. Existing animal and imaging studies reveal that the hippocampus and amygdala, which are significant parts of the vagal afferent network, can be modulated in order to generate an antiepileptic effect. Using stereo-electroencephalography (SEEG) data, we examined the E/I imbalance in the hippocampus and amygdala of ten drug-resistant epilepsy children treated with acute vagus nerve stimulation (VNS) by estimating the 1/f power slope of hippocampal and amygdala signals in the range of 1-80 Hz. While the change in the 1/f power slope from VNS-BASE varied between different stimulation amplitudes and brain regions, it was more prominent in the hippocampal region. In the hippocampal region, we found a flatter 1/f power slope during VNS-ON in patients with good responsiveness to VNS under the optimal stimulation amplitude, indicating that the E/I imbalance in the region was improved. There was no obvious change in 1/f power slope for VNS poor responders. For VNS non-responders, the 1/f power slope slightly increased when the stimulation was applied. Overall, this study implies that the regulation of E/I imbalance in the epileptic brain, especially in the hippocampal region, may be an acute intracranial effect of VNS.
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Affiliation(s)
- Qian Yi Ooi
- National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
| | - Xiaoya Qin
- National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
- Precision Medicine and Healthcare Research Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518071, China
| | - Yuan Yuan
- National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
- Precision Medicine and Healthcare Research Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518071, China
| | - Xiaobin Zhang
- Department of Functional Neurosurgery, Xiamen Humanity Hospital, Fujian Medical University, Fuzhou 350005, China
| | - Yi Yao
- Department of Functional Neurosurgery, Xiamen Humanity Hospital, Fujian Medical University, Fuzhou 350005, China
- Surgery Division, Epilepsy Center, Shenzhen Children's Hospital, Shenzhen 518038, China
| | - Hongwei Hao
- National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
| | - Luming Li
- National Engineering Research Center of Neuromodulation, School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
- Precision Medicine and Healthcare Research Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518071, China
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
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Coskunpinar EM, Tur S, Cevher Binici N, Yazan Songür C. Association of GABRG3, GABRB3, HTR2A Gene Variants with Autism Spectrum Disorder. Gene 2023; 870:147399. [PMID: 37019319 DOI: 10.1016/j.gene.2023.147399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 03/18/2023] [Accepted: 03/22/2023] [Indexed: 04/05/2023]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental and neurobehavioral disorder characterized by impaired social communication, repetitive and restricted patterns of behavior, activity, or interest, and altered emotional processing. Reported prevalence is 4 times higher in men and it has increased in recent years. Immunological, environmental, epigenetic, and genetic factors play a role in the pathophysiology of autism. Many neurochemical pathways and neuroanatomical events are effective in determining the disease. It is still unclear how the main symptoms of autism occur because of this complex and heterogeneous situation. In this study, we focused on gamma amino butyric acid (GABA) and serotonin, which are thought to contribute to the etiology of autism; it is aimed to elucidate the mechanism of the disease by investigating variant changes in the GABA receptor subunit genes GABRB3, GABRG3 and the HTR2A gene, which encodes one of the serotonin receptors. 200 patients with ASD between the ages of 3-9 and 100 healthy volunteers were included in the study. Genomic DNA isolation was performed from peripheral blood samples taken from volunteers. Genotyping was performed using the RFLP method with PCR specific for specific variants. Data were analyzed with SPSS v25.0 program. According to the data obtained in our study; In terms of HTR2A (rs6313 T102C) genotypes, the homozygous C genotype carrying frequency in the patient group and the homozygous T genotype carrying frequency in the GABRG3 (rs140679 C/T) genotypes were found to be significantly higher in the patient group compared to the control group (*p: 0.0001, p: 0.0001). It was determined that the frequency of individuals with homozygous genotype was significantly higher in the patient group compared to the control group and having homozygous genotypes increased the disease risk approximately 1.8 times. In terms of GABRB3 (rs2081648 T/C) genotypes, it was determined that there was no statistically significant difference in the frequency of carrying homozygous C genotype in the patient group compared to the control group (p: 0.36). According to the results of our study, we think that the HTR2A (rs6313 T102C) polymorphism is effective in modulating the empathic and autistic characteristics of individuals, and that the HTR2A (rs6313 T102C) polymorphism is more distributed in the post-synaptic membranes in individuals with a higher number of C alleles. We believe that this situation can be attributed to the spontaneous stimulatory distribution of the HTR2A gene in the postsynaptic membranes because of T102C transformation. In genetically based autism cases, carrying the point mutation in the rs6313 variant of the HTR2A gene and the C allele and the point mutation in the rs140679 variant of the GABRG3 gene and accordingly carrying the T allele provide a predisposition to the disease.
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Affiliation(s)
- Ender M Coskunpinar
- Department of Medical Biology, School of Medicine, University of Health Sciences, Turkey.
| | - Seymanur Tur
- Department of Medical Biology, School of Medicine, University of Health Sciences, Turkey.
| | - Nagihan Cevher Binici
- Department of Child and Adolescent Psychiatry, University of Health Sciences Dr. Behcet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Izmir, Turkey.
| | - Cisel Yazan Songür
- Department of Child and Adolescent Psychiatry, University of Health Sciences Dr. Behcet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Izmir, Turkey.
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Tallarico M, Leo A, Russo E, Citraro R, Palma E, De Sarro G. Seizure susceptibility to various convulsant stimuli in the BTBR mouse model of autism spectrum disorders. Front Pharmacol 2023; 14:1155729. [PMID: 37153775 PMCID: PMC10157402 DOI: 10.3389/fphar.2023.1155729] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/07/2023] [Indexed: 05/10/2023] Open
Abstract
Background: Autism spectrum disorders (ASDs) are one of the most severe chronic childhood disorders in terms of prevalence, morbidity, and impact on society. Interestingly, several systematic reviews and meta-analyses documented a bidirectional link between epilepsy and ASD, supporting the hypothesis that both disorders may have common neurobiological pathways. According to this hypothesis, an imbalance of the excitatory/inhibitory (E/I) ratio in several brain regions may represent a causal mechanism underpinning the co-occurrence of these neurological diseases. Methods: To investigate this bidirectional link, we first tested the seizure susceptibility to chemoconvulsants acting on GABAergic and glutamatergic systems in the BTBR mice, in which an imbalance between E/I has been previously demonstrated. Subsequently, we performed the PTZ kindling protocol to study the impact of seizures on autistic-like behavior and other neurological deficits in BTBR mice. Results: We found that BTBR mice have an increased susceptibility to seizures induced by chemoconvulsants impairing GABAA neurotransmission in comparison to C57BL/6J control mice, whereas no significant difference in seizure susceptibility was observed after administration of AMPA, NMDA, and Kainate. This data suggests that deficits in GABAergic neurotransmission can increase seizure susceptibility in this strain of mice. Interestingly, BTBR mice showed a longer latency in the development of kindling compared to control mice. Furthermore, PTZ-kindling did not influence autistic-like behavior in BTBR mice, whereas it was able to significantly increase anxiety and worsen cognitive performance in this strain of mice. Interestingly, C57BL/6J displayed reduced sociability after PTZ injections, supporting the hypothesis that a tight connection exists between ASD and epilepsy. Conclusion: BTBR mice can be considered a good model to study epilepsy and ASD contemporarily. However, future studies should shed light on the mechanisms underpinning the co-occurrence of these neurological disorders in the BTBR model.
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Affiliation(s)
- Martina Tallarico
- Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
| | - Antonio Leo
- Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
- System and Applied Pharmacology@University Magna Grecia, Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
- *Correspondence: Antonio Leo,
| | - Emilio Russo
- Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
| | - Rita Citraro
- Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
- System and Applied Pharmacology@University Magna Grecia, Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
| | - Ernesto Palma
- Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
| | - Giovambattista De Sarro
- Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
- System and Applied Pharmacology@University Magna Grecia, Science of Health Department, School of Medicine and Surgery, Magna Graecia University of Catanzaro, Catanzaro, Italy
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From bench to bedside: The mGluR5 system in people with and without Autism Spectrum Disorder and animal model systems. Transl Psychiatry 2022; 12:395. [PMID: 36127322 PMCID: PMC9489881 DOI: 10.1038/s41398-022-02143-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 08/19/2022] [Accepted: 09/01/2022] [Indexed: 11/08/2022] Open
Abstract
The metabotropic glutamate receptor 5 (mGluR5) is a key regulator of excitatory (E) glutamate and inhibitory (I) γ-amino butyric acid (GABA) signalling in the brain. Despite the close functional ties between mGluR5 and E/I signalling, no-one has directly examined the relationship between mGluR5 and glutamate or GABA in vivo in the human brain of autistic individuals. We measured [18F] FPEB (18F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile) binding in 15 adults (6 with Autism Spectrum Disorder) using two regions of interest, the left dorsomedial prefrontal cortex and a region primarily composed of left striatum and thalamus. These two regions were mapped out using MEGA-PRESS voxels and then superimposed on reconstructed PET images. This allowed for direct comparison between mGluR5, GABA + and Glx. To better understand the molecular underpinnings of our results we used an autoradiography study of mGluR5 in three mouse models associated with ASD: Cntnap2 knockout, Shank3 knockout, and 16p11.2 deletion. Autistic individuals had significantly higher [18F] FPEB binding (t (13) = -2.86, p = 0.047) in the left striatum/thalamus region of interest as compared to controls. Within this region, there was a strong negative correlation between GABA + and mGluR5 density across the entire cohort (Pearson's correlation: r (14) = -0.763, p = 0.002). Cntnap2 KO mice had significantly higher mGlu5 receptor binding in the striatum (caudate-putamen) as compared to wild-type (WT) mice (n = 15, p = 0.03). There were no differences in mGluR5 binding for mice with the Shank3 knockout or 16p11.2 deletion. Given that Cntnap2 is associated with a specific striatal deficit of parvalbumin positive GABA interneurons and 'autistic' features, our findings suggest that an increase in mGluR5 in ASD may relate to GABAergic interneuron abnormalities.
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Chakraborty S, Parayil R, Mishra S, Nongthomba U, Clement JP. Epilepsy Characteristics in Neurodevelopmental Disorders: Research from Patient Cohorts and Animal Models Focusing on Autism Spectrum Disorder. Int J Mol Sci 2022; 23:ijms231810807. [PMID: 36142719 PMCID: PMC9501968 DOI: 10.3390/ijms231810807] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Epilepsy, a heterogeneous group of brain-related diseases, has continued to significantly burden society and families. Epilepsy comorbid with neurodevelopmental disorders (NDDs) is believed to occur due to multifaceted pathophysiological mechanisms involving disruptions in the excitation and inhibition (E/I) balance impeding widespread functional neuronal circuitry. Although the field has received much attention from the scientific community recently, the research has not yet translated into actionable therapeutics to completely cure epilepsy, particularly those comorbid with NDDs. In this review, we sought to elucidate the basic causes underlying epilepsy as well as those contributing to the association of epilepsy with NDDs. Comprehensive emphasis is put on some key neurodevelopmental genes implicated in epilepsy, such as MeCP2, SYNGAP1, FMR1, SHANK1-3 and TSC1, along with a few others, and the main electrophysiological and behavioral deficits are highlighted. For these genes, the progress made in developing appropriate and valid rodent models to accelerate basic research is also detailed. Further, we discuss the recent development in the therapeutic management of epilepsy and provide a briefing on the challenges and caveats in identifying and testing species-specific epilepsy models.
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Affiliation(s)
- Sukanya Chakraborty
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Rrejusha Parayil
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Shefali Mishra
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - Upendra Nongthomba
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - James P. Clement
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
- Correspondence: ; Tel.: +91-08-2208-2613
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Möhrle D, Wang W, Whitehead SN, Schmid S. GABA B Receptor Agonist R-Baclofen Reverses Altered Auditory Reactivity and Filtering in the Cntnap2 Knock-Out Rat. Front Integr Neurosci 2021; 15:710593. [PMID: 34489651 PMCID: PMC8417788 DOI: 10.3389/fnint.2021.710593] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 07/27/2021] [Indexed: 12/23/2022] Open
Abstract
Altered sensory information processing, and auditory processing, in particular, is a common impairment in individuals with autism spectrum disorder (ASD). One prominent hypothesis for the etiology of ASD is an imbalance between neuronal excitation and inhibition. The selective GABAB receptor agonist R-Baclofen has been shown previously to improve social deficits and repetitive behaviors in several mouse models for neurodevelopmental disorders including ASD, and its formulation Arbaclofen has been shown to ameliorate social avoidance symptoms in some individuals with ASD. The present study investigated whether R-Baclofen can remediate ASD-related altered sensory processing reliant on excitation/inhibition imbalance in the auditory brainstem. To assess a possible excitation/inhibition imbalance in the startle-mediating brainstem underlying ASD-like auditory-evoked behaviors, we detected and quantified brain amino acid levels in the nucleus reticularis pontis caudalis (PnC) of rats with a homozygous loss-of-function mutation in the ASD-linked gene Contactin-associated protein-like 2 (Cntnap2) and their wildtype (WT) littermates using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS). Abnormal behavioral read-outs of brainstem auditory signaling in Cntnap2 KO rats were accompanied by increased levels of GABA, glutamate, and glutamine in the PnC. We then compared the effect of R-Baclofen on behavioral read-outs of brainstem auditory signaling in Cntnap2 KO and WT rats. Auditory reactivity, sensory filtering, and sensorimotor gating were tested in form of acoustic startle response input-output functions, short-term habituation, and prepulse inhibition before and after acute administration of R-Baclofen (0.75, 1.5, and 3 mg/kg). Systemic R-Baclofen treatment improved disruptions in sensory filtering in Cntnap2 KO rats and suppressed exaggerated auditory startle responses, in particular to moderately loud sounds. Lower ASR thresholds in Cntnap2 KO rats were increased in a dose-dependent fashion, with the two higher doses bringing thresholds close to controls, whereas shorter ASR peak latencies at the threshold were further exacerbated. Impaired prepulse inhibition increased across various acoustic prepulse conditions after administration of R-Baclofen in Cntnap2 KO rats, whereas R-Baclofen did not affect prepulse inhibition in WT rats. Our findings suggest that GABAB receptor agonists may be useful for pharmacologically targeting multiple aspects of sensory processing disruptions involving neuronal excitation/inhibition imbalances in ASD.
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Affiliation(s)
- Dorit Möhrle
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Wenxuan Wang
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Shawn N Whitehead
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Susanne Schmid
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
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7
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El-Ansary A, Chirumbolo S, Bhat RS, Dadar M, Ibrahim EM, Bjørklund G. The Role of Lipidomics in Autism Spectrum Disorder. Mol Diagn Ther 2021; 24:31-48. [PMID: 31691195 DOI: 10.1007/s40291-019-00430-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental syndrome commonly diagnosed in early childhood; it is usually characterized by impairment in reciprocal communication and speech, repetitive behaviors, and social withdrawal with loss in communication skills. Its development may be affected by a variety of environmental and genetic factors. Trained physicians diagnose and evaluate the severity of ASD based on clinical evaluations of observed behaviors. As such, this approach is inevitably dependent on the expertise and subjective assessment of those administering the clinical evaluations. There is a need to identify objective biological markers associated with diagnosis or clinical severity of the disorder. Several important issues and concerns exist regarding the diagnostic competence of the many abnormal plasma metabolites produced in the different biochemical pathways evaluated in individuals with ASD. The search for high-performing bio-analytes to diagnose and follow-up ASD development is still a major target in medicine. Dysregulation in the oxidative stress response and proinflammatory processes are major etiological causes of ASD pathogenesis. Furthermore, dicarboxylic acid metabolites, cholesterol-related metabolites, phospholipid-related metabolites, and lipid transporters and mediators are impaired in different pathological conditions that have a role in the ASD etiology. A mechanism may exist by which pro-oxidant environmental stressors and abnormal metabolites regulate clinical manifestations and development of ASD.
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Affiliation(s)
- Afaf El-Ansary
- Central Laboratory, Female Centre for Scientific and Medical Studies, King Saud University, Riyadh, Saudi Arabia.,Autism Research and Treatment Center, Riyadh, Saudi Arabia.,CONEM Saudi Autism Research Group, King Saud University, Riyadh, Saudi Arabia.,Therapeutic Chemistry Department, National Research Centre, Giza, Egypt
| | - Salvatore Chirumbolo
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,CONEM Scientific Secretary, Verona, Italy
| | - Ramesa Shafi Bhat
- Biochemistry Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Maryam Dadar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Eiman M Ibrahim
- Central Laboratory, Female Centre for Scientific and Medical Studies, King Saud University, Riyadh, Saudi Arabia
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine (CONEM), Toften 24, 8610, Mo i Rana, Norway.
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8
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Milovanovic M, Grujicic R. Electroencephalography in Assessment of Autism Spectrum Disorders: A Review. Front Psychiatry 2021; 12:686021. [PMID: 34658944 PMCID: PMC8511396 DOI: 10.3389/fpsyt.2021.686021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 08/30/2021] [Indexed: 01/01/2023] Open
Abstract
Electroencephalography (EEG) can further out our understanding of autistic spectrum disorders (ASD) neurophysiology. Epilepsy and ASD comorbidity range between 5 and 46%, but its temporal relationship, causal mechanisms and interplay with intellectual disability are still unknown. Epileptiform discharges with or without seizures go as high as 60%, and associate with epileptic encephalopathies, conceptual term suggesting that epileptic activity can lead to cognitive and behavioral impairment beyond the underlying pathology. Seizures and ASD may be the result of similar mechanisms, such as abnormalities in GABAergic fibers or GABA receptor function. Epilepsy and ASD are caused by a number of genetic disorders and variations that induce such dysregulation. Similarly, initial epilepsy may influence synaptic plasticity and cortical connection, predisposing a growing brain to cognitive delays and behavioral abnormalities. The quantitative EEG techniques could be a useful tool in detecting and possibly measuring dysfunctions in specific brain regions and neuronal regulation in ASD. Power spectra analysis reveals a U-shaped pattern of power abnormalities, with excess power in the low and high frequency bands. These might be the consequence of a complicated network of neurochemical changes affecting the inhibitory GABAergic interneurons and their regulation of excitatory activity in pyramidal cells. EEG coherence studies of functional connectivity found general local over-connectivity and long-range under-connectivity between different brain areas. GABAergic interneuron growth and connections are presumably impaired in the prefrontal and temporal cortices in ASD, which is important for excitatory/inhibitory balance. Recent advances in quantitative EEG data analysis and well-known epilepsy ASD co-morbidity consistently indicate a role of aberrant GABAergic transmission that has consequences on neuronal organization and connectivity especially in the frontal cortex.
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Affiliation(s)
- Maja Milovanovic
- Department for Epilepsy and Clinical Neurophysiology, Institute of Mental Health, Belgrade, Serbia.,Faculty for Special Education and Rehabilitation, University of Belgrade, Belgrade, Serbia
| | - Roberto Grujicic
- Clinical Department for Children and Adolescents, Institute of Mental Health, Belgrade, Serbia
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Port RG, Oberman LM, Roberts TPL. Revisiting the excitation/inhibition imbalance hypothesis of ASD through a clinical lens. Br J Radiol 2019; 92:20180944. [PMID: 31124710 PMCID: PMC6732925 DOI: 10.1259/bjr.20180944] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/19/2019] [Accepted: 05/21/2019] [Indexed: 12/22/2022] Open
Abstract
Autism spectrum disorder (ASD) currently affects 1 in 59 children, although the aetiology of this disorder remains unknown. Faced with multiple seemingly disparate and noncontiguous neurobiological alterations, Rubenstein and Merzenich hypothesized that imbalances between excitatory and inhibitory neurosignaling (E/I imbalance) underlie ASD. Since this initial statement, there has been a major focus examining this exact topic spanning both clinical and preclinical realms. The purpose of this article is to review the clinical neuroimaging literature surrounding E/I imbalance as an aetiology of ASD. Evidence for E/I imbalance is presented from several complementary clinical techniques including magnetic resonance spectroscopy, magnetoencephalography and transcranial magnetic stimulation. Additionally, two GABAergic potential interventions for ASD, which explicitly attempt to remediate E/I imbalance, are reviewed. The current literature suggests E/I imbalance as a useful framework for discussing the neurobiological etiology of ASD in at least a subset of affected individuals. While not constituting a completely unifying aetiology, E/I imbalance may be relevant as one of several underlying neuropathophysiologies that differentially affect individuals with ASD. Such statements do not diminish the value of the E/I imbalance concept-instead they suggest a possible role for the characterization of E/I imbalance, as well as other underlying neuropathophysiologies, in the biologically-based subtyping of individuals with ASD for potential applications including clinical trial enrichment as well as treatment triage.
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Affiliation(s)
| | - Lindsay M Oberman
- Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation for the Advancement of Military Medicine, Rockville, Maryland
| | - Timothy PL Roberts
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children’s Hospital of Philadelphia, Pennsylvania
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10
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Zoicas I, Kornhuber J. The Role of Metabotropic Glutamate Receptors in Social Behavior in Rodents. Int J Mol Sci 2019; 20:ijms20061412. [PMID: 30897826 PMCID: PMC6470515 DOI: 10.3390/ijms20061412] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/15/2019] [Accepted: 03/20/2019] [Indexed: 01/04/2023] Open
Abstract
The appropriate display of social behavior is critical for the well-being and survival of an individual. In many psychiatric disorders, including social anxiety disorder, autism spectrum disorders, depression and schizophrenia social behavior is severely impaired. Selective targeting of metabotropic glutamate receptors (mGluRs) has emerged as a novel treatment strategy for these disorders. In this review, we describe some of the behavioral paradigms used to assess different types of social behavior, such as social interaction, social memory, aggressive behavior and sexual behavior. We then focus on the effects of pharmacological modulation of mGluR1-8 on these types of social behavior. Indeed, accumulating evidence indicates beneficial effects of selective ligands of specific mGluRs in ameliorating innate or pharmacologically-induced deficits in social interaction and social memory as well as in reducing aggression in rodents. We emphasize the importance of future studies investigating the role of selective mGluR ligands on different types of social behavior to provide a better understanding of the neural mechanisms involved which, in turn, might promote the development of selective mGluR-targeted tools for the improved treatment of psychiatric disorders associated with social deficits.
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Affiliation(s)
- Iulia Zoicas
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91054, Germany.
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91054, Germany.
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Sathappan AV, Luber BM, Lisanby SH. The Dynamic Duo: Combining noninvasive brain stimulation with cognitive interventions. Prog Neuropsychopharmacol Biol Psychiatry 2019; 89:347-360. [PMID: 30312634 DOI: 10.1016/j.pnpbp.2018.10.006] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 12/21/2022]
Abstract
Pharmacotherapy, psychotherapy, and non-invasive brain stimulation (NIBS)1 each show efficacy in the treatment of psychiatric disorders; however, more efficacious interventions are needed as reflected by an overall unmet need in mental health care. While each modality has typically been studied and developed as a monotherapy, in practice they are typically used in combination. Research has begun to emerge studying the potential synergistic actions of multi-modal, combination therapies. For example, NIBS combined with rehabilitation strategies have demonstrated some success for speech and motor rehabilitation in stroke patients. In this review we present evidence suggesting that combining NIBS with targeted, cognitive interventions offers a potentially powerful new approach to treating neuropsychiatric disorders. Here we focus on NIBS studies using transcranial direct current stimulation (tDCS)2 and transcranial magnetic stimulation (TMS)3 given that these modalities are relatively safe, noninvasive, and can be performed simultaneously with neurocognitive interventions. We review the concept of "state dependent" effects of NIBS and highlight how simultaneous or sequential cognitive interventions could help optimize NIBS therapy by providing further control of ongoing neural activity in targeted neural networks. This review spans a range of neuropsychiatric disorders including major depressive disorder, schizophrenia, generalized anxiety, and autism. For each disorder, we emphasize neuroanatomical circuitry that could be engaged with combination therapy and critically discuss the literature that has begun to emerge. Finally, we present possible underlying mechanisms and propose future research strategies that may further refine the potential of combination therapies.
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Affiliation(s)
- Aakash V Sathappan
- Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Bruce M Luber
- Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Sarah H Lisanby
- Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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12
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Drozd HP, Karathanasis SF, Molosh AI, Lukkes JL, Clapp DW, Shekhar A. From bedside to bench and back: Translating ASD models. PROGRESS IN BRAIN RESEARCH 2018; 241:113-158. [PMID: 30447753 DOI: 10.1016/bs.pbr.2018.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Autism spectrum disorders (ASD) represent a heterogeneous group of disorders defined by deficits in social interaction/communication and restricted interests, behaviors, or activities. Models of ASD, developed based on clinical data and observations, are used in basic science, the "bench," to better understand the pathophysiology of ASD and provide therapeutic options for patients in the clinic, the "bedside." Translational medicine creates a bridge between the bench and bedside that allows for clinical and basic science discoveries to challenge one another to improve the opportunities to bring novel therapies to patients. From the clinical side, biomarker work is expanding our understanding of possible mechanisms of ASD through measures of behavior, genetics, imaging modalities, and serum markers. These biomarkers could help to subclassify patients with ASD in order to better target treatments to a more homogeneous groups of patients most likely to respond to a candidate therapy. In turn, basic science has been responding to developments in clinical evaluation by improving bench models to mechanistically and phenotypically recapitulate the ASD phenotypes observed in clinic. While genetic models are identifying novel therapeutics targets at the bench, the clinical efforts are making progress by defining better outcome measures that are most representative of meaningful patient responses. In this review, we discuss some of these challenges in translational research in ASD and strategies for the bench and bedside to bridge the gap to achieve better benefits to patients.
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Affiliation(s)
- Hayley P Drozd
- Program in Medical Neurobiology, Stark Neurosciences Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Sotirios F Karathanasis
- Program in Medical Neurobiology, Stark Neurosciences Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Andrei I Molosh
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Jodi L Lukkes
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - D Wade Clapp
- Department of Pediatrics, Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, United States; Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Anantha Shekhar
- Program in Medical Neurobiology, Stark Neurosciences Institute, Indiana University School of Medicine, Indianapolis, IN, United States; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States; Indiana Clinical and Translation Sciences Institute, Indiana University School of Medicine, Indianapolis, IN, United States.
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13
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El-Ansary A, Bacha AB, Bjørklund G, Al-Orf N, Bhat RS, Moubayed N, Abed K. Probiotic treatment reduces the autistic-like excitation/inhibition imbalance in juvenile hamsters induced by orally administered propionic acid and clindamycin. Metab Brain Dis 2018; 33:1155-1164. [PMID: 29582256 DOI: 10.1007/s11011-018-0212-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 02/27/2018] [Indexed: 12/15/2022]
Abstract
Increasing evidence suggests that the gut microbiota plays a key role in the central nervous system (CNS), and alterations of the gut microbiota composition due to environmental factors can contribute to neurodevelopmental disorders. Animal modeling may help to identify drugs that can normalize the altered gut microbiota and thereby ameliorate abnormal brain signaling pathways. The purpose of the present study was to investigate the therapeutic potency of probiotics such as Bifidobacteria and Lactobacilli on glutamate excitotoxicity as a neurotoxic effect induced by clindamycin and propionic acid (PPA) in juvenile hamsters. Fifty young golden Syrian hamsters weighing between 60 and 70 g were enrolled in the study. The hamsters were randomly divided into five groups, each with ten hamsters. The hamsters in the control group only received phosphate-buffered saline orally. The PPA-treated group received a neurotoxic dose of 250 mg PPA/kg body weight (BW)/day for three days. The clindamycin-treated group received 30 mg clindamycin/kg BW as a single orogastric dose on the day the experiment started. The two therapeutic groups received the same doses of PPA and clindamycin followed by 0.2 g probiotic/kg BW for three weeks. Biochemical parameters related to glutamate excitotoxicity were investigated in brain homogenates from each group of hamsters. Additionally, the development of pathogenic bacteria was monitored in stool samples from all groups. The microbiology results of the present study revealed descriptive changes in the fecal microbiota and the appearance of Clostridium species in the hamsters treated with clindamycin and PPA. Additionally, the effectiveness of the probiotic in the restoration of the normal gut microbiota was demonstrated. Moreover, clindamycin and PPA were found to induce a significant depletion of Mg2+ and γ-aminobutyric acid (GABA) and a remarkable increase in the Na+/Mg2+ and glutamate/GABA ratios but non-significant changes in the absolute levels of K+, Na+ and glutamate. The bacteria overgrowth induced by PPA and clindamycin in the present study effectively showed signs of neuronal toxicity. The study indicates that probiotics can be used safely to ameliorate glutamate excitotoxicity mostly through increasing depleted GABA and Mg2+ and decreasing the excitatory neurotransmitter, glutamate.
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Affiliation(s)
- Afaf El-Ansary
- Central Laboratory, Female Centre for Scientific and Medical Studies, King Saud University, Riyadh, Saudi Arabia
- Therapeutic Chemistry Department, National Research Centre, Dokki, Cairo, Egypt
| | - Abir Ben Bacha
- Biochemistry Department, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Toften 24, 8610, Mo i Rana, Norway.
| | - Nora Al-Orf
- Biochemistry Department, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Ramesa Shafi Bhat
- Biochemistry Department, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Nadine Moubayed
- Biology Department, College of Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Kawther Abed
- Biology Department, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
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14
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Frye RE. Social Skills Deficits in Autism Spectrum Disorder: Potential Biological Origins and Progress in Developing Therapeutic Agents. CNS Drugs 2018; 32:713-734. [PMID: 30105528 PMCID: PMC6105175 DOI: 10.1007/s40263-018-0556-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autism spectrum disorder is defined by two core symptoms: a deficit in social communication and the presence of repetitive behaviors and/or restricted interests. Currently, there is no US Food and Drug Administration-approved drug for these core symptoms. This article reviews the biological origins of the social function deficit associated with autism spectrum disorder and the drug therapies with the potential to treat this deficit. A review of the history of autism demonstrates that a deficit in social interaction has been the defining feature of the concept of autism from its conception. Abnormalities identified in early social skill development and an overview of the pathophysiology abnormalities associated with autism spectrum disorder are discussed as are the abnormalities in brain circuits associated with the social function deficit. Previous and ongoing clinical trials examining agents that have the potential to improve social deficits associated with autism spectrum disorder are discussed in detail. This discussion reveals that agents such as oxytocin and propranolol are particularly promising and undergoing active investigation, while other agents such as vasopressin agonists and antagonists are being activity investigated but have limited published evidence at this time. In addition, agents such as bumetanide and manipulation of the enteric microbiome using microbiota transfer therapy appear to have promising effects on core autism spectrum disorder symptoms including social function. Other pertinent issues associated with developing treatments in autism spectrum disorder, such as disease heterogeneity, high placebo response rates, trial design, and the most appropriate way of assessing effects on social skills (outcome measures), are also discussed.
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Affiliation(s)
- Richard E Frye
- Division of Neurodevelopmental Disorders, Department of Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, 1919 E Thomas St, Phoenix, AZ, 85016, USA.
- Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, 85004, USA.
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15
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Kirkovski M, Suo C, Enticott PG, Yücel M, Fitzgerald PB. Short communication: Sex-linked differences in gamma-aminobutyric acid (GABA) are related to social functioning in autism spectrum disorder. Psychiatry Res Neuroimaging 2018; 274:19-22. [PMID: 29500101 DOI: 10.1016/j.pscychresns.2018.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 01/22/2018] [Accepted: 02/09/2018] [Indexed: 01/08/2023]
Abstract
Magnetic resonance spectroscopy (MRS) was utilized to investigate sex differences in gamma-aminobutyric acid (GABA) between adults with autism spectrum disorder (ASD) and neurotypical (NT) controls. GABA at the right superior temporal sulcus (STS) is reported for 12 ASD and 14 NT participants. The results show no group differences in GABA. There was, however, a significant positive association between GABA at the STS and autism-related social impairments in females with ASD. These findings provide preliminary support for sex differences in GABAergic distribution and processes that contribute to social functioning in ASD.
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Affiliation(s)
- Melissa Kirkovski
- Deakin Child Study Centre, School of Psychology, Deakin University, Geelong, Australia; Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Clayton, Australia.
| | - Chao Suo
- Brain & Mental Health Laboratory, Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Victoria, Australia
| | - Peter Gregory Enticott
- Deakin Child Study Centre, School of Psychology, Deakin University, Geelong, Australia; Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Clayton, Australia
| | - Murat Yücel
- Brain & Mental Health Laboratory, Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Victoria, Australia
| | - Paul Bernard Fitzgerald
- Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Clayton, Australia
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16
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Tang ZQ, Lu Y. Anatomy and Physiology of Metabotropic Glutamate Receptors in Mammalian and Avian Auditory System. ACTA ACUST UNITED AC 2018; 1. [PMID: 30854519 DOI: 10.24966/tap-7752/100001] [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] [Indexed: 11/04/2022]
Abstract
Glutamate, as the major excitatory neurotransmitter used in the vertebrate brain, activates ionotropic and metabotropic glutamate receptors (iGluRs and mGluRs), which mediate fast and slow neuronal actions, respectively. mGluRs play important modulatory roles in many brain areas, forming potential targets for drugs developed to treat brain disorders. Here, we review studies on mGluRs in the mammalian and avian auditory system. Although anatomical expression of mGluRs in the cochlear nucleus has been well characterized, data for other auditory nuclei await more systematic investigations especially at the electron microscopy level. The physiology of mGluRs has been extensively studied using in vitro brain slice preparations, with a focus on the auditory circuitry in the brainstem. These in vitro physiological studies have demonstrated that mGluRs participate in synaptic transmission, regulate ionic homeostasis, induce synaptic plasticity, and maintain the balance between Excitation and Inhibition (E/I) in a variety of auditory structures. However, the modulatory roles of mGluRs in auditory processing remain largely unclear at the system and behavioral levels, and the functions of mGluRs in auditory disorders remain entirely unknown.
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Affiliation(s)
- Zheng-Quan Tang
- Oregon Hearing Research Center, Vollum Institute, Oregon Health and Science University, Oregon, USA
| | - Yong Lu
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Ohio, USA
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17
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Bozzi Y, Provenzano G, Casarosa S. Neurobiological bases of autism-epilepsy comorbidity: a focus on excitation/inhibition imbalance. Eur J Neurosci 2017; 47:534-548. [PMID: 28452083 DOI: 10.1111/ejn.13595] [Citation(s) in RCA: 161] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/18/2017] [Accepted: 04/21/2017] [Indexed: 12/13/2022]
Abstract
Autism spectrum disorders (ASD) and epilepsy are common neurological diseases of childhood, with an estimated incidence of approximately 0.5-1% of the worldwide population. Several genetic, neuroimaging and neuropathological studies clearly showed that both ASD and epilepsy have developmental origins and a substantial degree of heritability. Most importantly, ASD and epilepsy frequently coexist in the same individual, suggesting a common neurodevelopmental basis for these disorders. Genome-wide association studies recently allowed for the identification of a substantial number of genes involved in ASD and epilepsy, some of which are mutated in syndromes presenting both ASD and epilepsy clinical features. At the cellular level, both preclinical and clinical studies indicate that the different genetic causes of ASD and epilepsy may converge to perturb the excitation/inhibition (E/I) balance, due to the dysfunction of excitatory and inhibitory circuits in various brain regions. Metabolic and immune dysfunctions, as well as environmental causes also contribute to ASD pathogenesis. Thus, an E/I imbalance resulting from neurodevelopmental deficits of multiple origins might represent a common pathogenic mechanism for both diseases. Here, we will review the most significant studies supporting these hypotheses. A deeper understanding of the molecular and cellular determinants of autism-epilepsy comorbidity will pave the way to the development of novel therapeutic strategies.
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Affiliation(s)
- Yuri Bozzi
- Neurodevelopmental Disorders Research Group, Centre for Mind/Brain Sciences, University of Trento, via Sommarive 9, 38123, Povo, Trento, Italy.,CNR Neuroscience Institute, Pisa, Italy
| | - Giovanni Provenzano
- Laboratory of Molecular Neuropathology, Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Simona Casarosa
- CNR Neuroscience Institute, Pisa, Italy.,Laboratory of Neural Development and Regeneration, Centre for Integrative Biology, University of Trento, Trento, Italy
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18
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Epilepsy and intellectual disability linked protein Shrm4 interaction with GABA BRs shapes inhibitory neurotransmission. Nat Commun 2017; 8:14536. [PMID: 28262662 PMCID: PMC5343488 DOI: 10.1038/ncomms14536] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 01/09/2017] [Indexed: 02/07/2023] Open
Abstract
Shrm4, a protein expressed only in polarized tissues, is encoded by the KIAA1202 gene, whose mutations have been linked to epilepsy and intellectual disability. However, a physiological role for Shrm4 in the brain is yet to be established. Here, we report that Shrm4 is localized to synapses where it regulates dendritic spine morphology and interacts with the C terminus of GABAB receptors (GABABRs) to control their cell surface expression and intracellular trafficking via a dynein-dependent mechanism. Knockdown of Shrm4 in rat severely impairs GABABR activity causing increased anxiety-like behaviour and susceptibility to seizures. Moreover, Shrm4 influences hippocampal excitability by modulating tonic inhibition in dentate gyrus granule cells, in a process involving crosstalk between GABABRs and extrasynaptic δ-subunit-containing GABAARs. Our data highlights a role for Shrm4 in synaptogenesis and in maintaining GABABR-mediated inhibition, perturbation of which may be responsible for the involvement of Shrm4 in cognitive disorders and epilepsy. Mutations in the gene encoding Shrm4 are associated with epilepsy and intellectual disability. The authors show that Shrm4 interacts with GABAB receptors and regulates tonic inhibition in the hippocampus, and knockdown of Shrm4 in rats leads to anxiety-like behaviour and seizures.
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19
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Sivanesan S, Tan A, Jeyaraj R, Lam J, Gole M, Hardan A, Ashkan K, Rajadas J. Pharmaceuticals and Stem Cells in Autism Spectrum Disorders: Wishful Thinking? World Neurosurg 2017; 98:659-672. [DOI: 10.1016/j.wneu.2016.09.100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 09/24/2016] [Accepted: 09/26/2016] [Indexed: 12/21/2022]
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20
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Puig-Alcaraz C, Fuentes-Albero M, Cauli O. Relationship between adipic acid concentration and the core symptoms of autism spectrum disorders. Psychiatry Res 2016; 242:39-45. [PMID: 27259135 DOI: 10.1016/j.psychres.2016.05.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/20/2016] [Accepted: 05/20/2016] [Indexed: 11/27/2022]
Abstract
Dicarboxylic acids are an important source of information about metabolism and potential physiopathological alterations in children with autism spectrum disorders (ASDs). We measured the concentration between dicarboxylic adipic and suberic acids in children with an ASD and typically-developing (TD) children and analyzed any relationships between the severity of the core symptoms of ASDs and other clinical features (drugs, supplements, drugs, or diet). The core symptoms of autism were evaluated using the DSM-IV criteria, and adipic acid and suberic acid were measured in urine samples. Overall, no increase in the concentration of adipic acid in children with ASDs compared to TD children, however when considering vitamin B supplementation in ASD there were significantly increased level of urinary adipic acid in children with an ASD not taking vitamin B supplementation compared to supplemented children or to TD children. No significant difference were observed in suberic acid. Interestingly, the increase in adipic acid concentration was significantly and indirectly correlated with the severity of the deficit in socialization and communication skills in children with an ASD. Therefore, therapeutic treatments aimed at decreasing adipic acid concentration might not be beneficial for treating the core symptoms of ASDs.
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Affiliation(s)
- Carmen Puig-Alcaraz
- Area of Mental Health and Psychiatry, Hospital of Sagunto, Sagunto, Valencia, Spain; Departamento de Medicina y Cirugía, Facultad de Ciencias de la Salud, Universidad Cardenal Herrera-CEU, Castellón de la Plana, 12006 Castellón, Spain
| | | | - Omar Cauli
- Department of Nursing, University of Valencia, Valencia, Spain.
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21
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Frye RE, Rossignol DA. Identification and Treatment of Pathophysiological Comorbidities of Autism Spectrum Disorder to Achieve Optimal Outcomes. CLINICAL MEDICINE INSIGHTS-PEDIATRICS 2016; 10:43-56. [PMID: 27330338 PMCID: PMC4910649 DOI: 10.4137/cmped.s38337] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/15/2016] [Accepted: 05/18/2016] [Indexed: 02/06/2023]
Abstract
Despite the fact that the prevalence of autism spectrum disorder (ASD) continues to rise, no effective medical treatments have become standard of care. In this paper we review some of the pathophysiological abnormalities associated with ASD and their potential associated treatments. Overall, there is evidence for some children with ASD being affected by seizure and epilepsy, neurotransmitter dysfunction, sleep disorders, metabolic abnormalities, including abnormalities in folate, cobalamin, tetrahydrobiopterin, carnitine, redox and mitochondrial metabolism, and immune and gastrointestinal disorders. Although evidence for an association between these pathophysiological abnormalities and ASD exists, the exact relationship to the etiology of ASD and its associated symptoms remains to be further defined in many cases. Despite these limitations, treatments targeting some of these pathophysiological abnormalities have been studied in some cases with high-quality studies, whereas treatments for other pathophysiological abnormalities have not been well studied in many cases. There are some areas of more promising treatments specific for ASD including neurotransmitter abnormalities, particularly imbalances in glutamate and acetylcholine, sleep onset disorder (with behavioral therapy and melatonin), and metabolic abnormalities in folate, cobalamin, tetrahydrobiopterin, carnitine, and redox pathways. There is some evidence for treatments of epilepsy and seizures, mitochondrial and immune disorders, and gastrointestinal abnormalities, particularly imbalances in the enteric microbiome, but further clinical studies are needed in these areas to better define treatments specific to children with ASD. Clearly, there are some promising areas of ASD research that could lead to novel treatments that could become standard of care in the future, but more research is needed to better define subgroups of children with ASD who are affected by specific pathophysiological abnormalities and the optimal treatments for these abnormalities.
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Affiliation(s)
- Richard E Frye
- Arkansas Children's Research Institute, Little Rock, AR, USA.; Division of Neurology, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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22
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Wang Y, Billon C, Walker JK, Burris TP. Therapeutic Effect of a Synthetic RORα/γ Agonist in an Animal Model of Autism. ACS Chem Neurosci 2016; 7:143-8. [PMID: 26625251 PMCID: PMC4759619 DOI: 10.1021/acschemneuro.5b00159] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
![]()
Autism is a developmental disorder
of the nervous system associated
with impaired social communication and interactions as well excessive
repetitive behaviors. There are no drug therapies that directly target
the pathology of this disease. The retinoic acid receptor-related
orphan receptor α (RORα) is a nuclear receptor that has
been demonstrated to have reduced expression in many individuals with
autism spectrum disorder (ASD). Several genes that have been shown
to be downregulated in individuals with ASD have also been identified
as putative RORα target genes. Utilizing a synthetic RORα/γ
agonist, SR1078, that we identified previously, we demonstrate that
treatment of BTBR mice (a model of autism) with SR1078 results in
reduced repetitive behavior. Furthermore, these mice display increased
expression of ASD-associated RORα target genes in both the brains
of the BTBR mice and in a human neuroblastoma cell line treated with
SR1078. These data suggest that pharmacological activation of RORα
may be a method for treatment of autism.
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Affiliation(s)
- Yongjun Wang
- Department of Pharmacology & Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Cyrielle Billon
- Department of Pharmacology & Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - John K. Walker
- Department of Pharmacology & Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Thomas P. Burris
- Department of Pharmacology & Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
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23
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Oberman LM, Rotenberg A, Pascual-Leone A. Use of transcranial magnetic stimulation in autism spectrum disorders. J Autism Dev Disord 2015; 45:524-36. [PMID: 24127165 DOI: 10.1007/s10803-013-1960-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The clinical, social and financial burden of autism spectrum disorder (ASD) is staggering. We urgently need valid and reliable biomarkers for diagnosis and effective treatments targeting the often debilitating symptoms. Transcranial magnetic stimulation (TMS) is beginning to be used by a number of centers worldwide and may represent a novel technique with both diagnostic and therapeutic potential. Here we critically review the current scientific evidence for the use of TMS in ASD. Though preliminary data suggests promise, there is simply not enough evidence yet to conclusively support the clinical widespread use of TMS in ASD, neither diagnostically nor therapeutically. Carefully designed and properly controlled clinical trials are warranted to evaluate the true potential of TMS in ASD.
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Affiliation(s)
- Lindsay M Oberman
- Berenson-Allen Center for Noninvasive Brain Stimulation, and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, KS 158, Boston, MA, 02215, USA
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GABAB Receptor Agonist R-Baclofen Reverses Social Deficits and Reduces Repetitive Behavior in Two Mouse Models of Autism. Neuropsychopharmacology 2015; 40:2228-39. [PMID: 25754761 PMCID: PMC4613612 DOI: 10.1038/npp.2015.66] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 02/28/2015] [Accepted: 03/03/2015] [Indexed: 12/19/2022]
Abstract
Autism spectrum disorder (ASD) is diagnosed by two core behavioral criteria, unusual reciprocal social interactions and communication, and stereotyped, repetitive behaviors with restricted interests. Excitatory/inhibitory imbalance is a prominent hypothesis for the etiology of autism. The selective GABAB receptor agonist R-baclofen previously reversed social deficits and reduced repetitive behaviors in a mouse model of Fragile X syndrome, and Arbaclofen improved some clinical symptoms in some Fragile X and ASD patients. To evaluate R-baclofen in a broader range of mouse models of ASD, we tested both the R-baclofen enantiomer and the less potent S-baclofen enantiomer in two inbred strains of mice that display low sociability and/or high repetitive or stereotyped behaviors. R-baclofen treatment reversed social approach deficits in BTBR T+ Itpr3tf/J (BTBR), reduced repetitive self-grooming and high marble burying scores in BTBR, and reduced stereotyped jumping in C58/J (C58), at nonsedating doses. S-baclofen produced minimal effects at the same doses. These findings encourage investigations of R-baclofen in other preclinical model systems. Additional clinical studies may be warranted to further evaluate the hypothesis that the GABAB receptor represents a promising pharmacological target for treating appropriately stratified subsets of individuals with ASD.
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25
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Scahill L, Sukhodolsky DG, Anderberg E, Dimitropoulos A, Dziura J, Aman MG, McCracken J, Tierney E, Hallett V, Katz K, Vitiello B, McDougle C. Sensitivity of the modified Children’s Yale–Brown Obsessive Compulsive Scale to detect change: Results from two multi-site trials. AUTISM : THE INTERNATIONAL JOURNAL OF RESEARCH AND PRACTICE 2015; 20:145-52. [DOI: 10.1177/1362361315574889] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Repetitive behavior is a core feature of autism spectrum disorder. We used 8-week data from two federally funded, multi-site, randomized trials with risperidone conducted by the Research Units on Pediatric Psychopharmacology Autism Network to evaluate the sensitivity of the Children’s Yale–Brown Obsessive Compulsive Scale modified for autism spectrum disorder to detect change with treatment. Study 1 included 52 subjects assigned to placebo and 49 subjects to risperidone under double-blind conditions. In Study 2, 49 subjects received risperidone only and 75 subjects received risperidone plus parent training. The combined sample consisted of 187 boys and 38 girls (aged 4–17 years). At the medication-free baseline, the internal consistency on the Children’s Yale–Brown Obsessive Compulsive Scale modified for autism spectrum disorder total score was excellent (Cronbach’s alpha = 0.84) and the mean scores were similar across the four groups. Compared to placebo in Study 1, all three active treatment groups showed significant improvement (effect sizes: 0.74–0.88). There were no differences between active treatment groups. These results indicate that the Children’s Yale–Brown Obsessive Compulsive Scale modified for autism spectrum disorder has acceptable test–retest as evidenced by the medium to high correlations in the placebo group and demonstrated sensitivity to change with treatment.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Benedetto Vitiello
- National Institute of Mental Health, Child and Adolescent Treatment and Preventive Interventions Research Branch, USA
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26
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Dillon J, Franks CJ, Murray C, Edwards RJ, Calahorro F, Ishihara T, Katsura I, Holden-Dye L, O'Connor V. Metabotropic Glutamate Receptors: MODULATORS OF CONTEXT-DEPENDENT FEEDING BEHAVIOUR IN C. ELEGANS. J Biol Chem 2015; 290:15052-65. [PMID: 25869139 DOI: 10.1074/jbc.m114.606608] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Indexed: 11/06/2022] Open
Abstract
Glutamatergic neurotransmission is evolutionarily conserved across animal phyla. A major class of glutamate receptors consists of the metabotropic glutamate receptors (mGluRs). In C. elegans, three mGluR genes, mgl-1, mgl-2, and mgl-3, are organized into three subgroups, similar to their mammalian counterparts. Cellular reporters identified expression of the mgls in the nervous system of C. elegans and overlapping expression in the pharyngeal microcircuit that controls pharyngeal muscle activity and feeding behavior. The overlapping expression of mgls within this circuit allowed the investigation of receptor signaling per se and in the context of receptor interactions within a neural network that regulates feeding. We utilized the pharmacological manipulation of neuronally regulated pumping of the pharyngeal muscle in the wild-type and mutants to investigate MGL function. This defined a net mgl-1-dependent inhibition of pharyngeal pumping that is modulated by mgl-3 excitation. Optogenetic activation of the pharyngeal glutamatergic inputs combined with electrophysiological recordings from the isolated pharyngeal preparations provided further evidence for a presynaptic mgl-1-dependent regulation of pharyngeal activity. Analysis of mgl-1, mgl-2, and mgl-3 mutant feeding behavior in the intact organism after acute food removal identified a significant role for mgl-1 in the regulation of an adaptive feeding response. Our data describe the molecular and cellular organization of mgl-1, mgl-2, and mgl-3. Pharmacological analysis identified that, in these paradigms, mgl-1 and mgl-3, but not mgl-2, can modulate the pharyngeal microcircuit. Behavioral analysis identified mgl-1 as a significant determinant of the glutamate-dependent modulation of feeding, further highlighting the significance of mGluRs in complex C. elegans behavior.
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Affiliation(s)
- James Dillon
- From the Centre for Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, United Kingdom,
| | - Christopher J Franks
- From the Centre for Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, United Kingdom
| | | | - Richard J Edwards
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales 2052, Australia
| | - Fernando Calahorro
- From the Centre for Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, United Kingdom
| | - Takeshi Ishihara
- the Department of Biology, Graduate School of Science, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan, and
| | - Isao Katsura
- the National Institute of Genetics, Yata 1111, Mishima, Shizuoka-ken, 411-8540, Japan
| | - Lindy Holden-Dye
- From the Centre for Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, United Kingdom
| | - Vincent O'Connor
- From the Centre for Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, United Kingdom,
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27
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Oberman LM, Enticott PG, Casanova MF, Rotenberg A, Pascual-Leone A, McCracken JT. Transcranial magnetic stimulation (TMS) therapy for autism: an international consensus conference held in conjunction with the international meeting for autism research on May 13th and 14th, 2014. Front Hum Neurosci 2015; 8:1034. [PMID: 25642178 PMCID: PMC4295436 DOI: 10.3389/fnhum.2014.01034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 12/09/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Lindsay M Oberman
- Neuroplasticity and Autism Spectrum Disorder Program, Department of Psychiatry and Human Behavior, E.P. Bradley Hospital and Warren Alpert Medical School, Brown University Providence, RI, USA
| | - Peter G Enticott
- Cognitive Neuroscience Unit, School of Psychology, Deakin University Burwood, VIC, Australia
| | - Manuel F Casanova
- Department of Psychiatry and Behavioral Science, University of Louisville Louisville, KY, USA
| | - Alexander Rotenberg
- Neuromodulation Program, Department of Neurology, Boston Children's Hospital and Harvard Medical School Boston, MA, USA ; Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, MA, USA
| | - Alvaro Pascual-Leone
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, MA, USA
| | - James T McCracken
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at University of California, Los Angeles Los Angeles, CA, USA
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28
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Lu Y. Metabotropic glutamate receptors in auditory processing. Neuroscience 2014; 274:429-45. [PMID: 24909898 PMCID: PMC5299851 DOI: 10.1016/j.neuroscience.2014.05.057] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/03/2014] [Accepted: 05/28/2014] [Indexed: 11/24/2022]
Abstract
As the major excitatory neurotransmitter used in the vertebrate brain, glutamate activates ionotropic and metabotropic glutamate receptors (mGluRs), which mediate fast and slow neuronal actions, respectively. Important modulatory roles of mGluRs have been shown in many brain areas, and drugs targeting mGluRs have been developed for the treatment of brain disorders. Here, I review studies on mGluRs in the auditory system. Anatomical expression of mGluRs in the cochlear nucleus has been well characterized, while data for other auditory nuclei await more systematic investigations at both the light and electron microscopy levels. The physiology of mGluRs has been extensively studied using in vitro brain slice preparations, with a focus on the lower auditory brainstem in both mammals and birds. These in vitro physiological studies have revealed that mGluRs participate in neurotransmission, regulate ionic homeostasis, induce synaptic plasticity, and maintain the balance between excitation and inhibition in a variety of auditory structures. However, very few in vivo physiological studies on mGluRs in auditory processing have been undertaken at the systems level. Many questions regarding the essential roles of mGluRs in auditory processing still remain unanswered and more rigorous basic research is warranted.
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Affiliation(s)
- Y Lu
- Department of Anatomy and Neurobiology, College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, USA.
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29
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The need for a comprehensive molecular characterization of autism spectrum disorders. Int J Neuropsychopharmacol 2014; 17:651-73. [PMID: 24229490 DOI: 10.1017/s146114571300117x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Autism spectrum disorders (ASD) are a heterogeneous group of disorders which have complex behavioural phenotypes. Although ASD is a highly heritable neuropsychiatric disorder, genetic research alone has not provided a profound understanding of the underlying causes. Recent developments using biochemical tools such as transcriptomics, proteomics and cellular models, will pave the way to gain new insights into the underlying pathological pathways. This review addresses the state-of-the-art in the search for molecular biomarkers for ASD. In particular, the most important findings in the biochemical field are highlighted and the need for establishing streamlined interaction between behavioural studies, genetics and proteomics is stressed. Eventually, these approaches will lead to suitable translational ASD models and, therefore, a better disease understanding which may facilitate novel drug discovery efforts in this challenging field.
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30
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Cellot G, Cherubini E. GABAergic signaling as therapeutic target for autism spectrum disorders. Front Pediatr 2014; 2:70. [PMID: 25072038 PMCID: PMC4085902 DOI: 10.3389/fped.2014.00070] [Citation(s) in RCA: 184] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 06/23/2014] [Indexed: 11/13/2022] Open
Abstract
γ-Aminobutyric acid (GABA), the main inhibitory neurotransmitter in the adult brain, early in postnatal life exerts a depolarizing and excitatory action. This depends on accumulation of chloride inside the cell via the cation-chloride importer NKCC1, being the expression of the chloride exporter KCC2 very low at birth. The developmentally regulated expression of KCC2 results in extrusion of chloride with age and a shift of GABA from the depolarizing to the hyperpolarizing direction. The depolarizing action of GABA leads to intracellular calcium rise through voltage-dependent calcium channels and/or N-methyl-d-aspartate receptors. GABA-mediated calcium signals regulate a variety of developmental processes from cell proliferation migration, differentiation, synapse maturation, and neuronal wiring. Therefore, it is not surprising that some forms of neuro-developmental disorders such as autism spectrum disorders (ASDs) are associated with alterations of GABAergic signaling and impairment of the excitatory/inhibitory balance in selective neuronal circuits. In this review, we will discuss how changes of GABAA-mediated neurotransmission affect several forms of ASDs including the Fragile X, the Angelman, and Rett syndromes. Then, we will describe various animal models of ASDs with GABAergic dysfunctions, highlighting their behavioral deficits and the possibility to rescue them by targeting selective components of the GABAergic synapse. In particular, we will discuss how in some cases, reverting the polarity of GABA responses from the depolarizing to the hyperpolarizing direction with the diuretic bumetanide, a selective blocker of NKCC1, may have beneficial effects on ASDs, thus opening new therapeutic perspectives for the treatment of these devastating disorders.
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Affiliation(s)
- Giada Cellot
- Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati , Trieste , Italy
| | - Enrico Cherubini
- Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati , Trieste , Italy ; European Brain Research Institute , Rome , Italy
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31
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Herbert MR, Sage C. Autism and EMF? Plausibility of a pathophysiological link - Part I. ACTA ACUST UNITED AC 2013; 20:191-209. [PMID: 24095003 DOI: 10.1016/j.pathophys.2013.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Revised: 05/06/2013] [Accepted: 07/15/2013] [Indexed: 01/02/2023]
Abstract
Although autism spectrum conditions (ASCs) are defined behaviorally, they also involve multileveled disturbances of underlying biology that find striking parallels in the physiological impacts of electromagnetic frequency and radiofrequency exposures (EMF/RFR). Part I of this paper will review the critical contributions pathophysiology may make to the etiology, pathogenesis and ongoing generation of core features of ASCs. We will review pathophysiological damage to core cellular processes that are associated both with ASCs and with biological effects of EMF/RFR exposures that contribute to chronically disrupted homeostasis. Many studies of people with ASCs have identified oxidative stress and evidence of free radical damage, cellular stress proteins, and deficiencies of antioxidants such as glutathione. Elevated intracellular calcium in ASCs may be due to genetics or may be downstream of inflammation or environmental exposures. Cell membrane lipids may be peroxidized, mitochondria may be dysfunctional, and various kinds of immune system disturbances are common. Brain oxidative stress and inflammation as well as measures consistent with blood-brain barrier and brain perfusion compromise have been documented. Part II of this paper will review how behaviors in ASCs may emerge from alterations of electrophysiological oscillatory synchronization, how EMF/RFR could contribute to these by de-tuning the organism, and policy implications of these vulnerabilities. Changes in brain and autonomic nervous system electrophysiological function and sensory processing predominate, seizures are common, and sleep disruption is close to universal. All of these phenomena also occur with EMF/RFR exposure that can add to system overload ('allostatic load') in ASCs by increasing risk, and worsening challenging biological problems and symptoms; conversely, reducing exposure might ameliorate symptoms of ASCs by reducing obstruction of physiological repair. Various vital but vulnerable mechanisms such as calcium channels may be disrupted by environmental agents, various genes associated with autism or the interaction of both. With dramatic increases in reported ASCs that are coincident in time with the deployment of wireless technologies, we need aggressive investigation of potential ASC - EMF/RFR links. The evidence is sufficient to warrant new public exposure standards benchmarked to low-intensity (non-thermal) exposure levels now known to be biologically disruptive, and strong, interim precautionary practices are advocated.
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Affiliation(s)
- Martha R Herbert
- TRANSCEND Research Program Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA.
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32
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Whiteley P, Shattock P, Knivsberg AM, Seim A, Reichelt KL, Todd L, Carr K, Hooper M. Gluten- and casein-free dietary intervention for autism spectrum conditions. Front Hum Neurosci 2013; 6:344. [PMID: 23316152 PMCID: PMC3540005 DOI: 10.3389/fnhum.2012.00344] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 12/14/2012] [Indexed: 01/31/2023] Open
Abstract
Dietary intervention as a tool for maintaining and improving physical health and wellbeing is a widely researched and discussed topic. Speculation that diet may similarly affect mental health and wellbeing particularly in cases of psychiatric and behavioral symptomatology opens up various avenues for potentially improving quality of life. We examine evidence suggestive that a gluten-free (GF), casein-free (CF), or gluten- and casein-free diet (GFCF) can ameliorate core and peripheral symptoms and improve developmental outcome in some cases of autism spectrum conditions. Although not wholly affirmative, the majority of published studies indicate statistically significant positive changes to symptom presentation following dietary intervention. In particular, changes to areas of communication, attention, and hyperactivity are detailed, despite the presence of various methodological shortcomings. Specific characteristics of best- and non-responders to intervention have not been fully elucidated; neither has the precise mode of action for any universal effect outside of known individual cases of food-related co-morbidity. With the publication of controlled medium- and long-term group studies of a gluten- and casein-free diet alongside more consolidated biological findings potentially linked to intervention, the appearance of a possible diet-related autism phenotype seems to be emerging supportive of a positive dietary effect in some cases. Further debate on whether such dietary intervention should form part of best practice guidelines for autism spectrum conditions (ASCs) and onward representative of an autism dietary-sensitive enteropathy is warranted.
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Affiliation(s)
- Paul Whiteley
- ESPA Research, The Robert Luff Laboratory, Unit 133i Business and Innovation CentreSunderland, UK
| | - Paul Shattock
- ESPA Research, The Robert Luff Laboratory, Unit 133i Business and Innovation CentreSunderland, UK
| | - Ann-Mari Knivsberg
- National Centre for Reading Education and Research, University of StavangerStavanger, Norway
| | | | - Karl L. Reichelt
- Department of Pediatric Research, Rikshospitalet Medical Centre, University of OsloOslo, Norway
| | - Lynda Todd
- ESPA Research, The Robert Luff Laboratory, Unit 133i Business and Innovation CentreSunderland, UK
| | - Kevin Carr
- ESPA Research, The Robert Luff Laboratory, Unit 133i Business and Innovation CentreSunderland, UK
| | - Malcolm Hooper
- ESPA Research, The Robert Luff Laboratory, Unit 133i Business and Innovation CentreSunderland, UK
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33
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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.
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Affiliation(s)
- Gene J. Blatt
- Department of Anatomy & Neurobiology, School of Medicine, Boston University, 72 East Concord Street L 1004, Boston, MA 02118, USA
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