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Krishnappa Babu PR, Aikat V, Di Martino JM, Chang Z, Perochon S, Espinosa S, Aiello R, L H Carpenter K, Compton S, Davis N, Eichner B, Flowers J, Franz L, Dawson G, Sapiro G. Blink rate and facial orientation reveal distinctive patterns of attentional engagement in autistic toddlers: a digital phenotyping approach. Sci Rep 2023; 13:7158. [PMID: 37137954 PMCID: PMC10156751 DOI: 10.1038/s41598-023-34293-7] [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: 10/27/2022] [Accepted: 04/27/2023] [Indexed: 05/05/2023] Open
Abstract
Differences in social attention are well-documented in autistic individuals, representing one of the earliest signs of autism. Spontaneous blink rate has been used to index attentional engagement, with lower blink rates reflecting increased engagement. We evaluated novel methods using computer vision analysis (CVA) for automatically quantifying patterns of attentional engagement in young autistic children, based on facial orientation and blink rate, which were captured via mobile devices. Participants were 474 children (17-36 months old), 43 of whom were diagnosed with autism. Movies containing social or nonsocial content were presented via an iPad app, and simultaneously, the device's camera recorded the children's behavior while they watched the movies. CVA was used to extract the duration of time the child oriented towards the screen and their blink rate as indices of attentional engagement. Overall, autistic children spent less time facing the screen and had a higher mean blink rate compared to neurotypical children. Neurotypical children faced the screen more often and blinked at a lower rate during the social movies compared to the nonsocial movies. In contrast, autistic children faced the screen less often during social movies than during nonsocial movies and showed no differential blink rate to social versus nonsocial movies.
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Affiliation(s)
| | - Vikram Aikat
- Department of Computer Science, Duke University, Durham, NC, USA
| | - J Matias Di Martino
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Zhuoqing Chang
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Sam Perochon
- Ecole Normale Supérieure Paris-Saclay, Gif-Sur-Yvette, France
| | - Steven Espinosa
- Office of Information Technology, Duke University, Durham, NC, USA
| | - Rachel Aiello
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
- Duke Center for Autism and Brain Development, Duke University, Durham, NC, USA
| | - Kimberly L H Carpenter
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
- Duke Center for Autism and Brain Development, Duke University, Durham, NC, USA
| | - Scott Compton
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
- Duke Center for Autism and Brain Development, Duke University, Durham, NC, USA
| | - Naomi Davis
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
- Duke Center for Autism and Brain Development, Duke University, Durham, NC, USA
| | - Brian Eichner
- Department of Pediatrics, Duke University, Durham, NC, USA
| | - Jacqueline Flowers
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
- Duke Center for Autism and Brain Development, Duke University, Durham, NC, USA
| | - Lauren Franz
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA
- Duke Center for Autism and Brain Development, Duke University, Durham, NC, USA
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Geraldine Dawson
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA.
- Duke Center for Autism and Brain Development, Duke University, Durham, NC, USA.
| | - Guillermo Sapiro
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
- Departments of Biomedical Engineering, Mathematics, and Computer Science, Duke University, Durham, NC, USA.
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Dichter GS, Rodriguez-Romaguera J. Anhedonia and Hyperhedonia in Autism and Related Neurodevelopmental Disorders. Curr Top Behav Neurosci 2022; 58:237-254. [PMID: 35397066 DOI: 10.1007/7854_2022_312] [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: 06/14/2023]
Abstract
Although autism spectrum disorder (ASD) is defined by impaired social communication and restricted and repetitive behaviors and interests, ASD is also characterized by impaired motivational processes. The "social motivation theory of autism" describes how social motivation disruptions in ASD in early childhood may impede the drive to engage in reciprocal social behaviors and ultimately interfere with the development of neural networks critical for social communication (Chevallier et al., Trends Cogn Sci 16:231-239, 2012b). Importantly, clinical studies and preclinical research using model organisms for ASD indicate that motivational impairments in ASD are not constrained to social rewards but are evident in response to a range of nonsocial rewards as well. Additionally, translational studies on certain genetically defined neurodevelopmental disorders associated with ASD indicate that these syndromic forms of ASD are also characterized by motivational deficits and mesolimbic dopamine impairments. In this chapter we summarize clinical and preclinical research relevant to reward processing impairments in ASD and related neurodevelopmental disorders. We also propose a nosology to describe reward processing impairments in these disorders that uses a three-axes model. In this triaxial nosology, the first axis defines the direction of the reward response (i.e., anhedonic, hyperhedonic); the second axis defines the construct of the reward process (e.g., reward liking, reward wanting); and the third axis defines the context of the reward response (e.g., social, nonsocial). A more precise nosology for describing reward processing impairments in ASD and related neurodevelopmental disorders will aid in the translation of preclinical research to clinical investigations which will ultimately help to speed up the development of interventions that target motivational systems for ASD and related neurodevelopmental disorders.
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Affiliation(s)
- Gabriel S Dichter
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Jose Rodriguez-Romaguera
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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Abstract
OBJECTIVES The purpose of this systematic literature review is to describe what is known about fragile X syndrome (FXS) and to identify research gaps. The results can be used to help inform future public health research and provide pediatricians with up-to-date information about the implications of the condition for individuals and their families. METHODS An electronic literature search was conducted, guided by a variety of key words. The search focused on 4 areas of both clinical and public health importance: (1) the full mutation phenotype, (2) developmental trajectories across the life span, (3) available interventions and treatments, and (4) impact on the family. A total of 661 articles were examined and 203 were included in the review. RESULTS The information is presented in the following categories: developmental profile (cognition, language, functional skills, and transition to adulthood), social-emotional profile (cooccurring psychiatric conditions and behavior problems), medical profile (physical features, seizures, sleep, health problems, and physiologic features), treatment and interventions (educational/behavioral, allied health services, and pharmacologic), and impact on the family (family environment and financial impact). Research gaps also are presented. CONCLUSIONS The identification and treatment of FXS remains an important public health and clinical concern. The information presented in this article provides a more robust understanding of FXS and the impact of this complex condition for pediatricians. Despite a wealth of information about the condition, much work remains to fully support affected individuals and their families.
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Affiliation(s)
- Melissa Raspa
- RTI International, Research Triangle Park, North Carolina; and
| | - Anne C Wheeler
- RTI International, Research Triangle Park, North Carolina; and
| | - Catharine Riley
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia
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Bacher LF, Retz S, Lindon C, Bell MA. Intraindividual and Interindividual Differences in Spontaneous Eye Blinking: Relationships to Working Memory Performance and Frontal EEG Asymmetry. INFANCY 2017; 22:150-170. [PMID: 28286427 PMCID: PMC5343288 DOI: 10.1111/infa.12164] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rate and timing of spontaneous eye blinking (SB) may be used to explore mechanisms of cognitive activity in infancy. In particular, SB rate is believed to reflect some dimensions of dopamine function; therefore, we hypothesized that SB rate would relate to working memory performance and to frontal electroencephalogram (EEG) asymmetry. Forty, 10-mo-old infants completed an A-not-B task while SB and EEG were measured throughout. We found that SB rate varied across phases of the task, variability in SB rate was positively related to working memory performance, and frontal EEG asymmetry was related to individual differences in the rate of SB. Results provide indirect, but convergent support for the hypothesis that SB rate reflects dopamine function early in human development. As such, these results have implications for understanding the tonic and phasic effects of dopamine on cognitive activity early in human development.
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Zhang T, Zhang Q, Wang C, Chen A. The developmental relationship between central dopaminergic level and response inhibition from late childhood to young adulthood. Int J Psychophysiol 2017; 116:53-59. [PMID: 28219681 DOI: 10.1016/j.ijpsycho.2017.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 11/16/2022]
Abstract
Dopamine (DA) is known to modulate response inhibition (RI). In contrast to the abundant adult studies, only few developmental studies have focused on this topic. Moreover, the mechanism underlying the modulation of RI by the DA system from childhood to adulthood remains unclear. We aimed to assess whether the relationship between DA and RI during late childhood and young adulthood is similar. Accordingly, DA function was measured using the spontaneous eye blink rate (EBR), whereas RI ability was tested using the Go/Nogo task. Experiment 1 included 149 adults (age range, 18-25years) who completed the EBR test and the Go/Nogo task; the results showed that higher EBR was associated with lower commission error in the Nogo trials. Experiment 2 included 45 children (age range, 10-12years) and 37 adults (age range, 18-19years) who completed the EBR test and Go/Nogo tasks (similar to experiment 1); in both the child and adult groups, higher EBR was related to better RI ability. As EBR is closely related to central DA function, these findings suggest that DA plays a similar role in the processing of RI in late childhood and young adulthood.
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Affiliation(s)
- Ting Zhang
- School of Psychology, Southwest University, Chongqing, China.
| | - Qin Zhang
- School of Political Science and Public Administration, University of Electronic Science and Technology of China, China
| | - Cuicui Wang
- State Key Lab of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Antao Chen
- School of Psychology, Southwest University, Chongqing, China.
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Spontaneous eye blink rate as predictor of dopamine-related cognitive function-A review. Neurosci Biobehav Rev 2016; 71:58-82. [PMID: 27555290 DOI: 10.1016/j.neubiorev.2016.08.020] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/29/2016] [Accepted: 08/16/2016] [Indexed: 12/18/2022]
Abstract
An extensive body of research suggests the spontaneous eye blink rate (EBR) is a non-invasive indirect marker of central dopamine (DA) function, with higher EBR predicting higher DA function. In the present review we provide a comprehensive overview of this literature. We broadly divide the available research in studies that aim to disentangle the dopaminergic underpinnings of EBR, investigate its utility in diagnosis of DA-related disorders and responsivity to drug treatment, and, lastly, investigate EBR as predictor of individual differences in DA-related cognitive performance. We conclude (i) EBR can reflect both DA receptor subtype D1 and D2 activity, although baseline EBR might be most strongly related to the latter, (ii) EBR can predict hypo- and hyperdopaminergic activity as well as normalization of this activity following treatment, and (iii) EBR can reliably predict individual differences in performance on many cognitive tasks, in particular those related to reward-driven behavior and cognitive flexibility. In sum, this review establishes EBR as a useful predictor of DA in a wide variety of contexts.
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Wang H, Pati S, Pozzo-Miller L, Doering LC. Targeted pharmacological treatment of autism spectrum disorders: fragile X and Rett syndromes. Front Cell Neurosci 2015; 9:55. [PMID: 25767435 PMCID: PMC4341567 DOI: 10.3389/fncel.2015.00055] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 02/05/2015] [Indexed: 12/27/2022] Open
Abstract
Autism spectrum disorders (ASDs) are genetically and clinically heterogeneous and lack effective medications to treat their core symptoms. Studies of syndromic ASDs caused by single gene mutations have provided insights into the pathophysiology of autism. Fragile X and Rett syndromes belong to the syndromic ASDs in which preclinical studies have identified rational targets for drug therapies focused on correcting underlying neural dysfunction. These preclinical discoveries are increasingly translating into exciting human clinical trials. Since there are significant molecular and neurobiological overlaps among ASDs, targeted treatments developed for fragile X and Rett syndromes may be helpful for autism of different etiologies. Here, we review the targeted pharmacological treatment of fragile X and Rett syndromes and discuss related issues in both preclinical studies and clinical trials of potential therapies for the diseases.
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Affiliation(s)
- Hansen Wang
- Faculty of Medicine, University of Toronto, 1 King's College Circle Toronto, ON, Canada
| | - Sandipan Pati
- Department of Neurology, Epilepsy Division, The University of Alabama at Birmingham Birmingham, AL, USA
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham Birmingham, AL, USA
| | - Laurie C Doering
- Faculty of Health Sciences, Department of Pathology and Molecular Medicine, McMaster University Hamilton, ON, Canada
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Wrenn CC, Heitzer AM, Roth AK, Nawrocki L, Valdovinos MG. Effects of clonidine and methylphenidate on motor activity in Fmr1 knockout mice. Neurosci Lett 2014; 585:109-13. [PMID: 25433180 DOI: 10.1016/j.neulet.2014.11.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 11/04/2014] [Accepted: 11/24/2014] [Indexed: 01/27/2023]
Abstract
Fragile X syndrome (FXS), a disorder caused by a mutation in the FMR1 gene, is often associated with Attention Deficit Hyperactivity Disorder (ADHD). Common treatments for the hyperactivity often seen in ADHD involve the use of stimulants and α2-adrenergic agonists. The Fmr1 knockout (KO) mouse has been found to be a valid model for FXS both biologically and behaviorally. Of particular interest to our research, the Fmr1 KO mouse has been demonstrated to show increased locomotion in comparison to wild type (WT) littermates. In the present study, we assessed the effects of clonidine (0.05 mg/kg) and methylphenidate (5 mg/kg) on motor activity in Fmr1 KO mice and their WT littermates in the open field test. Results showed that methylphenidate increased motor activity in both genotypes. Clonidine decreased motor activity in both genotypes, but the effect was delayed in the Fmr1 KO mice.
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Affiliation(s)
- Craige C Wrenn
- College of Pharmacy & Health Sciences, Drake University, 2507 University Avenue, Des Moines, IA 50311, USA
| | - Andrew M Heitzer
- Department of Psychology, Drake University, 2507 University Avenue, Des Moines, IA 50311, USA
| | - Alexandra K Roth
- Department of Psychology, Drake University, 2507 University Avenue, Des Moines, IA 50311, USA
| | - Lauren Nawrocki
- Neuroscience Program, Drake University, 2507 University Avenue, Des Moines, IA 50311, USA
| | - Maria G Valdovinos
- Department of Psychology, Drake University, 2507 University Avenue, Des Moines, IA 50311, USA.
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Bacher L. Development and manipulation of spontaneous eye blinking in the first year: Relationships to context and positive affect. Dev Psychobiol 2013; 56:783-96. [DOI: 10.1002/dev.21148] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 06/07/2013] [Indexed: 11/12/2022]
Affiliation(s)
- L.F. Bacher
- Department of Psychology; SUNY Oswego; 7060 State Rt 104 West Oswego NY 13126
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10
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Wolff JJ, Hazlett HC, Lightbody AA, Reiss AL, Piven J. Repetitive and self-injurious behaviors: associations with caudate volume in autism and fragile X syndrome. J Neurodev Disord 2013; 5:12. [PMID: 23639144 PMCID: PMC3651404 DOI: 10.1186/1866-1955-5-12] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/17/2013] [Indexed: 11/13/2022] Open
Abstract
Background Following from previous work suggesting that neurobehavioral features distinguish fragile X and idiopathic variants of autism, we investigated the relationships between four forms of repetitive behavior (stereotypy, self-injury, compulsivity, ritual behavior) and caudate nuclei volume in two groups: boys with fragile X syndrome, a subset of whom met criteria for autism, and a comparison group of boys with idiopathic autism. Methods Bilateral caudate nuclei volumes were measured in boys aged 3 to 6 years with fragile X syndrome (n = 41), the subset of boys with fragile X syndrome and autism (n = 16), and boys with idiopathic autism (n = 30). Repetitive behaviors were measured using the Repetitive Behavior Scales-Revised. Results For boys with idiopathic autism, left caudate volume was modestly associated with self-injury, while both compulsive and ritual behaviors showed significant positive correlations with bilateral caudate nuclei volumes, replicating previous results. For boys with fragile X syndrome, there was no such association between caudate volume and compulsive behaviors. However, we did identify significant positive correlations between self-injury total scores and number of self-injury topographies with bilateral caudate nuclei volumes. Conclusions These findings suggest a specific role for the caudate nucleus in the early pathogenesis of self-injurious behavior associated with both idiopathic autism and fragile X syndrome. Results further indicate that the caudate may be differentially associated with compulsive behavior, highlighting the utility of isolating discrete brain-behavior associations within and between subtypes of autism spectrum disorder.
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Affiliation(s)
- Jason J Wolff
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill School of Medicine, CB# 3367, Chapel Hill, NC, 27599, USA.
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Paul K, Venkitaramani DV, Cox CL. Dampened dopamine-mediated neuromodulation in prefrontal cortex of fragile X mice. J Physiol 2012; 591:1133-43. [PMID: 23148316 DOI: 10.1113/jphysiol.2012.241067] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inheritable mental retardation caused by transcriptional silencing of the Fmr1 gene resulting in the absence of fragile X mental retardation protein (FMRP). The role of this protein in neurons is complex and its absence gives rise to diverse alterations in neuronal function leading to neurological disorders including mental retardation, hyperactivity, cognitive impairment, obsessive-compulsive behaviour, seizure activity and autism. FMRP regulates mRNA translation at dendritic spines where synapses are formed, and thus the lack of FMRP can lead to disruptions in synaptic transmission and plasticity. Many of these neurological deficits in FXS probably involve the prefrontal cortex, and in this study, we have focused on modulatory actions of dopamine in the medial prefrontal cortex. Our data indicate that dopamine produces a long-lasting enhancement of evoked inhibitory postsynaptic currents (IPSCs) mediated by D1-type receptors seen in wild-type mice; however, such enhancement is absent in the Fmr1 knock-out (Fmr1 KO) mice. The facilitation of IPSCs produced by direct cAMP stimulation was unaffected in Fmr1 KO, but D1 receptor levels were reduced in these animals. Our results show significant disruption of dopaminergic modulation of synaptic transmission in the Fmr1 KO mice and this alteration in inhibitory activity may provide insight into potential targets for the rescue of deficits associated with FXS.
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Affiliation(s)
- Kush Paul
- Department of Molecular and Integrative Physiology, University of Illinois, Urbana, IL 61801, USA.
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Dichter GS, Damiano CA, Allen JA. Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: animal models and clinical findings. J Neurodev Disord 2012; 4:19. [PMID: 22958744 PMCID: PMC3464940 DOI: 10.1186/1866-1955-4-19] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/02/2012] [Indexed: 02/07/2023] Open
Abstract
This review summarizes evidence of dysregulated reward circuitry function in a range of neurodevelopmental and psychiatric disorders and genetic syndromes. First, the contribution of identifying a core mechanistic process across disparate disorders to disease classification is discussed, followed by a review of the neurobiology of reward circuitry. We next consider preclinical animal models and clinical evidence of reward-pathway dysfunction in a range of disorders, including psychiatric disorders (i.e., substance-use disorders, affective disorders, eating disorders, and obsessive compulsive disorders), neurodevelopmental disorders (i.e., schizophrenia, attention-deficit/hyperactivity disorder, autism spectrum disorders, Tourette's syndrome, conduct disorder/oppositional defiant disorder), and genetic syndromes (i.e., Fragile X syndrome, Prader-Willi syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome). We also provide brief overviews of effective psychopharmacologic agents that have an effect on the dopamine system in these disorders. This review concludes with methodological considerations for future research designed to more clearly probe reward-circuitry dysfunction, with the ultimate goal of improved intervention strategies.
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Affiliation(s)
- Gabriel S Dichter
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Psychiatry, University of North Carolina School of Medicine, CB# 7255, 101 Manning Drive, Chapel Hill, NC, 275997255, USA
| | - Cara A Damiano
- Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - John A Allen
- Neuroscience Research Unit Pfizer Global Research and Development, Groton, CT 06340, USA
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Abstract
Fragile X syndrome (FXS) is associated with a complex but relatively consistent psychiatric phenotype. Recent research has suggested neural substrates for the behavioral abnormalities typically seen in FXS, and enhanced treatment strategies for managing disabling psychiatric comorbidity. While disease-specific, and possibly disease-modifying, therapeutics are being developed for FXS, currently available psychiatric medications can provide significant symptomatic relief of the hyperactivity, anxiety disorders, and affective disturbances often seen in the course of FXS. However, patients with fragile X may be especially susceptible to the psychiatric side effects of these medications, requiring particular care in prescribing. Recent findings concerning disease mechanisms and treatment strategies are reviewed from the perspective of a clinical psychiatrist, in an effort to enhance conventional pharmacotherapy of FXS.
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Tranfaglia MR. The psychiatric presentation of fragile x: evolution of the diagnosis and treatment of the psychiatric comorbidities of fragile X syndrome. Dev Neurosci 2011; 33:337-48. [PMID: 21893938 DOI: 10.1159/000329421] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 03/10/2011] [Indexed: 11/19/2022] Open
Abstract
Fragile X syndrome (FXS) is the leading inherited cause of mental retardation and autism spectrum disorders worldwide. It presents with a distinct behavioral phenotype which overlaps significantly with that of autism. Unlike autism and most common psychiatric disorders, the neurobiology of fragile X is relatively well understood. Lack of the fragile X mental retardation protein causes dysregulation of synaptically driven protein synthesis, which in turn causes global disruption of synaptic plasticity. Thus, FXS can be considered a disorder of synaptic plasticity, and a developmental disorder in the purest sense: mutation of the FMR1 (fragile X mental retardation 1) gene results in abnormal synaptic development in response to experience. Accumulation of this abnormal synaptic development, over time, leads to a characteristic and surprisingly consistent behavioral phenotype of attention deficit, hyperactivity, impulsivity, multiple anxiety symptoms, repetitive/perseverative/stereotypic behaviors, unstable affect, aggression, and self-injurious behavior. Many features of the behavioral and psychiatric phenotype of FXS follow a developmental course, waxing and waning over the life span. In most cases, symptoms present as a mixed clinical picture, not fitting established diagnostic categories. There have been many clinical trials in fragile X subjects, but no placebo-controlled trials of adequate size or methodology utilizing the most commonly prescribed psychiatric medications. However, large and well-designed trials of investigational agents which target the underlying pathology of FXS have recently been completed or are under way. While the literature offers little guidance to the clinician treating patients with FXS today, potentially disease-modifying treatments may be available in the near future.
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Abstract
Spontaneous blinking is essential for maintaining a healthy ocular surface and clarity of vision. The spontaneous blink rate (SBR) is believed to reflect a complex interaction between peripheral influences mediated by the eye surface and the central dopaminergic activity. The SBR is thus extremely variable and dependent on a variety of psychological and medical conditions. Many different methods have been employed to measure the SBR and the upper eyelid kinematics during a blink movement. Each has its own merits and drawbacks, and the choice of a specific method should be tailored to the specific needs of the investigation. Although the sequence of muscle events that leads to a blink has been fully described, knowledge about the neural control of spontaneous blinking activity is not complete. The tear film is dynamically modified between blinks, and abnormalities of the blink rate have an obvious influence on the ocular surface.
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Affiliation(s)
- Antonio A V Cruz
- Department of Ophthalmology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
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Heilman KJ, Harden ER, Zageris DM, Berry-Kravis E, Porges SW. Autonomic regulation in fragile X syndrome. Dev Psychobiol 2011; 53:785-95. [PMID: 21547900 DOI: 10.1002/dev.20551] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 04/02/2011] [Indexed: 01/28/2023]
Abstract
Autonomic reactivity was studied in individuals with fragile X syndrome (FXS), a genetic disorder partially characterized by abnormal social behavior. Relative to age-matched controls, the FXS group had faster baseline heart rate and lower amplitude respiratory sinus arrhythmia (RSA). In contrast to the typically developing controls, there was a decrease in RSA with age within the FXS group. Moreover, within the FXS group heart rate did not slow with age. The FXS group also responded with an atypical increase in RSA to the social challenge, while the control group reduced RSA. In a subset of the FXS group, the autonomic profile did not change following 2 months and 1 year of lithium treatment. The observed indices of atypical autonomic regulation, consistent with the Polyvagal Theory, may contribute to the deficits in social behavior and social communication observed in FXS.
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Affiliation(s)
- Keri J Heilman
- Department of Psychiatry, Brain-Body Center (MC 912), University of Illinois at Chicago, USA
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Bacher LF, Allen KJ. Sensitivity of the rate of spontaneous eye blinking to type of stimuli in young infants. Dev Psychobiol 2009; 51:186-97. [PMID: 19062172 DOI: 10.1002/dev.20357] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although progress has been made toward understanding the mechanisms of spontaneous eye blinking (SB), few reports focus on the ontogeny of SB. The purpose of the present work was to investigate SB in infants by attempting to manipulate SB and examine potential correlates of SB. Fifty-two infants were observed in a quiet baseline condition then presented with either moving stimuli or a social stimulus. SB, eye movement, body movement and various background variables were measured. Results demonstrate that SB can be manipulated and that SB rate is differentially sensitive to the type of stimulus presented. Eye and body movements did not systematically relate to the rate of SB. Implications for mechanisms of SB regulation are discussed.
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Affiliation(s)
- Leigh F Bacher
- Department of Psychology, State University of New York at Oswego, 455 Mahar Hall, Oswego, NY 13126, USA.
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Govaerts LCP, Smit AE, Saris JJ, VanderWerf F, Willemsen R, Bakker CE, De Zeeuw CI, Oostra BA. Exceptional good cognitive and phenotypic profile in a male carrying a mosaic mutation in the FMR1 gene. Clin Genet 2007; 72:138-44. [PMID: 17661818 DOI: 10.1111/j.1399-0004.2007.00829.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fragile X (FRAX) syndrome is a commonly inherited form of mental retardation resulting from the lack of expression of the fragile X mental retardation protein (FMRP). It is caused by a stretch of CGG repeats within the fragile X gene, which can be unstable in length as it is transmitted from generation to generation. Once the repeat exceeds a threshold length, the FMR1 gene is methylated and no protein is produced resulting in the fragile X phenotype. The consequences of FMRP absence in the mechanisms underlying mental retardation are unknown. We have identified a male patient in a classical FRAX family without the characteristic FRAX phenotype. His intelligence quotient (IQ) is borderline normal despite the presence of a mosaic pattern of a pre-mutation (25%), full mutation (60%) and a deletion (15%) in the FMR1 gene. The cognitive performance was determined at the age of 28 by the Raven test and his IQ was 81. However, FMRP expression studies in both hair roots and lymphocytes, determined at the same time as the IQ test, were within the affected male range. The percentage of conditioned responses after delay eyeblink conditioning was much higher than the average percentage measured in FRAX studies. Moreover, this patient showed no correlation between FMRP expression and phenotype and no correlation between DNA diagnostics and phenotype.
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Affiliation(s)
- L C P Govaerts
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
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Scerif G, Cornish K, Wilding J, Driver J, Karmiloff-Smith A. Delineation of early attentional control difficulties in fragile X syndrome: focus on neurocomputational changes. Neuropsychologia 2007; 45:1889-98. [PMID: 17254617 PMCID: PMC2613507 DOI: 10.1016/j.neuropsychologia.2006.12.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 11/27/2006] [Accepted: 12/03/2006] [Indexed: 11/23/2022]
Abstract
Fragile X syndrome (FXS) is due to the silencing of a single X-linked gene and it is associated with striking attentional difficulties. As FXS is well characterised at the cellular level, the condition provides a unique opportunity to investigate how a genetic dysfunction can impact on the development of neurocomputational properties relevant to attention. Thirteen young boys with FXS and 13 mental-age-matched typically developing controls performed a touch-screen-based search task that manipulated the similarity between targets and distractors and their heterogeneity in size. Search speed, path and errors were recorded as multiple measures of performance. Children did not differ in overall search speed or path when searching amongst distractors, but striking error patterns distinguished children with FXS from controls. Firstly, although clear markers of previously found targets remained on screen, children with FXS perseverated on touching previous hits more than typically developing controls, consistent with the well-documented inhibitory deficits in adults with the disorder. Secondly, they could accurately discriminate single target-distractor pairs, but, when searching a complex display, they touched distractors more often than control children when distractors were similar to targets and especially so when these were infrequent, highlighting difficulties in judging relative size and allocate attentional weight independently of stimulus frequency. Thirdly, their performance was also characterised by inaccuracies in pointing, suggesting additional motor control deficits. Taken together, the findings suggest that fragile X syndrome affects the early development of multiple processes contributing to efficient attentional selection, as would be predicted from an understanding of the neurocomputational changes associated with the disorder.
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Affiliation(s)
- Gaia Scerif
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.
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