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Baizer JS. Functional and Neuropathological Evidence for a Role of the Brainstem in Autism. Front Integr Neurosci 2021; 15:748977. [PMID: 34744648 PMCID: PMC8565487 DOI: 10.3389/fnint.2021.748977] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/21/2021] [Indexed: 12/27/2022] Open
Abstract
The brainstem includes many nuclei and fiber tracts that mediate a wide range of functions. Data from two parallel approaches to the study of autistic spectrum disorder (ASD) implicate many brainstem structures. The first approach is to identify the functions affected in ASD and then trace the neural systems mediating those functions. While not included as core symptoms, three areas of function are frequently impaired in ASD: (1) Motor control both of the limbs and body and the control of eye movements; (2) Sensory information processing in vestibular and auditory systems; (3) Control of affect. There are critical brainstem nuclei mediating each of those functions. There are many nuclei critical for eye movement control including the superior colliculus. Vestibular information is first processed in the four nuclei of the vestibular nuclear complex. Auditory information is relayed to the dorsal and ventral cochlear nuclei and subsequently processed in multiple other brainstem nuclei. Critical structures in affect regulation are the brainstem sources of serotonin and norepinephrine, the raphe nuclei and the locus ceruleus. The second approach is the analysis of abnormalities from direct study of ASD brains. The structure most commonly identified as abnormal in neuropathological studies is the cerebellum. It is classically a major component of the motor system, critical for coordination. It has also been implicated in cognitive and language functions, among the core symptoms of ASD. This structure works very closely with the cerebral cortex; the cortex and the cerebellum show parallel enlargement over evolution. The cerebellum receives input from cortex via relays in the pontine nuclei. In addition, climbing fiber input to cerebellum comes from the inferior olive of the medulla. Mossy fiber input comes from the arcuate nucleus of the medulla as well as the pontine nuclei. The cerebellum projects to several brainstem nuclei including the vestibular nuclear complex and the red nucleus. There are thus multiple brainstem nuclei distributed at all levels of the brainstem, medulla, pons, and midbrain, that participate in functions affected in ASD. There is direct evidence that the cerebellum may be abnormal in ASD. The evidence strongly indicates that analysis of these structures could add to our understanding of the neural basis of ASD.
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Affiliation(s)
- Joan S. Baizer
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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Thorkelson G, Laughlin SF, Turner KS, Ober N, Handen BL. Selective Serotonin Reuptake Inhibitor Monotherapy for Anxiety Disorders in Children and Adolescents with Autism Spectrum Disorder: A Chart Review. J Child Adolesc Psychopharmacol 2019; 29:705-711. [PMID: 31295004 DOI: 10.1089/cap.2019.0001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Objective: Anxiety disorders are one of the most commonly co-occurring psychiatric diagnoses in youth with autism spectrum disorder (ASD), with a frequency ranging from 22% to 84%. Methods: We conducted a chart review of 29 children and adolescents with ASD who had been treated with selective serotonin reuptake inhibitor (SSRI) monotherapy for an anxiety disorder for at least 2 months. Subsequent chart reviews were conducted for the first follow-up visit within 2-6 months (M = 4.2 months) and the visit closest to 9 months posttreatment (ranging from 7 to 12 months; M = 10.5 months). The presence of adverse events (AEs) was examined, and a consensus Clinical Global Impressions Improvement (CGI-I) score was determined. Results: Fifty-five percent of patients were given a CGI-I of "improved" or "very much improved" at the 9-month follow-up. Four patients discontinued treatment owing to AEs. Other reported AEs not leading to discontinuation included vivid dreaming, increased emotional lability, and irritability. Responders included a number of patients who had failed previous SSRI trials. Conclusions: This study suggests that SSRI treatment should be considered for individuals with ASD and anxiety disorders, even if prior SSRI trials have been unsuccessful.
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Affiliation(s)
- Gregory Thorkelson
- Department of Psychiatry, Western Psychiatric Hospital, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Sarah F Laughlin
- Department of Physical Medicine and Rehabilitation, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kylan S Turner
- Department of Behavior Analysis, Simmons University, Boston, Massachusetts
| | - Nicole Ober
- Department of Psychiatry, Western Psychiatric Hospital, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Benjamin L Handen
- Department of Psychiatry, Western Psychiatric Hospital, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Witt NA, Lee B, Ghent K, Zhang WQ, Pehrson AL, Sánchez C, Gould GG. Vortioxetine Reduces Marble Burying but Only Transiently Enhances Social Interaction Preference in Adult Male BTBR T +Itpr3 tf/J Mice. ACS Chem Neurosci 2019; 10:4319-4327. [PMID: 31468969 DOI: 10.1021/acschemneuro.9b00386] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Vortioxetine is a multimodal antidepressant with agonist activity at serotonin (5-HT)1A and 5-HT1B receptors that blocks the 5-HT transporter (SERT). Previously in male BTBR T+Itpr3tf/J (BTBR) mice, the 5-HT1A partial agonist buspirone and SERT blocker fluoxetine enhanced social interaction but did not reduce marble burying. We hypothesized that vortioxetine through its actions at SERT and 5-HT1A could improve BTBR sociability and via 5-HT1B could reduce burying better than sertraline, a selective SERT blocker. Vortioxetine (5-10 mg/kg) or sertraline (2 mg/kg) was administered 30 min presociability and 75 min prior to marble burying tests. Vortioxetine (10 mg/kg) occupancy (%) was 84 ± 1 for SERT, 31 ± 12 for 5-HT1A, and 80 ± 5 for 5-HT1B in brain at 110 min postinjection, and serum oxytocin was 24% lower (p < 0.01) in vortioxetine-treated mice. Vortioxetine reduced novel object investigation, whereas sertraline enhanced overall sociability. However, the vortioxetine-induced increase in social sniffing was transient, as it was lost with 60-120 min presociability test delays in subsequent experiments. Vortioxetine and sertraline both reduced BTBR marble burying. Based on vortioxetine occupancy, actions at SERT and/or 5-HT1B are more likely to underlie its behavioral effects than 5-HT1A. Overall, vortioxetine has great potential for suppressing restrictive-repetitive behaviors, but it appears less promising as a sociability enhancer.
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Affiliation(s)
- Nasriya A. Witt
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States
- University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Benita Lee
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States
- University of Texas, Austin, Texas 78705, United States
| | - Kaylee Ghent
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States
- Trinity University, San Antonio, Texas 78212, United States
| | - Wynne Q. Zhang
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States
- Baylor College of Medicine, Houston, Texas 77030, United States
| | - Alan L. Pehrson
- Department of Psychology, Monclair State University, Montclair, New Jersey 07043, United States
| | - Connie Sánchez
- Institute of Clinical Medicine, Translational Neuropsychiatry, University of Aarhus, Risskov, Denmark 8240
| | - Georgianna G. Gould
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States
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Zhang WQ, Smolik CM, Barba-Escobedo PA, Gamez M, Sanchez JJ, Javors MA, Daws LC, Gould GG. Acute dietary tryptophan manipulation differentially alters social behavior, brain serotonin and plasma corticosterone in three inbred mouse strains. Neuropharmacology 2015; 90:1-8. [PMID: 25445490 PMCID: PMC4276517 DOI: 10.1016/j.neuropharm.2014.10.024] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 10/21/2014] [Accepted: 10/26/2014] [Indexed: 12/22/2022]
Abstract
Clinical evidence indicates brain serotonin (5-HT) stores and neurotransmission may be inadequate in subpopulations of individuals with autism, and this may contribute to characteristically impaired social behaviors. Findings that depletion of the 5-HT precursor tryptophan (TRP) worsens autism symptoms support this hypothesis. Yet dietetic studies show and parents report that many children with autism consume less TRP than peers. To measure the impact of dietary TRP content on social behavior, we administered either diets devoid of TRP, with standard TRP (0.2 g%), or with 1% added TRP (1.2 g%) overnight to three mouse strains. Of these, BTBRT(+)Itpr3(tf)/J and 129S1/SvImJ consistently exhibit low preference for social interaction relative to C57BL/6. We found that TRP depletion reduced C57BL/6 and 129S social interaction preference, while TRP enhancement improved BTBR sociability (p < 0.05; N = 8-10). Subsequent marble burying did not differ among diets or strains. After behavior tests, brain TRP levels and plasma corticosterone were higher in TRP enhanced C57BL/6 and BTBR, while 5-HT levels were reduced in all strains by TRP depletion (p < 0.05; N = 4-10). Relative hyperactivity of BTBR and hypoactivity of 129S, evident in self-grooming and chamber entries during sociability tests, were uninfluenced by dietary TRP. Our findings demonstrate mouse sociability and brain 5-HT turnover are reduced by acute TRP depletion, and can be enhanced by TRP supplementation. This outcome warrants further basic and clinical studies employing biomarker combinations such as TRP metabolism and 5-HT regulated hormones to characterize conditions wherein TRP supplementation may best ameliorate sociability deficits.
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Affiliation(s)
- Wynne Q Zhang
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Rice University, Houston, TX 77005, USA
| | - Corey M Smolik
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Priscilla A Barba-Escobedo
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Texas A&M University at San Antonio, TX 78224, USA
| | - Monica Gamez
- Texas A&M University at San Antonio, TX 78224, USA
| | - Jesus J Sanchez
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Martin A Javors
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Lynette C Daws
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Georgianna G Gould
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
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Vannucchi G, Masi G, Toni C, Dell'Osso L, Erfurth A, Perugi G. Bipolar disorder in adults with Asperger׳s Syndrome: a systematic review. J Affect Disord 2014; 168:151-60. [PMID: 25046741 DOI: 10.1016/j.jad.2014.06.042] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/18/2014] [Accepted: 06/24/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Asperger׳s Syndrome (AS) is a neurodevelopmental disorder included in the Autism Spectrum (ASD). The current literature shows growing evidence of a high rate of comorbidity between AS and other psychiatric disorders, particularly Bipolar Disorder (BD). We reviewed available epidemiological and clinical data on BD-AS comorbidity and its diagnostic and therapeutic implications METHODS A systematic review of the literature was conducted through PubMed, Scopus and Psych-Info using combinations of the following search terms: Asperger׳s Syndrome, Bipolar Disorder, depression, mood disorder, psychiatric comorbidity, treatment, mood stabilizers, anticonvulsants, antipsychotics, and antidepressants. RESULTS BD prevalence in adults with AS ranges from 6% to 21.4% of the cases. Relatives of patients with AS showed a doubled risk of being affected by BD and a BD prevalence near to 10%. When comorbid with AS, BD assumes peculiar features which might shape its under-recognition or misdiagnosis (especially schizophrenia when psychotic symptoms are prominent). Although controlled data on pharmacological treatments in BD-AS comorbidity are substantially lacking, information is derived by open observations, case series and chart reviews. Mood stabilizers should be considered the first choice, and antipsychotics, especially second generation drugs (SGA) with 5-HT2a antagonism, have been shown useful in controlling psychotic and behavioral symptoms and improving social withdrawal. Some evidence of efficacy for the treatment of anxiety, obsessive-compulsive symptoms and depression is reported for SSRI antidepressants. The use of these drugs should be carefully monitored, because activation with hypomanic or manic switches is reported up to 54% of the treated subjects. CONCLUSION BD in AS patients is frequent, usually it onsets during adolescence and is often characterized by atypical presentation, making its correct identification particularly difficult. A correct diagnosis of BD in AS individuals has relevant implications on the choice of adequate psychopharmacological, psycho-social and rehabilitative treatments.
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Affiliation(s)
- Giulia Vannucchi
- Department of Clinical and Experimental Medicine, Psychiatry Unit, University of Pisa, Italy
| | - Gabriele Masi
- IRCCS Stella Maris, Scientific Institute of Child Neurology and Psychiatry, Via dei Giacinti 2, 56018 Calambrone (Pisa), Italy
| | - Cristina Toni
- Institute of Behavioural Sciences "G. De Lisio", Via di Pratale 3, 56100 Pisa, Italy
| | - Liliana Dell'Osso
- Department of Clinical and Experimental Medicine, Psychiatry Unit, University of Pisa, Italy
| | - Andreas Erfurth
- Otto Wagner Psychiatric Hospital of Vienna, Head of Department VI, Vienna, Austria
| | - Giulio Perugi
- Department of Clinical and Experimental Medicine, Psychiatry Unit, University of Pisa, Institute of Behavioral Sciences "G. De Lisio", Via Roma, 67, 56100 Pisa, Italy.
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Daws LC, Gould GG. Ontogeny and regulation of the serotonin transporter: providing insights into human disorders. Pharmacol Ther 2011; 131:61-79. [PMID: 21447358 DOI: 10.1016/j.pharmthera.2011.03.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 03/11/2011] [Indexed: 12/17/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) was one of the first neurotransmitters for which a role in development was identified. Pharmacological and gene knockout studies have revealed a critical role for 5-HT in numerous processes, including cell division, neuronal migration, differentiation and synaptogenesis. An excess in brain 5-HT appears to be mechanistically linked to abnormal brain development, which in turn is associated with neurological disorders. Ambient levels of 5-HT are controlled by a vast orchestra of proteins, including a multiplicity of pre- and post-synaptic 5-HT receptors, heteroreceptors, enzymes and transporters. The 5-HT transporter (SERT, 5-HTT) is arguably the most powerful regulator of ambient extracellular 5-HT. SERT is the high-affinity uptake mechanism for 5-HT and exerts tight control over the strength and duration of serotonergic neurotransmission. Perturbation of its expression level or function has been implicated in many diseases, prominent among them are psychiatric disorders. This review synthesizes existing information on the ontogeny of SERT during embryonic and early postnatal development though adolescence, along with factors that influence its expression and function during these critical developmental windows. We integrate this knowledge to emphasize how inappropriate SERT expression or its dysregulation may be linked to the pathophysiology of psychiatric, cardiovascular and gastrointestinal diseases.
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Affiliation(s)
- Lynette C Daws
- Department of Physiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MC 7756, San Antonio, TX 78229-3900, USA.
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Gould GG, Hensler JG, Burke TF, Benno RH, Onaivi ES, Daws LC. Density and function of central serotonin (5-HT) transporters, 5-HT1A and 5-HT2A receptors, and effects of their targeting on BTBR T+tf/J mouse social behavior. J Neurochem 2011; 116:291-303. [PMID: 21070242 PMCID: PMC3012263 DOI: 10.1111/j.1471-4159.2010.07104.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BTBR mice are potentially useful tools for autism research because their behavior parallels core social interaction impairments and restricted-repetitive behaviors. Altered regulation of central serotonin (5-HT) neurotransmission may underlie such behavioral deficits. To test this, we compared 5-HT transporter (SERT), 5-HT(1A) and 5-HT(2A) receptor densities among BTBR and C57 strains. Autoradiographic [(3) H] cyanoimipramine (1 nM) binding to SERT was 20-30% lower throughout the adult BTBR brain as compared to C57BL/10J mice. In hippocampal membrane homogenates, [(3) H] citalopram maximal binding (B(max) ) to SERT was 95 ± 13 fmol/mg protein in BTBR and 171 ± 20 fmol/mg protein in C57BL/6J mice, and the BTBR dissociation constant (K(D) ) was 2.0 ± 0.3 nM versus 1.1 ± 0.2 in C57BL/6J mice. Hippocampal 5-HT(1A) and 5-HT(2A) receptor binding was similar among strains. However, 8-OH-DPAT-stimulated [(35) S] GTPγS binding in the BTBR hippocampal CA(1) region was 28% higher, indicating elevated 5-HT(1A) capacity to activate G-proteins. In BTBR mice, the SERT blocker, fluoxetine (10 mg/kg) and the 5-HT(1A) receptor partial-agonist, buspirone (2 mg/kg) enhanced social interactions. The D(2) /5-HT(2) receptor antagonist, risperidone (0.1 mg/kg) reduced marble burying, but failed to improve sociability. Overall, altered SERT and/or 5-HT(1A) functionality in hippocampus could contribute to the relatively low sociability of BTBR mice.
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MESH Headings
- Animals
- Brain/drug effects
- Brain/metabolism
- Brain/physiology
- Buspirone/pharmacology
- Fluoxetine/pharmacology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Protein Binding/physiology
- Protein Transport
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptor, Serotonin, 5-HT1A/physiology
- Receptor, Serotonin, 5-HT2A/metabolism
- Receptor, Serotonin, 5-HT2A/physiology
- Serotonin Plasma Membrane Transport Proteins/metabolism
- Serotonin Plasma Membrane Transport Proteins/physiology
- Social Behavior
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Affiliation(s)
- Georgianna G Gould
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA.
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