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Whelan TP, Daly E, Puts NA, Malievskaia E, Murphy DGM, McAlonan GM. Editorial Perspective: Bridging the translational neuroscience gap in autism - development of the 'shiftability' paradigm. J Child Psychol Psychiatry 2024; 65:862-865. [PMID: 38130022 DOI: 10.1111/jcpp.13940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/08/2023] [Indexed: 12/23/2023]
Abstract
Clinical trials of pharmacological candidates targeting the core features of autism have largely failed. This is despite evidence linking differences in multiple neurochemical systems to brain function in autism. While this has in part been explained by the heterogeneity of the autistic population, the field has largely relied upon association studies to link brain chemistry to function. The only way to directly establish that a neurotransmitter or neuromodulator is involved in a candidate brain function is to change it and observe a shift in that function. This experimental approach dominates preclinical neuroscience, but not human studies. There is little direct experimental evidence describing how neurochemical systems modulate information processing in the living human brain. Thus, our understanding of how neurochemical differences contribute to neurodiversity is limited, impeding our ability to translate findings from animal studies into humans. Here, we introduce our 'shiftability' paradigm, an approach to bridge the translational gap in autism research. We provide an overview of the guiding principles and methodologies we use to directly test the hypothesis that neurochemical systems function differently in autistic and non-autistic individuals.
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Affiliation(s)
- Tobias P Whelan
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- COMPASS Pathfinder Ltd, London, UK
| | - Eileen Daly
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Nicolaas A Puts
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | | | - Declan G M Murphy
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- NIHR-Maudsley Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and the Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Grainne M McAlonan
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- NIHR-Maudsley Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and the Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Fan L, Liang L, Wang Y, Ma X, Yuan L, Ouyang L, He Y, Li Z, Li C, Chen X, Palaniyappan L. Glutamatergic basis of antipsychotic response in first-episode psychosis: a dual voxel study of the anterior cingulate cortex. Neuropsychopharmacology 2024; 49:845-853. [PMID: 37752221 PMCID: PMC10948866 DOI: 10.1038/s41386-023-01741-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/31/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023]
Abstract
A subgroup of patients with schizophrenia is believed to have aberrant excess of glutamate in the frontal cortex; this subgroup is thought to show poor response to first-line antipsychotic treatments that focus on dopamine blockade. If we can identify this subgroup early in the course of illness, we can reduce the repeated use of first-line antipsychotics and potentially stratify first-episode patients to intervene early with second-line treatments such as clozapine. The use of proton magnetic resonance spectroscopy (1H-MRS) to measure glutamate and Glx (glutamate plus glutamine) may provide a means for such a stratification. We must first establish if there is robust evidence linking elevations in anterior cingulate cortex (ACC) glutamate metabolites to poor response, and determine if the use of antipsychotics worsens the glutamatergic excess in eventual nonresponders. In this study, we estimated glutamate levels at baseline in 42 drug-naive patients with schizophrenia. We then treated them all with risperidone at a standard dose range of 2-6 mg/day and followed them up for 3 months to categorize their response status. We expected to see baseline "hyperglutamatergia" in nonresponders, and expected this to worsen over time at the follow-up. In line with our predictions, nonresponders had higher glutamate than responders, but patients as a group did not differ in glutamate and Glx from the healthy control (HC) group before treatment-onset (F1,79 = 3.20, p = 0.046, partial η2 = 0.075). Glutamatergic metabolites did not change significantly over time in both nonresponders and responders over the 3 months of antipsychotic exposure (F1,31 = 1.26, p = 0.270, partial η2 = 0.039). We conclude that the use of antipsychotics without prior knowledge of later response delays symptom relief in a subgroup of first-episode patients, but does not worsen the glutamatergic excess seen at the baseline. Given the current practice of nonstratified use of antipsychotics, longer-time follow-up MRS studies are required to see if improvement in symptoms accompanies a dynamic shift in glutamate profile.
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Affiliation(s)
- Lejia Fan
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Liangbing Liang
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Yujue Wang
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xiaoqian Ma
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Liu Yuan
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Lijun Ouyang
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Ying He
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Zongchang Li
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Chunwang Li
- Department of Radiology, Hunan Children's Hospital, Changsha, China
| | - Xiaogang Chen
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China.
| | - Lena Palaniyappan
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada.
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
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Latagliata EC, Orsini C, Cabib S, Biagioni F, Fornai F, Puglisi-Allegra S. Prefrontal Dopamine in Flexible Adaptation to Environmental Changes: A Game for Two Players. Biomedicines 2023; 11:3189. [PMID: 38137410 PMCID: PMC10740496 DOI: 10.3390/biomedicines11123189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/24/2023] Open
Abstract
Deficits in cognitive flexibility have been characterized in affective, anxiety, and neurodegenerative disorders. This paper reviews data, mainly from studies on animal models, that support the existence of a cortical-striatal brain circuit modulated by dopamine (DA), playing a major role in cognitive/behavioral flexibility. Moreover, we reviewed clinical findings supporting misfunctioning of this circuit in Parkinson's disease that could be responsible for some important non-motoric symptoms. The reviewed findings point to a role of catecholaminergic transmission in the medial prefrontal cortex (mpFC) in modulating DA's availability in the nucleus accumbens (NAc), as well as a role of NAc DA in modulating the motivational value of natural and conditioned stimuli. The review section is accompanied by a preliminary experiment aimed at testing weather the extinction of a simple Pavlovian association fosters increased DA transmission in the mpFC and inhibition of DA transmission in the NAc.
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Affiliation(s)
| | - Cristina Orsini
- I.R.C.C.S. Fondazione Santa Lucia, 00143 Rome, Italy; (C.O.); (S.C.)
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
| | - Simona Cabib
- I.R.C.C.S. Fondazione Santa Lucia, 00143 Rome, Italy; (C.O.); (S.C.)
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
| | - Francesca Biagioni
- I.R.C.C.S. Neuromed, Via Atinense 18, 86077 Pozzilli, Italy; (F.B.); (F.F.)
| | - Francesco Fornai
- I.R.C.C.S. Neuromed, Via Atinense 18, 86077 Pozzilli, Italy; (F.B.); (F.F.)
- Department of Translational Research and New Technologies on Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
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