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Zhu L, Meng H, Zhang W, Wang L, Zhao W, Li J, Shafeng N, Sun H, Jiang T, Liu H, Guo Y, Hou S. A pilot exploratory study for analysis of clinical features and plasma catecholamines in blepharospasm. Sci Rep 2025; 15:2471. [PMID: 39833273 PMCID: PMC11747435 DOI: 10.1038/s41598-025-86922-y] [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: 09/11/2024] [Accepted: 01/15/2025] [Indexed: 01/22/2025] Open
Abstract
Blepharospasm (BSP) is a common focal movement disorder linked to the basal ganglia and plasma catecholamines (CAs). This study aimed to analyze clinical characteristics of BSP patients and explore the relationship with plasma CAs. Clinical characteristics, clinician-rated scales, and plasma CAs were recorded, including dopamine (DA), 3-methoxytyramine (3-MT), and the 3-MT/DA ratio. Plasma CA levels were measured using liquid chromatography-tandem mass spectrometry. Clinical features, plasma CAs, and metabolite contents were compared between groups. Spearman's correlation analysis examined the relationship between plasma CA levels, metabolites, and severity of BSP symptoms. We found that dry eye was an independent risk factor for BSP. Coffee consumption history was an independent protective factor against BSP. Compared to healthy controls, patients had increased DA and decreased 3-MT and 3-MT/DA levels. Anxiety severity negatively correlated with 3-MT and 3-MT/DA levels. The decreased 3-MT/DA ratio is more likely to be a potential biomarker of BSP. These findings highlight the importance of abnormal DA metabolism in BSP pathophysiology and suggest that anxiety symptoms may contribute to BSP pathogenesis by affecting CAs, providing new perspectives for future diagnosis, treatment, and prognostic evaluation of BSP.
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Affiliation(s)
- Lixia Zhu
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Hongmei Meng
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Wuqiong Zhang
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Lijuan Wang
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Weixuan Zhao
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Jiaai Li
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Nilupaer Shafeng
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Huaiyu Sun
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Ting Jiang
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Huiqing Liu
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Yu Guo
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Shuai Hou
- Department of Neurology, The First Hospital of Jilin University, Changchun, China.
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Jao YN, Chao YJ, Chan JF, Hsu YHH. Mass Spectrometry Analysis of Neurotransmitter Shifting during Neurogenesis and Neurodegeneration of PC12 Cells. Int J Mol Sci 2024; 25:10399. [PMID: 39408728 PMCID: PMC11477332 DOI: 10.3390/ijms251910399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 09/20/2024] [Accepted: 09/24/2024] [Indexed: 10/20/2024] Open
Abstract
Parkinson's disease (PD) affects movement; however, most patients with PD also develop nonmotor symptoms, such as hyposmia, sleep disorder, and depression. Dopamine levels in the brain have a critical influence on movement control, but other neurotransmitters are also involved in the progression of PD. This study analyzed the fluctuation of neurotransmitters in PC12 cells during neurogenesis and neurodegeneration by performing mass spectrometry. We found that the dopaminergic metabolism pathway of PC12 cells developed vigorously during the neuron differentiation process and that the neurotransmitters were metabolized into 3-methoxytyramine, which was released from the cells. The regulation of the intracellular and extracellular concentrations of adenosine indicated that adenine nucleotides were actively utilized in neural differentiation. Moreover, we exposed the differentiated PC12 cells to rotenone, which is a suitable material for modeling PD. The cells exposed to rotenone in the early stage of differentiation exhibited stimulated serotoninergic metabolism, and the contents of the serotoninergic neurotransmitters returned to their normal levels in the late stage of differentiation. Interestingly, the nondifferentiated cells can resist the toxicant rotenone and produce normal dopaminergic metabolites. However, when differentiated neuron cells were exposed to rotenone, they were seriously damaged, leading to a failure to produce dopaminergic neurotransmitters. In the low-dosage damage process, the amino acids that functioned as dopaminergic pathway precursors could not be absorbed by the cells, and dopamine and L-dopa were secreted and unable to be reuptaken to trigger the cell damage.
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Affiliation(s)
| | | | | | - Yuan-Hao Howard Hsu
- Department of Chemistry, Tunghai University, No. 1727, Sec. 4, Taiwan Boulevard, Xitun District, Taichung 40704, Taiwan; (Y.-N.J.); (Y.-J.C.); (J.-F.C.)
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Liu C, Lan C, Chen Y. The use of sertraline to treat an adolescent of dystonia comorbid with major depressive disorder with psychotic features. Neuropsychopharmacol Rep 2024; 44:275-279. [PMID: 37987035 PMCID: PMC10932769 DOI: 10.1002/npr2.12401] [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] [Received: 07/26/2023] [Revised: 10/21/2023] [Accepted: 11/04/2023] [Indexed: 11/22/2023] Open
Abstract
Dystonia is characterized by sustained or intermittent involuntary muscle contractions. Psychiatric symptoms are essential non-motor features of dystonia, and higher risks of depressive and anxiety disorders have been reported. The precedence of psychiatric to motor symptoms in some patients and the dopaminergic and serotonergic system involvement in both the motor and psychiatric aspects suggest these psychiatric disorders may be intrinsic to the neurobiology of dystonia. Nevertheless, psychiatric comorbidities are often construed as secondary reactions to motor disabilities and the negative bio-psycho-social impacts of dystonia, leading to underdiagnosis and undertreatment. Research on antidepressant use in dystonia is scarce, especially in children and adolescents. This report presents a 17-year-old female with dystonia comorbid with depression with psychotic features, whose motor symptoms improved but psychiatric symptoms persisted with dopaminergic pharmacotherapy. Sertraline was finally added 5 years after the onset and successfully managed her psychotic depression without worsening motor symptoms. Early detection, prompt diagnosis, and timely holistic treatment with dopaminergic agents, antidepressants, and psychosocial interventions are critical for the mental health of dystonia patients.
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Affiliation(s)
- Chia‐Chien Liu
- Department of PsychiatryTaichung Veterans General HospitalTaichungTaiwan
| | - Chen‐Chia Lan
- Department of PsychiatryTaichung Veterans General HospitalTaichungTaiwan
| | - Ying‐Sheue Chen
- Department of PsychiatryTaipei Veterans General HospitalTaipeiTaiwan
- Department of PsychiatryChina Medical University HospitalTaichungTaiwan
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Zhu L, Meng H, Zhang W, Xie W, Sun H, Hou S. The pathogenesis of blepharospasm. Front Neurol 2024; 14:1336348. [PMID: 38274886 PMCID: PMC10808626 DOI: 10.3389/fneur.2023.1336348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 12/28/2023] [Indexed: 01/27/2024] Open
Abstract
Blepharospasm is a focal dystonia characterized by involuntary tetanic contractions of the orbicularis oculi muscle, which can lead to functional blindness and loss of independent living ability in severe cases. It usually occurs in adults, with a higher incidence rate in women than in men. The etiology and pathogenesis of this disease have not been elucidated to date, but it is traditionally believed to be related to the basal ganglia. Studies have also shown that this is related to the decreased activity of inhibitory neurons in the cerebral cortex caused by environmental factors and genetic predisposition. Increasingly, studies have focused on the imbalance in the regulation of neurotransmitters, including dopamine, serotonin, and acetylcholine, in blepharospasm. The onset of the disease is insidious, and the misdiagnosis rate is high based on history and clinical manifestations. This article reviews the etiology, epidemiological features, and pathogenesis of blepharospasm, to improve understanding of the disease by neurologists and ophthalmologists.
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Affiliation(s)
- Lixia Zhu
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Hongmei Meng
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Wuqiong Zhang
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Wenjing Xie
- Department of Neurology, The Second Hospital of Jilin University, Changchun, China
| | - Huaiyu Sun
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Shuai Hou
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
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Wang JY, Chen JY, Lian YZ, Zhang WY, Wang MY, Liu RP, Chen LH, Zhang X, Zhu JH. Reduced platelet 5-HT content is associated with rest tremor in Parkinson's disease. Parkinsonism Relat Disord 2023; 108:105314. [PMID: 36739793 DOI: 10.1016/j.parkreldis.2023.105314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 01/25/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Parkinson's disease (PD) is highly heterogeneous in manifestations and pathogenesis. Serotonergic neurotransmitter system dysfunction is frequently implicated in PD tremor. Serotonin (5-HT) content in platelets is highly correlated with that in cerebrospinal fluid. In this study, we aimed to understand whether and how platelet 5-HT content reflects tremor in PD. METHOD A total of 139 Chinese PD patients met with inclusion criteria were recruited. Motor and non-motor scores, and disease severity were evaluated. Patients were classified into subtypes of tremor-dominant (TD) and non-tremor-dominant (NTD). Peripheral platelets were isolated, and platelet 5-HT levels were measured. RESULTS Platelet 5-HT content was lower in PD patients of TD subtype than in NTD subtype. Multifactor risk analysis showed that this lower content was independently associated with the TD phenotype. Platelet 5-HT level was inversely correlated with total tremor score, rest tremor amplitude score, rest tremor constancy score, and index of rest tremor, but not with postural tremor score, and kinetic tremor score. CONCLUSION The cross-sectional study demonstrates that reduced platelet 5-HT content is associated with PD rest tremor. Our results support the involvement of serotonergic disturbance in PD rest tremor and indicate that 5-HT reduction can be manifested in peripheral platelets.
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Affiliation(s)
- Jian-Yong Wang
- Department of Neurology, Institute of Geriatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Preventive Medicine, Institute of Nutrition and Diseases, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jin-Yu Chen
- Department of Neurology, Institute of Geriatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yi-Zhi Lian
- Department of Neurology, Institute of Geriatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Neurology, The Affiliated Yueqing Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Wen-Yuan Zhang
- Department of Neurology, Institute of Geriatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Neurology, The Affiliated Yueqing Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Meng-Yan Wang
- Department of Neurology, Institute of Geriatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Neurology, Medical Community of Linhai First People's Hospital, Taizhou, Zhejiang, China
| | - Rong-Pei Liu
- Department of Neurology, Institute of Geriatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ling-Hao Chen
- Department of Preventive Medicine, Institute of Nutrition and Diseases, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiong Zhang
- Department of Neurology, Institute of Geriatric Neurology, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Preventive Medicine, Institute of Nutrition and Diseases, Wenzhou Medical University, Wenzhou, Zhejiang, China.
| | - Jian-Hong Zhu
- Department of Preventive Medicine, Institute of Nutrition and Diseases, Wenzhou Medical University, Wenzhou, Zhejiang, China.
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Gut Microbiome Composition in Dystonia Patients. Int J Mol Sci 2023; 24:ijms24032383. [PMID: 36768705 PMCID: PMC9916458 DOI: 10.3390/ijms24032383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/17/2023] [Accepted: 01/21/2023] [Indexed: 01/27/2023] Open
Abstract
Dystonia is a movement disorder in which patients have involuntary abnormal movements or postures. Non-motor symptoms, such as psychiatric symptoms, sleep problems and fatigue, are common. We hypothesise that the gut microbiome might play a role in the pathophysiology of the (non-)motor symptoms in dystonia via the gut-brain axis. This exploratory study investigates the composition of the gut microbiome in dystonia patients compared to healthy controls. Furthermore, the abundance of neuro-active metabolic pathways, which might be implicated in the (non-)motor symptoms, was investigated. We performed both metagenomic and 16S rRNA sequencing on the stool samples of three subtypes of dystonia (27 cervical dystonia, 20 dopa-responsive dystonia and 24 myoclonus-dystonia patients) and 25 controls. While microbiome alpha and beta diversity was not different between dystonia patients and controls, dystonia patients had higher abundances of Ruminococcus torques and Dorea formicigenerans, and a lower abundance of Butyrivibrio crossotus compared to controls. For those with dystonia, non-motor symptoms and the levels of neurotransmitters in plasma explained the variance in the gut microbiome composition. Several neuro-active metabolic pathways, especially tryptophan degradation, were less abundant in the dystonia patients compared to controls. This suggest that the gut-brain axis might be involved in the pathophysiology of dystonia. Further studies are necessary to confirm our preliminary findings.
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Timmers ER, Plösch T, Smit M, Hof IH, Verkaik-Schakel RN, Tijssen MAJ, de Koning TJ, Niezen-Koning KE. Methylation of the serotonin reuptake transporter gene and non-motor symptoms in dystonia patients. Clin Epigenetics 2022; 14:170. [PMID: 36503539 PMCID: PMC9743677 DOI: 10.1186/s13148-022-01384-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 11/21/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Dystonia is a rare movement disorder, in which patients suffer from involuntary twisting movements or abnormal posturing. Next to these motor symptoms, patients have a high prevalence of psychiatric comorbidity, suggesting a role for serotonin in its pathophysiology. This study investigates the percentage of DNA methylation of the gene encoding for the serotonin reuptake transporter (SLC6A4) in dystonia patients and the associations between methylation levels and presence and severity of psychiatric symptoms. METHODS Patients with cervical dystonia (n = 49), myoclonus dystonia (n = 41) and dopa-responsive dystonia (DRD) (n = 27) and a group of healthy controls (n = 56) were included. Psychiatric comorbidity was evaluated with validated questionnaires. Methylation levels of 20 CpG sites situated 69 to 213 base pairs upstream of the start codon of SLC6A4 were investigated. Methylation in dystonia patients was compared to healthy controls, correcting for age, and correlated with psychiatric comorbidity. RESULTS Bootstrapped quantile regression analysis showed that being a dystonia patient compared to a healthy control significantly explains the methylation level at two CpG sites (CpG 24: pseudo-R2 = 0.05, p = 0.04, CpG 32: pseudo-R2 = 0.14, p = 0.03). Subgroup analysis revealed that being a DRD patient significantly explained a part of the variance of methylation levels at two CpG sites (CpG 21: pseudo-R2 = 0.03, p = 0.00, CpG 24: pseudo-R2 = 0.06, p = 0.03). Regression analysis showed that methylation level at CpG 38 significantly explained a small proportion of the variance of severity score for anxiety (R2 = 0.07, p = 0.04) and having a diagnosis of depression (Nagelkerke R2: 0.11, p = 0.00). Genotype of the 5-HTTLPR polymorphism had no additional effect on these associations. CONCLUSIONS This study showed an association between percentage of methylation at several specific sites of the promoter region of SLCA64 and (dopa-responsive) dystonia patients compared to healthy controls. Furthermore, methylation levels were associated with severity of anxiety and presence of a depressive disorder in the dystonia group. This study suggests alterations in the serotonergic metabolism in dystonia patients, and its relation with the non-motor symptoms.
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Affiliation(s)
- Elze R. Timmers
- grid.4830.f0000 0004 0407 1981Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands ,grid.4494.d0000 0000 9558 4598Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), PO Box 30.001, 9700 RB Groningen, The Netherlands
| | - Torsten Plösch
- grid.4830.f0000 0004 0407 1981Department of Obstetrics and Gynecology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marenka Smit
- grid.4830.f0000 0004 0407 1981Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands ,grid.4494.d0000 0000 9558 4598Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), PO Box 30.001, 9700 RB Groningen, The Netherlands
| | - Ingrid H. Hof
- grid.4494.d0000 0000 9558 4598Laboratory of Metabolic Diseases, Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands
| | - Rikst Nynke Verkaik-Schakel
- grid.4830.f0000 0004 0407 1981Department of Obstetrics and Gynecology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marina A. J. Tijssen
- grid.4830.f0000 0004 0407 1981Department of Neurology, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands ,grid.4494.d0000 0000 9558 4598Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), PO Box 30.001, 9700 RB Groningen, The Netherlands
| | - Tom J. de Koning
- grid.4494.d0000 0000 9558 4598Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), PO Box 30.001, 9700 RB Groningen, The Netherlands ,grid.4514.40000 0001 0930 2361Pediatrics, Department of Clinical Sciences, Lund University, Box 117, 221 00 Lund, Sweden
| | - Klary E. Niezen-Koning
- grid.4494.d0000 0000 9558 4598Expertise Center Movement Disorders Groningen, University Medical Center Groningen (UMCG), PO Box 30.001, 9700 RB Groningen, The Netherlands ,grid.4494.d0000 0000 9558 4598Laboratory of Metabolic Diseases, Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands
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Bailey GA, Martin E, Peall KJ. Cognitive and Neuropsychiatric Impairment in Dystonia. Curr Neurol Neurosci Rep 2022; 22:699-708. [PMID: 36201146 PMCID: PMC9633506 DOI: 10.1007/s11910-022-01233-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2022] [Indexed: 01/27/2023]
Abstract
PURPOSE OF REVIEW To review recent literature evaluating psychiatric and cognitive symptoms in dystonia, the two non-motor symptom groups most frequently evaluated in dystonia research and recognised in clinical practice. RECENT FINDINGS Recent work has embedded clinical recognition of psychiatric symptoms in dystonia, with depressive and anxiety-related symptoms routinely observed to be the most common. Less explored symptoms, such as self-harm, suicidal ideation, and substance abuse, represent newer areas of investigation, with initial work suggesting higher rates than the background population. Investigation of cognitive function has provided less consistent results, both within individual dystonia subtypes and across the spectrum of dystonias, partly reflecting the heterogeneity in approaches to assessment. However, recent work indicates impairments of higher cognitive function, e.g. social cognition, and disrupted visual and auditory sensory processing. Dystonia demonstrates psychiatric and cognitive symptom heterogeneity, with further work needed to recognise endophenotypes and improve diagnostic accuracy, symptom recognition, and management.
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Affiliation(s)
- Grace A Bailey
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Eva Martin
- School of Medicine, Cardiff University, Cardiff, UK
| | - Kathryn J Peall
- Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK.
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Fitzgerald PJ. Are Noradrenergic Transmission Reducing Drugs Antidepressants? Front Behav Neurosci 2021; 15:673634. [PMID: 34658805 PMCID: PMC8514666 DOI: 10.3389/fnbeh.2021.673634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 09/07/2021] [Indexed: 01/08/2023] Open
Abstract
Major depressive disorder (MDD) remains a significant public health problem worldwide, and revised treatment strategies are therefore urgently needed, including the creation of novel antidepressant compounds or using existing molecular entities in new ways. Etiologic theories of MDD from decades ago have suggested that synaptic deficiencies of monoaminergic neurotransmitters play a causative role in this neuropsychiatric disorder, and that boosting monoamines with drugs such as SSRIs, SNRIs, TCAs, and MAOIs has antidepressant effects and in some individuals can even induce hypomania or mania. While other factors, such as various intracellular molecular pathways and hippocampal neurogenesis, undoubtedly also play a role in MDD, monoaminergic boosting drugs nonetheless have clearly demonstrated antidepressant properties. There is also, however, a body of studies in the preclinical literature suggesting that monoaminergic transmission reducing drugs, including noradrenergic ones, also have antidepressant-like behavioral properties in rodents. Given that there is increasing evidence that the monoamines have u-shaped or Janus-faced dose-response properties, in which a mid-range value is "optimal" in a variety of behavioral and physiological processes, it is plausible that either too much or too little synaptic norepinephrine in key circuits may exacerbate MDD in some individuals. Here we briefly review rodent depression-related behavioral data, focusing on the forced swim test, from three major classes of noradrenergic transmission reducing drugs (alpha2 agonists, beta blockers, alpha1 antagonists), and find much support for the hypothesis that they have antidepressant-like properties. Whether these drugs are antidepressants in human subjects remains to be determined.
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Affiliation(s)
- Paul J Fitzgerald
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, United States
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