1
|
Quek DYL, Taylor N, Gilat M, Lewis SJG, Ehgoetz Martens KA. Effect of dopamine on limbic network connectivity at rest in Parkinson's disease patients with freezing of gait. Transl Neurosci 2024; 15:20220336. [PMID: 38708096 PMCID: PMC11066616 DOI: 10.1515/tnsci-2022-0336] [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: 12/22/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 05/07/2024] Open
Abstract
Background Freezing of gait (FOG) in Parkinson's disease (PD) has a poorly understood pathophysiology, which hinders treatment development. Recent work showed a dysfunctional fronto-striato-limbic circuitry at rest in PD freezers compared to non-freezers in the dopamine "OFF" state. While other studies found that dopaminergic replacement therapy alters functional brain organization in PD, the specific effect of dopamine medication on fronto-striato-limbic functional connectivity in freezers remains unclear. Objective To evaluate how dopamine therapy alters resting state functional connectivity (rsFC) of the fronto-striato-limbic circuitry in PD freezers, and whether the degree of connectivity change is related to freezing severity and anxiety. Methods Twenty-three PD FOG patients underwent MRI at rest (rsfMRI) in their clinically defined "OFF" and "ON" dopaminergic medication states. A seed-to-seed based analysis was performed between a priori defined limbic circuitry ROIs. Functional connectivity was compared between OFF and ON states. A secondary correlation analyses evaluated the relationship between Hospital Anxiety and Depression Scale (HADS)-Anxiety) and FOG Questionnaire with changes in rsFC from OFF to ON. Results PD freezers' OFF compared to ON showed increased functional coupling between the right hippocampus and right caudate nucleus, and between the left putamen and left posterior parietal cortex (PPC). A negative association was found between HADS-Anxiety and the rsFC change from OFF to ON between the left amygdala and left prefrontal cortex, and left putamen and left PPC. Conclusion These findings suggest that dopaminergic medication partially modulates the frontoparietal-limbic-striatal circuitry in PD freezers, and that the influence of medication on the amygdala, may be related to clinical anxiety in freezer.
Collapse
Affiliation(s)
- Dione Y. L. Quek
- Parkinson’s Disease Research Clinic, Brain and Mind Centre, University of Sydney, Sydney, Australia
| | - Natasha Taylor
- Parkinson’s Disease Research Clinic, Brain and Mind Centre, University of Sydney, Sydney, Australia
| | - Moran Gilat
- Neurorehabilitation Research Group (eNRGy), Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Simon J. G. Lewis
- Parkinson’s Disease Research Clinic, Brain and Mind Centre, University of Sydney, Sydney, Australia
| | - Kaylena A. Ehgoetz Martens
- Parkinson’s Disease Research Clinic, Brain and Mind Centre, University of Sydney, Sydney, Australia
- Department of Kinesiology and Health Sciences, University of Waterloo, 200 University Avenue West, WaterlooON, N2L3G1Canada
| |
Collapse
|
2
|
Lan C, Liu C, Li K, Zhao Z, Yang J, Ma Y, Scheele D, Yao S, Kendrick KM, Becker B. Oxytocinergic Modulation of Stress-Associated Amygdala-Hippocampus Pathways in Humans Is Mediated by Serotonergic Mechanisms. Int J Neuropsychopharmacol 2022; 25:807-817. [PMID: 35723242 PMCID: PMC9593216 DOI: 10.1093/ijnp/pyac037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/31/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The hypothalamic neuropeptide oxytocin (OXT) may exert anxiolytic and stress-reducing actions via modulatory effects on amygdala circuits. Animal models and initial findings in humans suggest that some of these effects are mediated by interactions with other neurotransmitter systems, in particular the serotonin (5-HT) system. Against this background, the present pharmacological resting-state functional magnetic resonance imaging study aimed to determine whether effects of OXT on stress-associated amygdala intrinsic networks are mediated by 5-HT. METHODS We employed a randomized, placebo-controlled, double-blind parallel-group, pharmacological functional magnetic resonance imaging resting-state experiment with 4 treatment groups in n = 112 healthy male participants. Participants underwent a transient decrease in 5-HT signaling via acute tryptophan depletion (ATD) or a corresponding placebo-control protocol before the administration of intranasal OXT (24 IU) or placebo intranasal spray. RESULTS OXT and 5-HT modulation exerted interactive effects on the coupling of the left amygdala with the ipsilateral hippocampus and adjacent midbrain. OXT increased intrinsic coupling in this pathway, whereas this effect of OXT was significantly attenuated during transiently decreased central serotonergic signaling induced via acute tryptophan depletion. In the absence of OXT or 5-HT modulation, this pathway showed a trend for an association with self-reported stress perception in everyday life. No interactive effects were observed for the right amygdala. CONCLUSIONS Together, the findings provide the first evidence, to our knowledge, that the effects of OXT on stress-associated amygdala-hippocampal-midbrain pathways are critically mediated by the 5-HT system in humans.
Collapse
Affiliation(s)
| | | | - Keshuang Li
- The Clinical Hospital of the Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China,School of Psychology and Cognitive Science, East China Normal University, Shanghai, China
| | - Zhiying Zhao
- The Clinical Hospital of the Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China,Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jiaxin Yang
- State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute of Brain Research, Beijing Normal University, Beijing, China
| | - Yina Ma
- State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute of Brain Research, Beijing Normal University, Beijing, China
| | - Dirk Scheele
- Division of Medical Psychology, Department of Psychiatry and Psychotherapy, University HospitalBonn, Bonn, Germany,Department of Psychiatry, School of Medicine & Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Shuxia Yao
- The Clinical Hospital of the Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Keith M Kendrick
- The Clinical Hospital of the Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Benjamin Becker
- Correspondence: Benjamin Becker, PhD, University of Electronic Science and Technology, Xiyuan Avenue 2006, 611731 Chengdu, China ()
| |
Collapse
|
3
|
Szklany K, Engen PA, Naqib A, Green SJ, Keshavarzian A, Lopez Rincon A, Siebrand CJ, Diks MAP, van de Kaa M, Garssen J, Knippels LMJ, Kraneveld AD. Dietary Supplementation throughout Life with Non-Digestible Oligosaccharides and/or n-3 Poly-Unsaturated Fatty Acids in Healthy Mice Modulates the Gut-Immune System-Brain Axis. Nutrients 2021; 14:173. [PMID: 35011046 PMCID: PMC8746884 DOI: 10.3390/nu14010173] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/20/2021] [Accepted: 12/24/2021] [Indexed: 12/11/2022] Open
Abstract
The composition and activity of the intestinal microbial community structures can be beneficially modulated by nutritional components such as non-digestible oligosaccharides and omega-3 poly-unsaturated fatty acids (n-3 PUFAs). These components affect immune function, brain development and behaviour. We investigated the additive effect of a dietary combination of scGOS:lcFOS and n-3 PUFAs on caecal content microbial community structures and development of the immune system, brain and behaviour from day of birth to early adulthood in healthy mice. Male BALB/cByJ mice received a control or enriched diet with a combination of scGOS:lcFOS (9:1) and 6% tuna oil (n-3 PUFAs) or individually scGOS:lcFOS (9:1) or 6% tuna oil (n-3 PUFAs). Behaviour, caecal content microbiota composition, short-chain fatty acid levels, brain monoamine levels, enterochromaffin cells and immune parameters in the mesenteric lymph nodes (MLN) and spleen were assessed. Caecal content microbial community structures displayed differences between the control and dietary groups, and between the dietary groups. Compared to control diet, the scGOS:lcFOS and combination diets increased caecal saccharolytic fermentation activity. The diets enhanced the number of enterochromaffin cells. The combination diet had no effects on the immune cells. Although the dietary effect on behaviour was limited, serotonin and serotonin metabolite levels in the amygdala were increased in the combination diet group. The combination and individual interventions affected caecal content microbial profiles, but had limited effects on behaviour and the immune system. No apparent additive effect was observed when scGOS:lcFOS and n-3 PUFAs were combined. The results suggest that scGOS:lcFOS and n-3 PUFAs together create a balance-the best of both in a healthy host.
Collapse
Affiliation(s)
- Kirsten Szklany
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
| | - Phillip A. Engen
- Rush Center for Integrated Microbiome and Chronobiology Research, Rush Medical College, Rush University Medical Center, Chicago, IL 60602, USA; (P.A.E.); (A.N.); (A.K.)
| | - Ankur Naqib
- Rush Center for Integrated Microbiome and Chronobiology Research, Rush Medical College, Rush University Medical Center, Chicago, IL 60602, USA; (P.A.E.); (A.N.); (A.K.)
| | - Stefan J. Green
- Genomics and Microbiome Core Facility, Rush University Medical Center, Chicago, IL 60602, USA;
| | - Ali Keshavarzian
- Rush Center for Integrated Microbiome and Chronobiology Research, Rush Medical College, Rush University Medical Center, Chicago, IL 60602, USA; (P.A.E.); (A.N.); (A.K.)
- Department of Medicine & Physiology, Rush University Medical Center, Chicago, IL 60602, USA
| | - Alejandro Lopez Rincon
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
- Department of Data Science, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, 3584 EA Utrecht, The Netherlands
| | - Cynthia J. Siebrand
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
| | - Mara A. P. Diks
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
| | - Melanie van de Kaa
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
| | - Johan Garssen
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
- Global Centre of Excellence Immunology, Nutricia Danone Research, 3584 CT Utrecht, The Netherlands
| | - Leon M. J. Knippels
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
- Global Centre of Excellence Immunology, Nutricia Danone Research, 3584 CT Utrecht, The Netherlands
| | - Aletta D. Kraneveld
- Division of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands; (K.S.); (A.L.R.); (C.J.S.); (M.A.P.D.); (M.v.d.K.); (J.G.); (L.M.J.K.)
| |
Collapse
|
4
|
Long-term variable photoperiod exposure impairs the mPFC and induces anxiety and depression-like behavior in male wistar rats. Exp Neurol 2021; 347:113908. [PMID: 34710402 DOI: 10.1016/j.expneurol.2021.113908] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 10/07/2021] [Accepted: 10/23/2021] [Indexed: 01/15/2023]
Abstract
Long-term shift work can cause circadian misalignment, which has been linked to anxiety and depression. However, the associated pathophysiologic changes have not been described in detail, and the mechanism underlying this association is not fully understood. To address these points, we used a rat model of CM induced by long-term variable photoperiod exposure [L-VP] (ie, for 90 days). We compared the numbers of neurons, astrocytes, and dendritic spines; dendrite morphology; long-term potentiation (LTP), long-term depression (LTD) and paired-pulse ratio (PPR); expression of glutamate receptor [N-methyl-d-aspartate receptor (NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)] subunits and brain-derived neurotrophic factor (BDNF) in the medial prefrontal cortex (mPFC); and the anxiety and depression behaviors between rats in the circadian misalignment (CM) and circadian alignment (CA, with normal circadian rhythm) groups. The results showed that L-VP reduced the number of neurons and astrocytes in the mPFC and decreased the number of dendritic spines, dendrite complexity, LTP, LTD, PPR, and expression of glutamate receptors (GluR1, GluR2, GluR3, NMDAR2A, and NMDAR2B) and BDNF in the mPFC. L-VP also induced anxiety and depression-like behaviors, as measured by the open field test, elevated plus-maze, sucrose preference test, and forced swim test. These results suggest that CM induces a loss of neurons and astrocytes and synaptic damage in surviving pyramidal cells in the mPFC might be involved in the pathophysiology of anxiety and depression.
Collapse
|
5
|
The Modulatory Role of Serotonin on Human Impulsive Aggression. Biol Psychiatry 2021; 90:447-457. [PMID: 34266672 DOI: 10.1016/j.biopsych.2021.05.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/29/2021] [Accepted: 05/16/2021] [Indexed: 12/15/2022]
Abstract
The hypothesis of chronically low brain serotonin levels as pathophysiologically linked to impulsive aggression has been around for several decades. Whereas the theory was initially based on indirect methods to probe serotonin function, our understanding of the neural mechanisms involved in impulsive aggression has progressed with recent advances in neuroimaging. The review integrates evidence based on data from several neuroimaging domains in humans. In vivo molecular neuroimaging findings demonstrate associations between impulsive aggression and high serotonin 1B and serotonin 4 receptor binding, high serotonin transporter levels, and low monoamine oxidase A levels, suggesting that low interstitial serotonin levels are a neurobiological risk factor for impulsive aggressive behavior. Imaging genetics suggests that serotonergic-related genetic polymorphisms associate with antisocial behavior, and some evidence indicates that the low-expressing monoamine oxidase A genotype specifically predisposes to impulsive aggression, which may be mediated by effects on corticolimbic function. Interventions that (presumably) alter serotonin levels have effects on brain activity within brain regions involved in impulsive aggression, notably the amygdala, dorsal striatum, anterior cingulate, insula, and prefrontal cortex. Based on these findings, we propose a model for the modulatory role of serotonin in impulsive aggression. Future studies should ensure that clinical features unique for impulsive aggression are appropriately assessed, and we propose investigations of knowledge gaps that can help confirm, refute, or modify our proposed model of impulsive aggression.
Collapse
|
6
|
Metabolic changes in the brain and blood of rats following acoustic trauma, tinnitus and hyperacusis. PROGRESS IN BRAIN RESEARCH 2021; 262:399-430. [PMID: 33931189 DOI: 10.1016/bs.pbr.2020.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It has been increasingly recognized that tinnitus is likely to be generated by complex network changes. Acoustic trauma that causes tinnitus induces significant changes in multiple metabolic pathways in the brain. However, it is not clear whether those metabolic changes in the brain could also be reflected in blood samples and whether metabolic changes could discriminate acoustic trauma, hyperacusis and tinnitus. We analyzed brain and serum metabolic changes in rats following acoustic trauma or a sham procedure using metabolomics. Hearing levels were recorded before and after acoustic trauma and behavioral measures to quantify tinnitus and hyperacusis were conducted at 4 weeks following acoustic trauma. Tissues from 11 different brain regions and serum samples were collected at about 3 months following acoustic trauma. Among the acoustic trauma animals, eight exhibited hyperacusis-like behavior and three exhibited tinnitus-like behavior. Using Gas chromatography-mass spectrometry and multivariate statistical analysis, significant metabolic changes were found in acoustic trauma animals in both the brain and serum samples with a number of metabolic pathways significantly perturbated. Furthermore, metabolic changes in the serum were able to differentiate sham from acoustic trauma animals, as well as sham from hyperacusis animals, with high accuracy. Our results suggest that serum metabolic profiling in combination with machine learning analysis may be a promising approach for identifying biomarkers for acoustic trauma, hyperacusis and potentially, tinnitus.
Collapse
|
7
|
Baeken C, Xu Y, Wu GR, Dockx R, Peremans K, De Raedt R. Hostility in medication-resistant major depression and comorbid generalized anxiety disorder is related to increased hippocampal-amygdala 5-HT 2A receptor density. Eur Arch Psychiatry Clin Neurosci 2021; 271:1369-1378. [PMID: 33904978 PMCID: PMC8429407 DOI: 10.1007/s00406-021-01243-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 02/24/2021] [Indexed: 11/03/2022]
Abstract
Major depressive disorder (MDD) and generalized anxiety disorder (GAD) are severe and difficult-to-treat psychiatric illnesses with high rates of comorbidity. Although both disorders are treated with serotonergic based psychotropic agents, little is known on the influence of the serotonergic neurotransmitter system on the occurrence of comorbid GAD when clinically depressed. To investigate this poorly understood clinical question, we examined the involvement of frontolimbic post-synaptic 5-HT2A receptors in 20 medication-resistant depressed (MRD) patients with half of them diagnosed with comorbid GAD with 123I-5-I-R91150 SPECT. To explore whether 5-HT2A receptor-binding indices (BI) associated with comorbid GAD could be related to distinct psychopathological symptoms, all were assessed with the symptom Checklist-90-Revised (SCL-90-R). MRD patients with comorbid GAD displayed significantly higher 5-HT2A receptor BI in the hippocampal-amygdala complex, compared to MRD patients without GAD. Correlation analyses revealed that the 5-HT2A receptor BI in these areas were significantly related to the SCL-90-R subscale hostility (HOS), especially for those MRD patients with comorbid GAD. Comorbid MRD-GAD may be characterized with increased hippocampal-amygdala 5-HT2A receptor BI which could represent enhanced levels in hostility in such kinds of patients. Adapted psychotherapeutic interventions may be warranted.
Collapse
Affiliation(s)
- Chris Baeken
- grid.5342.00000 0001 2069 7798Department of Psychiatry and Medical Psychology, Ghent Experimental Psychiatry (GHEP) Lab, Ghent University, Ghent, Belgium ,grid.8767.e0000 0001 2290 8069Department of Psychiatry, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZBrussel), Laarbeeklaan 101, 1090 Brussels, Belgium ,grid.6852.90000 0004 0398 8763Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Yanfeng Xu
- grid.5342.00000 0001 2069 7798Department of Psychiatry and Medical Psychology, Ghent Experimental Psychiatry (GHEP) Lab, Ghent University, Ghent, Belgium ,grid.5342.00000 0001 2069 7798Department of Veterinary Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Guo-Rong Wu
- Key Laboratory of Cognition and Personality, Faculty of Psychology, Southwest University, Chongqing, China.
| | - Robrecht Dockx
- grid.5342.00000 0001 2069 7798Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Kathelijne Peremans
- grid.5342.00000 0001 2069 7798Department of Veterinary Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Rudi De Raedt
- grid.5342.00000 0001 2069 7798Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| |
Collapse
|
8
|
Psychedelic drugs: neurobiology and potential for treatment of psychiatric disorders. Nat Rev Neurosci 2020; 21:611-624. [PMID: 32929261 DOI: 10.1038/s41583-020-0367-2] [Citation(s) in RCA: 195] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2020] [Indexed: 12/13/2022]
Abstract
Renewed interest in the use of psychedelics in the treatment of psychiatric disorders warrants a better understanding of the neurobiological mechanisms underlying the effects of these substances. After a hiatus of about 50 years, state-of-the art studies have recently begun to close important knowledge gaps by elucidating the mechanisms of action of psychedelics with regard to their effects on receptor subsystems, systems-level brain activity and connectivity, and cognitive and emotional processing. In addition, functional studies have shown that changes in self-experience, emotional processing and social cognition may contribute to the potential therapeutic effects of psychedelics. These discoveries provide a scientific road map for the investigation and application of psychedelic substances in psychiatry.
Collapse
|
9
|
Trait Anxiety Mediated by Amygdala Serotonin Transporter in the Common Marmoset. J Neurosci 2020; 40:4739-4749. [PMID: 32393533 DOI: 10.1523/jneurosci.2930-19.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/06/2020] [Accepted: 03/19/2020] [Indexed: 01/04/2023] Open
Abstract
High trait anxiety is associated with altered activity across emotion regulation circuitry and a higher risk of developing anxiety disorders and depression. This circuitry is extensively modulated by serotonin. Here, to understand why some people may be more vulnerable to developing affective disorders, we investigated whether serotonin-related gene expression across the brain's emotion regulation circuitry may underlie individual differences in trait anxiety using the common marmoset (Callithrix jacchus, mixed sexes) as a model. First, we assessed the association of region-specific expression of the serotonin transporter (SLC6A4) and serotonin receptor (HTR1A, HTR2A, HTR2C) genes with anxiety-like behavior; and second, we investigated their causal role in two key features of the high trait anxious phenotype: high responsivity to anxiety-provoking stimuli and an exaggerated conditioned threat response. While the expression of the serotonin receptors did not show a significant relationship with anxiety-like behavior in any of the targeted brain regions, serotonin transporter expression, specifically within the right ventrolateral prefrontal cortex (vlPFC) and most strongly in the right amygdala, was associated positively with anxiety-like behavior. The causal relationship between amygdala serotonin levels and an animal's sensitivity to threat was confirmed via direct amygdala infusions of a selective serotonin reuptake inhibitor (SSRI), citalopram. Both anxiety-like behaviors, and conditioned threat-induced responses were reduced by the blockade of serotonin reuptake in the amygdala. Together, these findings provide evidence that high amygdala serotonin transporter expression contributes to the high trait anxious phenotype and suggest that reduction of threat reactivity by SSRIs may be mediated by their actions in the amygdala.SIGNIFICANCE STATEMENT Findings here contribute to our understanding of how the serotonin system underlies an individual's expression of threat-elicited negative emotions such as anxiety and fear within nonhuman primates. Exploration of serotonergic gene expression across brain regions implicated in emotion regulation revealed that serotonin transporter gene expression in the ventrolateral prefrontal cortex (vlPFC) and most strongly in the amygdala, but none of the serotonin receptor genes, were predictive of interindividual differences in anxiety-like behavior. Targeting of amygdala serotonin reuptake with selective serotonin reuptake inhibitors (SSRIs) confirmed the causal relationship between amygdala serotonin transporter and an animal's sensitivity to threat by reversing expression of two key features of the high trait-like anxiety phenotype: high responsivity to anxiety-provoking uncertain threat and responsivity to certain conditioned threat.
Collapse
|
10
|
Zheng Y, McTavish J, Smith PF. Pharmacological Evaluation of Drugs in Animal Models of Tinnitus. Curr Top Behav Neurosci 2020; 51:51-82. [PMID: 33590458 DOI: 10.1007/7854_2020_212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Despite the pressing need for effective drug treatments for tinnitus, currently, there is no single drug that is approved by the FDA for this purpose. Instead, a wide range of unproven over-the-counter tinnitus remedies are available on the market with little or no benefit for tinnitus but with potential harm and adverse effects. Animal models of tinnitus have played a critical role in exploring the pathophysiology of tinnitus, identifying therapeutic targets and evaluating novel and existing drugs for tinnitus treatment. This review summarises and compares the studies on pharmacological evaluation of tinnitus treatment in different animal models based on the pharmacological properties of the drug and provides insights into future directions for tinnitus drug discovery.
Collapse
Affiliation(s)
- Yiwen Zheng
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand. .,Brain Research New Zealand, Auckland, New Zealand. .,Brain Health Research Centre, University of Otago, Dunedin, New Zealand. .,Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand.
| | - Jessica McTavish
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand, Auckland, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
| | - Paul F Smith
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand, Auckland, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
| |
Collapse
|
11
|
Nees F, Witt SH, Flor H. Neurogenetic Approaches to Stress and Fear in Humans as Pathophysiological Mechanisms for Posttraumatic Stress Disorder. Biol Psychiatry 2018; 83:810-820. [PMID: 29454655 DOI: 10.1016/j.biopsych.2017.12.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 12/19/2017] [Accepted: 12/22/2017] [Indexed: 11/28/2022]
Abstract
In this review article, genetic variation associated with brain responses related to acute and chronic stress reactivity and fear learning in humans is presented as an important mechanism underlying posttraumatic stress disorder. We report that genes related to the regulation of the hypothalamic-pituitary-adrenal axis, as well as genes that modulate serotonergic, dopaminergic, and neuropeptidergic functions or plasticity, play a role in this context. The strong overlap of the genetic targets involved in stress and fear learning suggests that a dimensional and mechanistic model of the development of posttraumatic stress disorder based on these constructs is promising. Genome-wide genetic analyses on fear and stress mechanisms are scarce. So far, reliable replication is still lacking for most of the molecular genetic findings, and the proportion of explained variance is rather small. Further analysis of neurogenetic stress and fear learning needs to integrate data from animal and human studies.
Collapse
Affiliation(s)
- Frauke Nees
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stephanie H Witt
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Herta Flor
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Psychology, School of Social Sciences, University of Mannheim, Mannheim, Germany.
| |
Collapse
|
12
|
da Cunha-Bang S, Fisher PM, Hjordt LV, Perfalk E, Beliveau V, Holst K, Knudsen GM. Men with high serotonin 1B receptor binding respond to provocations with heightened amygdala reactivity. Neuroimage 2018; 166:79-85. [DOI: 10.1016/j.neuroimage.2017.10.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/12/2017] [Accepted: 10/16/2017] [Indexed: 10/18/2022] Open
|
13
|
Testosterone levels in healthy men correlate negatively with serotonin 4 receptor binding. Psychoneuroendocrinology 2017; 81:22-28. [PMID: 28426945 DOI: 10.1016/j.psyneuen.2017.03.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/14/2017] [Indexed: 12/20/2022]
Abstract
The serotonergic system integrates sex steroid information and plays a central role in mood and stress regulation, cognition, appetite and sleep. This interplay may be critical for likelihood of developing depressive episodes, at least in a subgroup of sensitive individuals. The serotonin 4 receptor (5-HT4R) indexes central serotonergic tonus, which may be related to endogenous sex-steroid levels in the mentally healthy state even though this remains elusive. Here we evaluate if peripheral levels of estradiol and testosterone are associated with 5-HT4R binding as imaged by [11C]SB207145 positron emission tomography in a group of 41 healthy men. We estimated global 5-HT4R binding using a latent variable model framework, which models shared correlation between 5-HT4R across multiple brain regions (hippocampus, amygdala, posterior and anterior cingulate, thalamus, pallidostriatum and neocortex). We tested whether testosterone and estradiol predict global 5-HT4R, adjusting for age. We found that testosterone, but not estradiol, correlated negatively with global 5-HT4R levels (p=0.02) suggesting that men with high levels of testosterone have higher cerebral serotonergic tonus. Our findings corroborate the link between sex hormone levels and serotonin signalling. Future longitudinal studies in clinical relevant populations are needed to elucidate the potential importance of testosterone in the pathophysiology of e.g. major depression and its treatment.
Collapse
|
14
|
Raab K, Kirsch P, Mier D. Understanding the impact of 5-HTTLPR, antidepressants, and acute tryptophan depletion on brain activation during facial emotion processing: A review of the imaging literature. Neurosci Biobehav Rev 2016; 71:176-197. [DOI: 10.1016/j.neubiorev.2016.08.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 07/28/2016] [Accepted: 08/26/2016] [Indexed: 12/22/2022]
|
15
|
Waltz JA. The neural underpinnings of cognitive flexibility and their disruption in psychotic illness. Neuroscience 2016; 345:203-217. [PMID: 27282085 DOI: 10.1016/j.neuroscience.2016.06.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/25/2016] [Accepted: 06/03/2016] [Indexed: 12/27/2022]
Abstract
Schizophrenia (SZ) has long been associated with a variety of cognitive deficits, including reduced cognitive flexibility. More recent findings, however, point to tremendous inter-individual variability among patients on measures of cognitive flexibility/set-shifting. With an eye toward shedding light on potential sources of variability in set-shifting abilities among SZ patients, I examine the neural substrates of underlying probabilistic reversal learning (PRL) - a paradigmatic measure of cognitive flexibility - as well as neuromodulatory influences upon these systems. Finally, I report on behavioral and neuroimaging studies of PRL in SZ patients, discussing the potentially influences of illness profile and antipsychotic medications on cognitive flexibility in SZ.
Collapse
Affiliation(s)
- James A Waltz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
16
|
Developmental psychopathology in an era of molecular genetics and neuroimaging: A developmental neurogenetics approach. Dev Psychopathol 2016; 27:587-613. [PMID: 25997774 DOI: 10.1017/s0954579415000188] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The emerging field of neurogenetics seeks to model the complex pathways from gene to brain to behavior. This field has focused on imaging genetics techniques that examine how variability in common genetic polymorphisms predict differences in brain structure and function. These studies are informed by other complimentary techniques (e.g., animal models and multimodal imaging) and have recently begun to incorporate the environment through examination of Imaging Gene × Environment interactions. Though neurogenetics has the potential to inform our understanding of the development of psychopathology, there has been little integration between principles of neurogenetics and developmental psychopathology. The paper describes a neurogenetics and Imaging Gene × Environment approach and how these approaches have been usefully applied to the study of psychopathology. Six tenets of developmental psychopathology (the structure of phenotypes, the importance of exploring mechanisms, the conditional nature of risk, the complexity of multilevel pathways, the role of development, and the importance of who is studied) are identified, and how these principles can further neurogenetics applications to understanding the development of psychopathology is discussed. A major issue of this piece is how neurogenetics and current imaging and molecular genetics approaches can be incorporated into developmental psychopathology perspectives with a goal of providing models for better understanding pathways from among genes, environments, the brain, and behavior.
Collapse
|
17
|
Sumner JA, Powers A, Jovanovic T, Koenen KC. Genetic influences on the neural and physiological bases of acute threat: A research domain criteria (RDoC) perspective. Am J Med Genet B Neuropsychiatr Genet 2016; 171B:44-64. [PMID: 26377804 PMCID: PMC4715467 DOI: 10.1002/ajmg.b.32384] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/01/2015] [Indexed: 01/13/2023]
Abstract
The NIMH Research Domain Criteria (RDoC) initiative aims to describe key dimensional constructs underlying mental function across multiple units of analysis-from genes to observable behaviors-in order to better understand psychopathology. The acute threat ("fear") construct of the RDoC Negative Valence System has been studied extensively from a translational perspective, and is highly pertinent to numerous psychiatric conditions, including anxiety and trauma-related disorders. We examined genetic contributions to the construct of acute threat at two units of analysis within the RDoC framework: (1) neural circuits and (2) physiology. Specifically, we focused on genetic influences on activation patterns of frontolimbic neural circuitry and on startle, skin conductance, and heart rate responses. Research on the heritability of activation in threat-related frontolimbic neural circuitry is lacking, but physiological indicators of acute threat have been found to be moderately heritable (35-50%). Genetic studies of the neural circuitry and physiology of acute threat have almost exclusively relied on the candidate gene method and, as in the broader psychiatric genetics literature, most findings have failed to replicate. The most robust support has been demonstrated for associations between variation in the serotonin transporter (SLC6A4) and catechol-O-methyltransferase (COMT) genes with threat-related neural activation and physiological responses. However, unbiased genome-wide approaches using very large samples are needed for gene discovery, and these can be accomplished with collaborative consortium-based research efforts, such as those of the Psychiatric Genomics Consortium (PGC) and Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) Consortium.
Collapse
Affiliation(s)
- Jennifer A Sumner
- Center for Behavioral Cardiovascular Health, Columbia University Medical Center, New York, New York
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Abigail Powers
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia
| | - Tanja Jovanovic
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia
| | - Karestan C Koenen
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Psychiatric and Neurodevelopmental Genetics Unit and Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts
- The Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| |
Collapse
|
18
|
Challis C, Berton O. Top-Down Control of Serotonin Systems by the Prefrontal Cortex: A Path toward Restored Socioemotional Function in Depression. ACS Chem Neurosci 2015; 6:1040-54. [PMID: 25706226 DOI: 10.1021/acschemneuro.5b00007] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Social withdrawal, increased threat perception, and exaggerated reassurance seeking behaviors are prominent interpersonal symptoms in major depressive disorder (MDD). Altered serotonin (5-HT) systems and corticolimbic dysconnectivity have long been suspected to contribute to these symptomatic facets; however, the underlying circuits and intrinsic cellular mechanisms that control 5-HT output during socioemotional interactions remain poorly understood. We review literature that implicates a direct pathway between the ventromedial prefrontal cortex (vmPFC) and dorsal raphe nucleus (DRN) in the adaptive and pathological control of social approach-avoidance behaviors. Imaging and neuromodulation during approach-avoidance tasks in humans point to the cortical control of brainstem circuits as an essential regulator of socioemotional decisions and actions. Parallel rodent studies using viral-based connectomics and optogenetics are beginning to provide a cellular blueprint of the underlying circuitry. In these studies, manipulations of vmPFC synaptic inputs to the DRN have revealed bidirectional influences on socioaffective behaviors via direct monosynaptic excitation and indirect disynaptic inhibition of 5-HT neurons. Additionally, adverse social experiences that result in permanent avoidance biases, such as social defeat, drive long-lasting plasticity in this microcircuit, potentiating the indirect inhibition of 5-HT output. Conversely, neuromodulation of the vmPFC via deep brain stimulation (DBS) attenuates avoidance biases by restoring the direct excitatory drive of 5-HT neurons and strengthening a key subset of forebrain 5-HT projections. Better understanding the cellular organization of the vmPFC-DRN pathway and identifying molecular determinants of its neuroplasticity can open fundamentally novel avenues for the treatment of affective disorders.
Collapse
Affiliation(s)
- Collin Challis
- Department of Psychiatry, ‡Neuroscience Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, United States
| | - Olivier Berton
- Department of Psychiatry, ‡Neuroscience Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
19
|
Agorastos A, Kellner M, Stiedl O, Muhtz C, Wiedemann K, Demiralay C. Blunted autonomic reactivity to pharmacological panic challenge under long-term escitalopram treatment in healthy men. Int J Neuropsychopharmacol 2014; 18:pyu053. [PMID: 25522396 PMCID: PMC4376541 DOI: 10.1093/ijnp/pyu053] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Central serotonergic pathways influence brain areas involved in vagal cardiovascular regulation and, thereby, influence sympathetic efferent activity. Selective serotonin reuptake inhibitors (SSRIs) affect multiple serotonergic pathways, including central autonomic pathways. However, only a few studies have assessed SSRI-mediated effects on autonomic reactivity in healthy individuals using heart rate variability (HRV). METHODS The present study assessed the influence of long-term treatment with escitalopram (ESC) on autonomic reactivity to an intravenous application of 50 µg cholecystokinin tetrapeptide (CCK-4) in 30 healthy young men using a double-blind, placebo (PLA)-controlled, randomized, within-subject cross-over design. Main outcome measures were time- and frequency-domain HRV parameters, assessed at both baseline and immediately after CCK-4 application. RESULTS Results showed substantial effects for the treatment × CCK-4 challenge interaction with respect to heart rate (p < 0.001; pη(2) = 0.499), SDNN (p < 0.001; pη(2) = 576), RMSSD (p = 0.015; pη(2) = 194), NN50% (p = 0.008; pη(2) = 0.224), and LF% (p = 0.014; pη(2) = 0.196), and moderate effects with respect HF% (p = 0.099; pη(2) = 0.094), with PLA subjects showing a higher increase in HR and SDNN and a higher decrease in RMSSD, NN50, LF and HF than subjects in the ESC condition. Thus, ESC treatment significantly blunted the autonomic reactivity to CCK-4. Secondary analysis indicated no effect of the 5-HTTLPR polymorphism on CCK-4-induced autonomic response. CONCLUSIONS Our results support findings suggesting an effect of SSRI treatment on autonomic regulation and provide evidence that ESC treatment is associated with blunted autonomic reactivity in healthy men.
Collapse
Affiliation(s)
- Agorastos Agorastos
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Drs Agorastos, Kellner, Muhtz, Wiedemann, and Demiralay); Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Dr Muhtz).
| | - Michael Kellner
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Drs Agorastos, Kellner, Muhtz, Wiedemann, and Demiralay); Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Dr Muhtz)
| | - Oliver Stiedl
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Drs Agorastos, Kellner, Muhtz, Wiedemann, and Demiralay); Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Dr Muhtz)
| | - Christoph Muhtz
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Drs Agorastos, Kellner, Muhtz, Wiedemann, and Demiralay); Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Dr Muhtz)
| | - Klaus Wiedemann
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Drs Agorastos, Kellner, Muhtz, Wiedemann, and Demiralay); Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Dr Muhtz)
| | - Cüneyt Demiralay
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Drs Agorastos, Kellner, Muhtz, Wiedemann, and Demiralay); Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus, VU University, Amsterdam, Netherlands (Dr Stiedl); Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (Dr Muhtz)
| |
Collapse
|
20
|
Albert PR, Benkelfat C. The neurobiology of depression--revisiting the serotonin hypothesis. II. Genetic, epigenetic and clinical studies. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120535. [PMID: 23440469 DOI: 10.1098/rstb.2012.0535] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The serotonin system originates from a small number of neurons (a few hundred thousand of the 100 billion in man) located in the midbrain raphe nuclei, that project widely throughout the central nervous system to influence a large array of inter-related biological functions, not least of which are circuits involved in mood and emotion. The serotonin hypothesis of depression has postulated that a reduction in serotonin leads to increased predisposition to depression. Indeed, it has become evident from therapeutic strategies that affect serotonin activity, that alterations in serotonin may not only predispose to depression, but also to aggressive behaviour, impulsivity, obsessive-compulsive behaviour and suicide. Many potential mechanisms known to alter the genes that regulate the serotonin system, including developmental epigenetic modifications, are presented, as additional evidence implicating the serotonin system. This second issue of two special issues of Philosophical Transactions B presents a series of reviews, perspectives and new findings that argue that the serotonin hypothesis remains an important idea that continues to guide research into the aetiology and treatment of depression.
Collapse
Affiliation(s)
- Paul R Albert
- Ottawa Hospital Research Institute (Neuroscience), University of Ottawa, Ottawa, Ontario, Canada.
| | | |
Collapse
|
21
|
Albert PR, Benkelfat C. The neurobiology of depression--revisiting the serotonin hypothesis. II. Genetic, epigenetic and clinical studies. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120535. [PMID: 23440469 DOI: 10.1098/rstb.2012.0535.pubmed] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2023] Open
Abstract
The serotonin system originates from a small number of neurons (a few hundred thousand of the 100 billion in man) located in the midbrain raphe nuclei, that project widely throughout the central nervous system to influence a large array of inter-related biological functions, not least of which are circuits involved in mood and emotion. The serotonin hypothesis of depression has postulated that a reduction in serotonin leads to increased predisposition to depression. Indeed, it has become evident from therapeutic strategies that affect serotonin activity, that alterations in serotonin may not only predispose to depression, but also to aggressive behaviour, impulsivity, obsessive-compulsive behaviour and suicide. Many potential mechanisms known to alter the genes that regulate the serotonin system, including developmental epigenetic modifications, are presented, as additional evidence implicating the serotonin system. This second issue of two special issues of Philosophical Transactions B presents a series of reviews, perspectives and new findings that argue that the serotonin hypothesis remains an important idea that continues to guide research into the aetiology and treatment of depression.
Collapse
Affiliation(s)
- Paul R Albert
- Ottawa Hospital Research Institute (Neuroscience), University of Ottawa, Ottawa, Ontario, Canada.
| | | |
Collapse
|