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Higa GSV, Viana FJC, Francis-Oliveira J, Cruvinel E, Franchin TS, Marcourakis T, Ulrich H, De Pasquale R. Serotonergic neuromodulation of synaptic plasticity. Neuropharmacology 2024; 257:110036. [PMID: 38876308 DOI: 10.1016/j.neuropharm.2024.110036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/15/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024]
Abstract
Synaptic plasticity constitutes a fundamental process in the reorganization of neural networks that underlie memory, cognition, emotional responses, and behavioral planning. At the core of this phenomenon lie Hebbian mechanisms, wherein frequent synaptic stimulation induces long-term potentiation (LTP), while less activation leads to long-term depression (LTD). The synaptic reorganization of neuronal networks is regulated by serotonin (5-HT), a neuromodulator capable of modify synaptic plasticity to appropriately respond to mental and behavioral states, such as alertness, attention, concentration, motivation, and mood. Lately, understanding the serotonergic Neuromodulation of synaptic plasticity has become imperative for unraveling its impact on cognitive, emotional, and behavioral functions. Through a comparative analysis across three main forebrain structures-the hippocampus, amygdala, and prefrontal cortex, this review discusses the actions of 5-HT on synaptic plasticity, offering insights into its role as a neuromodulator involved in emotional and cognitive functions. By distinguishing between plastic and metaplastic effects, we provide a comprehensive overview about the mechanisms of 5-HT neuromodulation of synaptic plasticity and associated functions across different brain regions.
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Affiliation(s)
- Guilherme Shigueto Vilar Higa
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil; Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Felipe José Costa Viana
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - José Francis-Oliveira
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Emily Cruvinel
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Thainá Soares Franchin
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Tania Marcourakis
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Henning Ulrich
- Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Roberto De Pasquale
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil.
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2
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Yu XD, Zhu Y, Sun QX, Deng F, Wan J, Zheng D, Gong W, Xie SZ, Shen CJ, Fu JY, Huang H, Lai HY, Jin J, Li Y, Li XM. Distinct serotonergic pathways to the amygdala underlie separate behavioral features of anxiety. Nat Neurosci 2022; 25:1651-1663. [PMID: 36446933 DOI: 10.1038/s41593-022-01200-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 10/12/2022] [Indexed: 11/30/2022]
Abstract
Anxiety-like behaviors in mice include social avoidance and avoidance of bright spaces. Whether these features are distinctly regulated is unclear. We demonstrate that in mice, social and anxiogenic stimuli, respectively, increase and decrease serotonin (5-HT) levels in basal amygdala (BA). In dorsal raphe nucleus (DRN), 5-HT∩vGluT3 neurons projecting to BA parvalbumin (DRN5-HT∩vGluT3-BAPV) and pyramidal (DRN5-HT∩vGluT3-BAPyr) neurons have distinct intrinsic properties and gene expression and respond to anxiogenic and social stimuli, respectively. Activation of DRN5-HT∩vGluT3→BAPV inhibits 5-HT release via GABAB receptors on serotonergic terminals in BA, inducing social avoidance and avoidance of bright spaces. Activation of DRN5-HT∩vGluT3→BA neurons inhibits two subsets of BAPyr neurons via 5-HT1A receptors (HTR1A) and 5-HT1B receptors (HTR1B). Pharmacological inhibition of HTR1A and HTR1B in BA induces avoidance of bright spaces and social avoidance, respectively. These findings highlight the functional significance of heterogenic inputs from DRN to BA subpopulations in the regulation of separate anxiety-related behaviors.
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Affiliation(s)
- Xiao-Dan Yu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.,Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Zhu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Qi-Xin Sun
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Fei Deng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Jinxia Wan
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Di Zheng
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Wankun Gong
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shi-Ze Xie
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Chen-Jie Shen
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Jia-Yu Fu
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Huiqian Huang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hsin-Yi Lai
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.,College of Biomedical Engineering and Instrument Science, Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, China.,Affiliated Mental Health Center & Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jin Jin
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Xiao-Ming Li
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China. .,Center for Brain Science and Brain-Inspired Intelligence, Research Units for Emotion and Emotion Disorders, Chinese Academy of Medical Sciences/Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou, China.
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3
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Collins HM, Pinacho R, Ozdemir D, Bannerman DM, Sharp T. Effect of selective serotonin reuptake inhibitor discontinuation on anxiety-like behaviours in mice. J Psychopharmacol 2022; 36:794-805. [PMID: 35607713 PMCID: PMC9247435 DOI: 10.1177/02698811221093032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Abrupt cessation of therapy with a selective serotonin reuptake inhibitor (SSRI) is associated with a discontinuation syndrome, typified by numerous disabling symptoms, including anxiety. Surprisingly, little is known of the behavioural effect of SSRI discontinuation in animals. AIM Here, the effect of SSRI discontinuation on anxiety-like behaviour was systematically investigated in mice. METHODS Experiments were based on a three-arm experimental design comprising saline, continued SSRI and discontinued SSRI. Mice were assessed 2 days after SSRI discontinuation over a 5-day period using the elevated plus maze (EPM) and other anxiety tests. RESULTS An exploratory experiment found cessation of paroxetine (12 days) was associated with decreased open-arm exploration and reduced total distance travelled, in male but not female mice. Follow-up studies confirmed a discontinuation effect on the EPM in male mice after paroxetine (12 days) and also citalopram (12 days). Mice receiving continued paroxetine (but not citalopram) also showed decreased open-arm exploration but this was dissociable from the effects of discontinuation. The discontinuation response to paroxetine did not strengthen after 28 days of treatment but was absent after 7 days of treatment. A discontinuation response was not discernible in other anxiety and fear-learning tests applied 3-5 days after treatment cessation. Finally, discontinuation effects on the EPM were typically associated with decreased locomotion on the test. However, separate locomotor testing implicated anxiety-provoked behavioural inhibition rather than a general reduction in motor activity. CONCLUSION Overall, this study provides evidence for a short-lasting behavioural discontinuation response to cessation of SSRI treatment in mice.
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Affiliation(s)
- Helen M Collins
- Department of Pharmacology,
University of Oxford, Oxford, UK,Department of Experimental
Psychology, University of Oxford, Oxford, UK
| | - Raquel Pinacho
- Department of Pharmacology,
University of Oxford, Oxford, UK,Department of Experimental
Psychology, University of Oxford, Oxford, UK
| | - Dersu Ozdemir
- Department of Pharmacology,
University of Oxford, Oxford, UK
| | - David M Bannerman
- Department of Experimental
Psychology, University of Oxford, Oxford, UK
| | - Trevor Sharp
- Department of Pharmacology,
University of Oxford, Oxford, UK,Trevor Sharp, Department of
Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT,
UK.
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4
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Fonseca R, Madeira N, Simoes C. Resilience to fear: The role of individual factors in amygdala response to stressors. Mol Cell Neurosci 2020; 110:103582. [PMID: 33346000 DOI: 10.1016/j.mcn.2020.103582] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 11/13/2020] [Accepted: 12/02/2020] [Indexed: 10/22/2022] Open
Abstract
Resilience to stress is an adaptive process that varies individually. Resilience refers to the adaptation, or the ability to maintain or regain mental health, despite being subject to adverse situation. Resilience is a dynamic concept that reflects a combination of internal individual factors, including age and gender interacting with external factors such as social, cultural and environmental factors. In the last decade, we have witnessed an increase in the prevalence of anxiety disorders, including post-traumatic stress disorder. Given that stress in unavoidable, it is of great interest to understand the neurophysiological mechanisms of resilience, the individual factors that may contribute to susceptibility and promote efficacious approaches to improve resilience. Here, we address this complex question, attempting at defining clear and operational definitions that may allow us to improve our analysis of behavior incorporating individuality. We examine how individual perception of the stressor can alter the outcome of an adverse situation using as an example, the fear-conditioning paradigm and discuss how individual differences in the reward system can contribute to resilience. Given the central role of the endocannabinoid system in regulating fear responses and anxiety, we discuss the evidence that polymorphisms in several molecules of this signaling system contribute to different anxiety phenotypes. The endocannabinoid system is highly interconnected with the serotoninergic and dopaminergic modulatory systems, contributing to individual differences in stress perception and coping mechanisms. We review how the individual variability in these modulatory systems can be used towards a multivariable assessment of stress risk. Incorporating individuality in our research will allow us to define biomarkers of anxiety disorders as well as assess prognosis, towards a personalized clinical approach to mental health.
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Affiliation(s)
- Rosalina Fonseca
- Cellular and Systems Neurobiology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130 1169-056 Lisboa, Portugal.
| | - Natália Madeira
- Cellular and Systems Neurobiology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130 1169-056 Lisboa, Portugal
| | - Carla Simoes
- Cellular and Systems Neurobiology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130 1169-056 Lisboa, Portugal
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5
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Neuromodulators and Long-Term Synaptic Plasticity in Learning and Memory: A Steered-Glutamatergic Perspective. Brain Sci 2019; 9:brainsci9110300. [PMID: 31683595 PMCID: PMC6896105 DOI: 10.3390/brainsci9110300] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/29/2019] [Indexed: 12/19/2022] Open
Abstract
The molecular pathways underlying the induction and maintenance of long-term synaptic plasticity have been extensively investigated revealing various mechanisms by which neurons control their synaptic strength. The dynamic nature of neuronal connections combined with plasticity-mediated long-lasting structural and functional alterations provide valuable insights into neuronal encoding processes as molecular substrates of not only learning and memory but potentially other sensory, motor and behavioural functions that reflect previous experience. However, one key element receiving little attention in the study of synaptic plasticity is the role of neuromodulators, which are known to orchestrate neuronal activity on brain-wide, network and synaptic scales. We aim to review current evidence on the mechanisms by which certain modulators, namely dopamine, acetylcholine, noradrenaline and serotonin, control synaptic plasticity induction through corresponding metabotropic receptors in a pathway-specific manner. Lastly, we propose that neuromodulators control plasticity outcomes through steering glutamatergic transmission, thereby gating its induction and maintenance.
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6
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Sengupta A, Holmes A. A Discrete Dorsal Raphe to Basal Amygdala 5-HT Circuit Calibrates Aversive Memory. Neuron 2019; 103:489-505.e7. [PMID: 31204082 DOI: 10.1016/j.neuron.2019.05.029] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/14/2019] [Accepted: 05/15/2019] [Indexed: 11/26/2022]
Abstract
Despite a wealth of clinical and preclinical data implicating the serotonin (5-HT) system in fear-related affective disorders, a precise definition of this neuromodulator's role in fear remains elusive. Using convergent anatomical and functional approaches, we interrogate the contribution to fear of basal amygdala (BA) 5-HT inputs from the dorsal raphe nucleus (DRN). We show the DRN→BA 5-HT pathway is engaged during fear memory formation and retrieval, and activity of these projections facilitates fear and impairs extinction. The DRN→BA 5-HT pathway amplifies fear-associated BA neuronal firing and theta power and phase-locking. Although fear recruits 5-HT and VGluT3 co-expressing DRN neurons, the fear-potentiating influence of the DRN→BA 5-HT pathway requires signaling at BA 5-HT1A/2A receptors. Input-output mapping illustrates how the DRN→BA 5-HT pathway is anatomically distinct and connected with other brain regions that mediate fear. These findings reveal how a discrete 5-HT circuit orchestrates a broader neural network to calibrate aversive memory.
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Affiliation(s)
- Ayesha Sengupta
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD, USA.
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD, USA.
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7
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Enhanced discriminative aversive learning and amygdala responsivity in 5-HT transporter mutant mice. Transl Psychiatry 2019; 9:139. [PMID: 30996249 PMCID: PMC6470159 DOI: 10.1038/s41398-019-0476-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 02/07/2019] [Accepted: 02/12/2019] [Indexed: 12/31/2022] Open
Abstract
Genetic variation in the human serotonin transporter (5-HTT) has been linked to altered fear learning but the data are inconsistent and the mechanism is unclear. The present study investigated conditioned aversive learning in 5-HTT knockout (KO) mice while simultaneously recording neural network activity (theta oscillations) and hemodynamic responses (tissue oxygen delivery) from the amygdala, a brain region necessary for forming fearful memories. Conditioned aversive learning was measured using a discrimination learning task in which one auditory cue was paired with foot-shock, whereas a second auditory cue was not. Compared with wild-type mice, 5-HTTKO mice exhibited faster discrimination learning. This effect was associated with stronger theta frequency oscillations and greater hemodynamic changes in the amygdala in response to both the emotionally relevant cues and the unconditioned foot-shock stimulus. Furthermore, hemodynamic responses to the unconditioned stimulus predicted behavioral discrimination performance the following day. Acute pharmacological 5-HTT blockade in wild-type mice produced a similar effect, to the extent that administration of citalopram during the fear conditioning sessions enhanced fear memory recall. Collectively, our data argue that loss of 5-HTT function enhances amygdala responsivity to aversive events and facilitates learning for emotionally relevant cues.
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8
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Phi Van VD, Krause ET, Phi-Van L. Modulation of Fear and Arousal Behavior by Serotonin Transporter (5-HTT) Genotypes in Newly Hatched Chickens. Front Behav Neurosci 2018; 12:284. [PMID: 30524254 PMCID: PMC6256247 DOI: 10.3389/fnbeh.2018.00284] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 11/05/2018] [Indexed: 12/20/2022] Open
Abstract
The serotonin transporter (5-HTT) plays a key role in regulating serotonergic transmission via removal of serotonin (5-hydroxytryptamine, 5-HT) from synaptic clefts. Alterations in 5-HTT expression and 5-HT transmission have been shown to cause changes to adult behavior including fear. The objective of the present study was to investigate the 5-HTT role in fear in birds at the very early stages of post-hatching life. Using an avoidance test with an elevated balance beam, which was based on depth perception and the respective fear of heights, we assessed fear-related avoidance behaviors of newly hatched chicks of the three functional 5-HTT genotypes W/W, W/D and D/D. Newly hatched chicks of the genotype D/D, which was linked to high 5-HTT expression, showed less intensive avoidance responses as measured by decreased latency to jump than W/W and W/D chicks. Further, significantly fewer D/D hens than W/W hens showed fear-like behavior that resembled a freezing response. Furthermore, in an arousal test the arousal reaction of the chicks in response to an acute short-term visual social deprivation in the home compartment was assessed 5 weeks after hatching, which also revealed that D/D chicks exhibited decreased arousal reaction, compared to W/W chicks. Thus, the results indicate that fear responses differ in D/D chicks in the early post-hatching periods, possibly due to the different expression of 5-HTT respectively 5-HT levels in this strain.
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Affiliation(s)
- Valerie D Phi Van
- Institute of Diagnostic and Interventional Radiology, University Hospital Zürich, Zürich, Switzerland
| | - E Tobias Krause
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut (FLI), Celle, Germany
| | - Loc Phi-Van
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut (FLI), Celle, Germany
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9
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Matrov D, Kaart T, Lanfumey L, Maldonado R, Sharp T, Tordera RM, Kelly PA, Deakin B, Harro J. Cerebral oxidative metabolism mapping in four genetic mouse models of anxiety and mood disorders. Behav Brain Res 2018; 356:435-443. [PMID: 29885846 DOI: 10.1016/j.bbr.2018.05.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/29/2018] [Accepted: 05/29/2018] [Indexed: 02/06/2023]
Abstract
The psychopathology of depression is highly complex and the outcome of studies on animal models is divergent. In order to find brain regions that could be metabolically distinctively active across a variety of mouse depression models and to compare the interconnectivity of brain regions of wild-type and such genetically modified mice, histochemical mapping of oxidative metabolism was performed by the measurement of cytochrome oxidase activity. We included mice with the heterozygous knockout of the vesicular glutamate transporter (VGLUT1-/+), full knockout of the cannabinoid 1 receptor (CB1-/-), an anti-sense knockdown of the glucocorticoid receptor (GRi) and overexpression of the human 5-hydroxytryptamine transporter (h5-HTT). Altogether 76 mouse brains were studied to measure oxidative metabolism in one hundred brain regions, and the obtained dataset was submitted to a variety of machine learning algorithms and multidimensional scaling. Overall, the top brain regions having the largest contribution to classification into depression model were the lateroanterior hypothalamic nucleus, the anterior part of the basomedial amygdaloid nucleus, claustrum, the suprachiasmatic nucleus, the ventromedial hypothalamic nucleus, and the anterior hypothalamic area. In terms of the patterns of inter-regional relationship between wild-type and genetically modified mice there was little overall difference, while the most deviating brain regions were cortical amygdala and ventrolateral and ventral posteromedial thalamic nuclei. The GRi mice that most clearly differed from their controls exhibited deviation of connectivity for a number of brain regions, such as ventrolateral thalamic nucleus, the intermediate part of the lateral septal nucleus, the anteriodorsal part of the medial amygdaloid nucleus, the medial division of the central amygdaloid nucleus, ventral pallidum, nucleus of the vertical limb of the diagonal band, anteroventral parts of the thalamic nucleus and parts of the bed nucleus of the stria terminalis. Conclusively, the GRi mouse model was characterized by changes in the functional connectivity of the extended amygdala and stress response circuits.
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Affiliation(s)
- Denis Matrov
- Division of Neuropsychopharmacology, Department of Psychology, University of Tartu, Ravila 14A Chemicum, 50411 Tartu, Estonia; Department of Neuroscience, Graduate School of Medicine, Kyoto University, Yoshida-konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Tanel Kaart
- Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51014 Tartu, Estonia
| | - Laurence Lanfumey
- Centre de Psychiatrie et Neuroscience, INSERM U 894, 2 ter rue d'Alésia, 75014 Paris, France
| | - Rafael Maldonado
- Laboratory of Neuropharmacology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, United Kingdom
| | - Rosa M Tordera
- Department of Pharmacology and Toxicology, University of Navarra, Pamplona, Spain
| | - Paul A Kelly
- Centre for Cognitive and Neural Systems, University of Edinburgh, Scotland, United Kingdom
| | - Bill Deakin
- Neuroscience and Psychiatry Unit, Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, United Kingdom
| | - Jaanus Harro
- Division of Neuropsychopharmacology, Department of Psychology, University of Tartu, Ravila 14A Chemicum, 50411 Tartu, Estonia.
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10
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Neural Oscillatory Correlates for Conditioning and Extinction of Fear. Biomedicines 2018; 6:biomedicines6020049. [PMID: 29724018 PMCID: PMC6027138 DOI: 10.3390/biomedicines6020049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/23/2018] [Accepted: 04/28/2018] [Indexed: 12/27/2022] Open
Abstract
The extinction of conditioned-fear represents a hallmark of current exposure therapies as it has been found to be impaired in people suffering from post-traumatic stress disorder (PTSD) and anxiety. A large body of knowledge focusing on psychophysiological animal and human studies suggests the involvement of key brain structures that interact via neural oscillations during the acquisition and extinction of fear. Consequently, neural oscillatory correlates of such mechanisms appear relevant regarding the development of novel therapeutic approaches to counterbalance abnormal activity in fear-related brain circuits, which, in turn, could alleviate fear and anxiety symptoms. Here, we provide an account of state-of-the-art neural oscillatory correlates for the conditioning and extinction of fear, and also deal with recent translational efforts aimed at fear extinction by neural oscillatory modulation.
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11
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Babaev O, Piletti Chatain C, Krueger-Burg D. Inhibition in the amygdala anxiety circuitry. Exp Mol Med 2018; 50:1-16. [PMID: 29628509 PMCID: PMC5938054 DOI: 10.1038/s12276-018-0063-8] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 01/09/2023] Open
Abstract
Inhibitory neurotransmission plays a key role in anxiety disorders, as evidenced by the anxiolytic effect of the benzodiazepine class of γ-aminobutyric acid (GABA) receptor agonists and the recent discovery of anxiety-associated variants in the molecular components of inhibitory synapses. Accordingly, substantial interest has focused on understanding how inhibitory neurons and synapses contribute to the circuitry underlying adaptive and pathological anxiety behaviors. A key element of the anxiety circuitry is the amygdala, which integrates information from cortical and thalamic sensory inputs to generate fear and anxiety-related behavioral outputs. Information processing within the amygdala is heavily dependent on inhibitory control, although the specific mechanisms by which amygdala GABAergic neurons and synapses regulate anxiety-related behaviors are only beginning to be uncovered. Here, we summarize the current state of knowledge and highlight open questions regarding the role of inhibition in the amygdala anxiety circuitry. We discuss the inhibitory neuron subtypes that contribute to the processing of anxiety information in the basolateral and central amygdala, as well as the molecular determinants, such as GABA receptors and synapse organizer proteins, that shape inhibitory synaptic transmission within the anxiety circuitry. Finally, we conclude with an overview of current and future approaches for converting this knowledge into successful treatment strategies for anxiety disorders.
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Affiliation(s)
- Olga Babaev
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Carolina Piletti Chatain
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany.
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12
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Bogdan R, Salmeron BJ, Carey CE, Agrawal A, Calhoun VD, Garavan H, Hariri AR, Heinz A, Hill MN, Holmes A, Kalin NH, Goldman D. Imaging Genetics and Genomics in Psychiatry: A Critical Review of Progress and Potential. Biol Psychiatry 2017; 82:165-175. [PMID: 28283186 PMCID: PMC5505787 DOI: 10.1016/j.biopsych.2016.12.030] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 12/21/2016] [Accepted: 12/28/2016] [Indexed: 12/17/2022]
Abstract
Imaging genetics and genomics research has begun to provide insight into the molecular and genetic architecture of neural phenotypes and the neural mechanisms through which genetic risk for psychopathology may emerge. As it approaches its third decade, imaging genetics is confronted by many challenges, including the proliferation of studies using small sample sizes and diverse designs, limited replication, problems with harmonization of neural phenotypes for meta-analysis, unclear mechanisms, and evidence that effect sizes may be more modest than originally posited, with increasing evidence of polygenicity. These concerns have encouraged the field to grow in many new directions, including the development of consortia and large-scale data collection projects and the use of novel methods (e.g., polygenic approaches, machine learning) that enhance the quality of imaging genetic studies but also introduce new challenges. We critically review progress in imaging genetics and offer suggestions and highlight potential pitfalls of novel approaches. Ultimately, the strength of imaging genetics and genomics lies in their translational and integrative potential with other research approaches (e.g., nonhuman animal models, psychiatric genetics, pharmacologic challenge) to elucidate brain-based pathways that give rise to the vast individual differences in behavior as well as risk for psychopathology.
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Affiliation(s)
- Ryan Bogdan
- BRAIN Lab, Department of Psychological and Brain Sciences, St. Louis, Missouri.
| | - Betty Jo Salmeron
- Neuroimaging Research Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland
| | - Caitlin E Carey
- BRAIN Lab, Department of Psychological and Brain Sciences, St. Louis, Missouri
| | - Arpana Agrawal
- Department of Psychiatry, Washington University in St. Louis, St. Louis, Missouri
| | - Vince D Calhoun
- Mind Research Network and Lovelace Biomedical and Environmental Research Institute, University of New Mexico, Albuquerque, New Mexico; Departments of Psychiatry and Neuroscience, University of New Mexico, Albuquerque, New Mexico; Electronic and Computer Engineering, University of New Mexico, Albuquerque, New Mexico
| | - Hugh Garavan
- Department of Psychiatry, University of Vermont, Burlington, Vermont
| | - Ahmad R Hariri
- Laboratory of NeuroGenetics, Department of Psychology & Neuroscience, Duke University, Durham, North Carolina
| | - Andreas Heinz
- Department of Child and Adolescent Psychiatry, Psychosomatics, and Psychotherapy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Matthew N Hill
- Hotchkiss Brain Institute, Departments of Cell Biology and Anatomy and Psychiatry, University of Calgary, Calgary, Alberta, Canada
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
| | - Ned H Kalin
- Department of Psychiatry, University of Wisconsin, Madison, Wisconsin; Neuroscience Training Program (NHK, RK, PHR, DPMT, MEE), University of Wisconsin, Madison, Wisconsin; Wisconsin National Primate Research Center (NHK, MEE), Madison, Wisconsin
| | - David Goldman
- Laboratory of Neurogenetics, Intramural Research Program, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland
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Bähner F, Meyer-Lindenberg A. Hippocampal-prefrontal connectivity as a translational phenotype for schizophrenia. Eur Neuropsychopharmacol 2017; 27:93-106. [PMID: 28089652 DOI: 10.1016/j.euroneuro.2016.12.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 11/16/2016] [Accepted: 12/19/2016] [Indexed: 01/05/2023]
Abstract
Finding novel biological targets in psychiatry has been difficult, partly because current diagnostic categories are not defined by pathophysiology and difficult to model in animals. The study of species-conserved systems-level mechanisms implicated in psychiatric disease could be a promising strategy to address some of these difficulties. Altered hippocampal-prefrontal (HC-PFC) connectivity during working memory (WM) processing is a candidate for such a translational phenotype as it has been repeatedly associated with impaired cognition in schizophrenia patients and animal models for psychiatric risk factors. Specifically, persistent hippocampus-dorsolateral prefrontal cortex (HC-DLPFC) coupling during WM is an intermediate phenotype for schizophrenia that has been observed in patients, healthy relatives and carriers of two different risk polymorphisms identified in genome-wide association studies. Rodent studies report reduced coherence between HC and PFC during anesthesia, sleep and task performance in both genetic, environmental and neurodevelopmental models for schizophrenia. We discuss several challenges for translation including differences in anatomy, recording modalities and WM paradigms and suggest that a better understanding of HC-PFC coupling across species can be achieved if translational neuroimaging is used to control for task differences. The evidence for potential neurobiological substrates underlying HC-PFC dysconnectivity is evaluated and research strategies are proposed that aim to bridge the gap between findings from large-scale association studies and disease mechanisms.
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Affiliation(s)
- Florian Bähner
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany; Bernstein Center for Computational Neuroscience Heidelberg-Mannheim, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany.
| | - Andreas Meyer-Lindenberg
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany; Bernstein Center for Computational Neuroscience Heidelberg-Mannheim, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany
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14
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Bocchio M, McHugh SB, Bannerman DM, Sharp T, Capogna M. Serotonin, Amygdala and Fear: Assembling the Puzzle. Front Neural Circuits 2016; 10:24. [PMID: 27092057 PMCID: PMC4820447 DOI: 10.3389/fncir.2016.00024] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/21/2016] [Indexed: 11/13/2022] Open
Abstract
The fear circuitry orchestrates defense mechanisms in response to environmental threats. This circuitry is evolutionarily crucial for survival, but its dysregulation is thought to play a major role in the pathophysiology of psychiatric conditions in humans. The amygdala is a key player in the processing of fear. This brain area is prominently modulated by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). The 5-HT input to the amygdala has drawn particular interest because genetic and pharmacological alterations of the 5-HT transporter (5-HTT) affect amygdala activation in response to emotional stimuli. Nonetheless, the impact of 5-HT on fear processing remains poorly understood.The aim of this review is to elucidate the physiological role of 5-HT in fear learning via its action on the neuronal circuits of the amygdala. Since 5-HT release increases in the basolateral amygdala (BLA) during both fear memory acquisition and expression, we examine whether and how 5-HT neurons encode aversive stimuli and aversive cues. Next, we describe pharmacological and genetic alterations of 5-HT neurotransmission that, in both rodents and humans, lead to altered fear learning. To explore the mechanisms through which 5-HT could modulate conditioned fear, we focus on the rodent BLA. We propose that a circuit-based approach taking into account the localization of specific 5-HT receptors on neurochemically-defined neurons in the BLA may be essential to decipher the role of 5-HT in emotional behavior. In keeping with a 5-HT control of fear learning, we review electrophysiological data suggesting that 5-HT regulates synaptic plasticity, spike synchrony and theta oscillations in the BLA via actions on different subcellular compartments of principal neurons and distinct GABAergic interneuron populations. Finally, we discuss how recently developed optogenetic tools combined with electrophysiological recordings and behavior could progress the knowledge of the mechanisms underlying 5-HT modulation of fear learning via action on amygdala circuits. Such advancement could pave the way for a deeper understanding of 5-HT in emotional behavior in both health and disease.
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Affiliation(s)
- Marco Bocchio
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford Oxford, UK
| | - Stephen B McHugh
- Department of Experimental Psychology, University of Oxford Oxford, UK
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford Oxford, UK
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford Oxford, UK
| | - Marco Capogna
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford Oxford, UK
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Åhs F, Frick A, Furmark T, Fredrikson M. Human serotonin transporter availability predicts fear conditioning. Int J Psychophysiol 2015; 98:515-9. [DOI: 10.1016/j.ijpsycho.2014.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 11/28/2014] [Accepted: 12/03/2014] [Indexed: 11/29/2022]
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Bocchio M, Fucsina G, Oikonomidis L, McHugh SB, Bannerman DM, Sharp T, Capogna M. Increased Serotonin Transporter Expression Reduces Fear and Recruitment of Parvalbumin Interneurons of the Amygdala. Neuropsychopharmacology 2015; 40:3015-26. [PMID: 26052039 PMCID: PMC4864439 DOI: 10.1038/npp.2015.157] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/20/2015] [Accepted: 05/26/2015] [Indexed: 12/31/2022]
Abstract
Genetic association studies suggest that variations in the 5-hydroxytryptamine (5-HT; serotonin) transporter (5-HTT) gene are associated with susceptibility to psychiatric disorders such as anxiety or posttraumatic stress disorder. Individuals carrying high 5-HTT-expressing gene variants display low amygdala reactivity to fearful stimuli. Mice overexpressing the 5-HTT (5-HTTOE), an animal model of this human variation, show impaired fear, together with reduced fear-evoked theta oscillations in the basolateral amygdala (BLA). However, it is unclear how variation in 5-HTT gene expression impacts on the microcircuitry of the BLA to change behavior. We addressed this issue by investigating the activity of parvalbumin (PV)-expressing interneurons (PVINs), the biggest IN population in the basal amygdala (BA). We found that increased 5-HTT expression impairs the recruitment of PVINs (measured by their c-Fos immunoreactivity) during fear. Ex vivo patch-clamp recordings demonstrated that the depolarizing effect of 5-HT on PVINs was mediated by 5-HT2A receptor. In 5-HTTOE mice, 5-HT-evoked depolarization of PVINs and synaptic inhibition of principal cells, which provide the major output of the BA, were impaired. This deficit was because of reduced 5-HT2A function and not because of increased 5-HT uptake. Collectively, these findings provide novel cellular mechanisms that are likely to contribute to differences in emotional behaviors linked with genetic variations of the 5-HTT.
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Affiliation(s)
- Marco Bocchio
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford, UK
| | - Giulia Fucsina
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lydia Oikonomidis
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford, UK,Department of Pharmacology, University of Oxford, Oxford, UK,Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Stephen B McHugh
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Marco Capogna
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Oxford, UK,MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3TH, UK, Tel: +44 1865 271897, Fax: +44 1865 271647, E-mail:
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17
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Structural bases for neurophysiological investigations of amygdaloid complex of the brain. Sci Rep 2015; 5:17052. [PMID: 26608527 PMCID: PMC4660295 DOI: 10.1038/srep17052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/23/2015] [Indexed: 11/08/2022] Open
Abstract
Amygdala (Am) as a part of limbic system of the brain defines such important functions as adaptive behavior of animals, formation of emotions and memory, regulation of endocrine and visceral functions. We worked out, with the help of mathematic modelling of the pattern recognition theory, principles for organization of neurophysiological and neuromorphological studies of Am nuclei, which take into account the existing heterogeneity of its formations and optimize, to a great extent, the protocol for carrying out of such investigations. The given scheme of studies of Am's structural-functional organization at its highly-informative sections can be used as a guide for precise placement of electrodes', cannulae's and microsensors into particular Am nucleus in the brain with the registration not only the nucleus itself, but also its extensions. This information is also important for defining the number of slices covering specific Am nuclei which must be investigated to reveal the physiological role of a particular part of amygdaloid complex.
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18
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McHugh SB, Barkus C, Lima J, Glover LR, Sharp T, Bannerman DM. SERT and uncertainty: serotonin transporter expression influences information processing biases for ambiguous aversive cues in mice. GENES BRAIN AND BEHAVIOR 2015; 14:330-6. [PMID: 25824641 PMCID: PMC4440341 DOI: 10.1111/gbb.12215] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 03/26/2015] [Accepted: 03/26/2015] [Indexed: 12/18/2022]
Abstract
The long allele variant of the serotonin transporter (SERT, 5-HTT) gene-linked polymorphic region (5-HTTLPR) is associated with higher levels of 5-HTT expression and reduced risk of developing affective disorders. However, little is known about the mechanisms underlying this protective effect. One hypothesis is that 5-HTT expression influences aversive information processing, with reduced negative cognitive bias present in those with higher 5-HTT expression. Here we investigated this hypothesis using genetically-modified mice and a novel aversive learning paradigm. Mice with high levels of 5-HTT expression (5-HTT over-expressing, 5-HTTOE mice) and wild-type mice were trained to discriminate between three distinct auditory cues: one cue predicted footshock on all trials (CS+); a second cue predicted the absence of footshock (CS−); and a third cue predicted footshock on 20% of trials (CS20%), and was therefore ambiguous. Wild-type mice exhibited equivalently high levels of fear to the CS+ and CS20% and minimal fear to the CS−. In contrast, 5-HTTOE mice exhibited high levels of fear to the CS+ but minimal fear to the CS− and the CS20%. This selective reduction in fear to ambiguous aversive cues suggests that increased 5-HTT expression reduces negative cognitive bias for stimuli with uncertain outcomes.
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Affiliation(s)
- S B McHugh
- Department of Experimental Psychology, University of Oxford, Oxford, UK
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Jaiswal P, Guhathakurta S, Singh AS, Verma D, Pandey M, Varghese M, Sinha S, Ghosh S, Mohanakumar KP, Rajamma U. SLC6A4 markers modulate platelet 5-HT level and specific behaviors of autism: a study from an Indian population. Prog Neuropsychopharmacol Biol Psychiatry 2015; 56:196-206. [PMID: 25261775 DOI: 10.1016/j.pnpbp.2014.09.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 09/17/2014] [Accepted: 09/17/2014] [Indexed: 10/24/2022]
Abstract
Presence of platelet hyperserotonemia and effective amelioration of behavioral dysfunctions by selective serotonin reuptake inhibitors (SSRI) in autism spectrum disorders (ASD) indicate that irregularities in serotonin (5-HT) reuptake and its homeostasis could be the basis of behavioral impairments in ASD patients. SLC6A4, the gene encoding serotonin transporter (SERT) is considered as a potential susceptibility gene for ASD, since it is a quantitative trait locus for blood 5-HT levels. Three functional polymorphisms, 5-HTTLPR, STin2 and 3'UTR-SNP of SLC6A4 are extensively studied for possible association with the disorder, with inconclusive outcome. In the present study, we investigated association of these polymorphisms with platelet 5-HT content and symptoms severity as revealed by childhood autism rating scale in ASD children from an Indian population. Higher 5-HT level observed in ASD was highly significant in children with heterozygous and homozygous genotypes comprising of minor alleles of the markers. Quantitative transmission disequilibrium test demonstrated significant genetic effect of STin2 allele as well as STin2/3'UTR-SNP and 5-HTTLPR/3'UTR-SNP haplotypes on 5-HT levels, but no direct association with overall CARS score and ASD phenotype. Significant genetic effect of the markers on specific behavioral phenotypes was observed for various sub-phenotypes of CARS in quantitative trait analysis. Even though the 5-HT level was not associated with severity of behavioral CARS score, a significant negative relationship was observed for 5-HT levels and level and consistency of intellectual response and general impression in ASD children. Population-based study revealed higher distribution of the haplotype 10/G of STin2/3'UTR-SNP in male controls, suggesting protective effect of this haplotype in male cases. Overall results of the study suggest that SLC6A4 markers have specific genetic effect on individual ASD behavioral attributes, might be through the modulation of 5-HT content.
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Affiliation(s)
- Preeti Jaiswal
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, India
| | - Subhrangshu Guhathakurta
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, India
| | - Asem Surindro Singh
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, India
| | - Deepak Verma
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, India
| | - Mritunjay Pandey
- Lab of Clinical & Experimental Neurosciences, Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S C Mullick Road, Jadavpur, Kolkata, India
| | - Merina Varghese
- Lab of Clinical & Experimental Neurosciences, Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S C Mullick Road, Jadavpur, Kolkata, India
| | - Swagata Sinha
- Out-Patients Department, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, India
| | - Saurabh Ghosh
- Human Genetics Unit, Indian Statistical Institute, 203 BT Road, Kolkata, India
| | - Kochupurackal P Mohanakumar
- Lab of Clinical & Experimental Neurosciences, Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S C Mullick Road, Jadavpur, Kolkata, India
| | - Usha Rajamma
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, India.
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Line SJ, Barkus C, Rawlings N, Jennings K, McHugh S, Sharp T, Bannerman DM. Reduced sensitivity to both positive and negative reinforcement in mice over-expressing the 5-hydroxytryptamine transporter. Eur J Neurosci 2014; 40:3735-45. [PMID: 25283165 PMCID: PMC4737229 DOI: 10.1111/ejn.12744] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 08/30/2014] [Accepted: 09/02/2014] [Indexed: 11/30/2022]
Abstract
The 5‐hydroxytryptamine (5‐HT) transporter (5‐HTT) is believed to play a key role in both normal and pathological psychological states. Much previous data suggest that the s allele of the polymorphic regulatory region of the 5‐HTT gene promoter is associated with reduced 5‐HTT expression and vulnerability to psychiatric disorders, including anxiety and depression. In comparison, the l allele, which increases 5‐HTT expression, is generally considered protective. However, recent data link this allele to both abnormal 5‐HT signalling and psychopathic traits. Here, we studied the processing of aversive and rewarding cues in transgenic mice that over‐express the 5‐HTT (5‐HTTOE mice). Compared with wild‐type mice, 5‐HTTOE mice froze less in response to both a tone that had previously been paired with footshock, and the conditioning context. In addition, on a decision‐making T‐maze task, 5‐HTTOE mice displayed reduced preference for a larger, delayed reward and increased preference for a smaller, immediate reward, suggesting increased impulsiveness compared with wild‐type mice. However, further inspection of the data revealed that 5‐HTTOE mice displayed a relative insensitivity to reward magnitude, irrespective of delay. In contrast, 5‐HTTOE mice appeared normal on tests of spatial working and reference memory, which required an absolute choice between options associated with either reward or no reward. Overall, the present findings suggest that 5‐HTT over‐expression results in a reduced sensitivity to both positive and negative reinforcers. Thus, these data show that increased 5‐HTT expression has some maladaptive effects, supporting recent suggestions that l allele homozygosity may be a potential risk factor for disabling psychiatric traits.
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Affiliation(s)
- Samantha J Line
- Department of Experimental Psychology, The University of Oxford, South Parks Road, Oxford, OX1 3UD, UK
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Abstract
Prediction error signals are fundamental to learning. Here, in mice, we show that aversive prediction signals are found in the hemodynamic responses and theta oscillations recorded from the basolateral amygdala. During fear conditioning, amygdala responses evoked by footshock progressively decreased, whereas responses evoked by the auditory cue that predicted footshock concomitantly increased. Unexpected footshock evoked larger amygdala responses than expected footshock. The magnitude of the amygdala response to the footshock predicted behavioral responses the following day. The omission of expected footshock led to a decrease below baseline in the amygdala response suggesting a negative aversive prediction error signal. Thus, in mice, amygdala activity conforms to temporal difference models of aversive learning.
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Gryglewski G, Lanzenberger R, Kranz GS, Cumming P. Meta-analysis of molecular imaging of serotonin transporters in major depression. J Cereb Blood Flow Metab 2014; 34:1096-103. [PMID: 24802331 PMCID: PMC4083395 DOI: 10.1038/jcbfm.2014.82] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/04/2014] [Accepted: 04/09/2014] [Indexed: 11/16/2022]
Abstract
The success of serotonin-selective reuptake inhibitors has lent support to the monoamine theory of major depressive disorder (MDD). This issue has been addressed in a number of molecular imaging studies by positron emission tomography or single-photon emission computed tomography of serotonin reuptake sites (5-HTT) in the brain of patients with MDD, with strikingly disparate conclusions. Our meta-analysis of the 18 such studies, totaling 364 MDD patients free from significant comorbidities or medication and 372 control subjects, revealed reductions in midbrain 5-HTT (Hedges' g=-0.49; 95% CI: (-0.84, -0.14)) and amygdala (Hedges' g=-0.50; 95% CI: (-0.78, -0.22)), which no individual study possessed sufficient power to detect. Only small effect sizes were found in other regions with high binding (thalamus: g=-0.24, striatum: g=-0.32, and brainstem g=-0.22), and no difference in the frontal or cingulate cortex. Age emerged as an important moderator of 5-HTT availability in MDD, with more severe reductions in striatal 5-HTT evident with greater age of the study populations (P<0.01). There was a strong relationship between severity of depression and 5-HTT reductions in the amygdala (P=0.01). Thus, molecular imaging findings indeed reveal widespread reductions of ∼10% in 5-HTT availability in MDD, which may predict altered spatial-temporal dynamics of serotonergic neurotransmission.
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Affiliation(s)
- Gregor Gryglewski
- Functional, Molecular & Translational Neuroimaging Lab, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Rupert Lanzenberger
- Functional, Molecular & Translational Neuroimaging Lab, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Georg S Kranz
- Functional, Molecular & Translational Neuroimaging Lab, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Paul Cumming
- Department of Nuclear Medicine, Friederich-Alexanders Universitaet, Erlangen/Nurenberg, Germany
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