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Kukucka T, Ferencova N, Visnovcova Z, Ondrejka I, Hrtanek I, Kovacova V, Macejova A, Mlyncekova Z, Tonhajzerova I. Mechanisms Involved in the Link between Depression, Antidepressant Treatment, and Associated Weight Change. Int J Mol Sci 2024; 25:4511. [PMID: 38674096 PMCID: PMC11050075 DOI: 10.3390/ijms25084511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024] Open
Abstract
Major depressive disorder is a severe mood disorder associated with a marked decrease in quality of life and social functioning, accompanied by a risk of suicidal behavior. Therefore, seeking out and adhering to effective treatment is of great personal and society-wide importance. Weight changes associated with antidepressant therapy are often cited as the reason for treatment withdrawal and thus are an important topic of interest. There indeed exists a significant mechanistic overlap between depression, antidepressant treatment, and the regulation of appetite and body weight. The suggested pathomechanisms include the abnormal functioning of the homeostatic (mostly humoral) and hedonic (mostly dopaminergic) circuits of appetite regulation, as well as causing neuromorphological and neurophysiological changes underlying the development of depressive disorder. However, this issue is still extensively discussed. This review aims to summarize mechanisms linked to depression and antidepressant therapy in the context of weight change.
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Affiliation(s)
- Tomas Kukucka
- Clinic of Psychiatry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital Martin, 03659 Martin, Slovakia; (T.K.); (I.O.); (I.H.); (V.K.); (A.M.); (Z.M.)
| | - Nikola Ferencova
- Biomedical Centre Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, 03601 Martin, Slovakia; (N.F.); (Z.V.)
| | - Zuzana Visnovcova
- Biomedical Centre Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, 03601 Martin, Slovakia; (N.F.); (Z.V.)
| | - Igor Ondrejka
- Clinic of Psychiatry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital Martin, 03659 Martin, Slovakia; (T.K.); (I.O.); (I.H.); (V.K.); (A.M.); (Z.M.)
| | - Igor Hrtanek
- Clinic of Psychiatry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital Martin, 03659 Martin, Slovakia; (T.K.); (I.O.); (I.H.); (V.K.); (A.M.); (Z.M.)
| | - Veronika Kovacova
- Clinic of Psychiatry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital Martin, 03659 Martin, Slovakia; (T.K.); (I.O.); (I.H.); (V.K.); (A.M.); (Z.M.)
| | - Andrea Macejova
- Clinic of Psychiatry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital Martin, 03659 Martin, Slovakia; (T.K.); (I.O.); (I.H.); (V.K.); (A.M.); (Z.M.)
| | - Zuzana Mlyncekova
- Clinic of Psychiatry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital Martin, 03659 Martin, Slovakia; (T.K.); (I.O.); (I.H.); (V.K.); (A.M.); (Z.M.)
| | - Ingrid Tonhajzerova
- Department of Physiology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, 03601 Martin, Slovakia
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Fletcher PJ, Rahbarnia A, Li Z, Ji X, Higgins GA, Funk D, Lê AD. Effects of 5-HT 2C receptor stimulation in male mice on behaviour and Fos expression: feeding, reward and impulsivity. Behav Brain Res 2023; 447:114438. [PMID: 37059187 DOI: 10.1016/j.bbr.2023.114438] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/31/2023] [Accepted: 04/12/2023] [Indexed: 04/16/2023]
Abstract
Serotonin modulates many motivated behaviours via multiple receptor subtypes. Agonists at 5-HT2C receptors have potential for treating behavioural problems associated with obesity and drug use. In this work we examined the impact of the 5-HT2C receptor agonist lorcaserin on several motivated behaviours related to feeding, reward and waiting impulsivity, and on neuronal activation in key brain areas mediating those behaviours. In male C57BL/6J mice effects of lorcaserin (0.2, 1 and 5mg/kg) were examined on feeding, and on operant responding for a palatable reward. Feeding was reduced only at 5mg/kg, whereas operant responding was reduced at 1mg/kg. At a much lower dose range lorcaserin 0.05-0.2mg/kg also reduced impulsive behaviour measured as premature responding in the 5-choice serial reaction time (5-CSRT) test, without affecting attention or ability to perform the task. Lorcaserin induced Fos expression in brain regions related to feeding (paraventricular nucleus and arcuate nucleus), reward (ventral tegmental area), and impulsivity (medial prefrontal cortex, VTA) although these effects did not show the same differential sensitivity to lorcaserin as the behavioural measures. These results indicate a broad profile of action of 5-HT2C receptor stimulation on brain circuitry and on motivated behaviours, but with clear evidence of differential sensitivity across behavioural domains. This is exemplified by that fact that impulsive behaviour was reduced at a much lower dose range than was feeding behaviour. Along with previous work, and some clinical observations, this work supports the idea that 5-HT2C agonists may be useful for behavioural problems associated with impulsivity.
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Affiliation(s)
- Paul J Fletcher
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Department of Psychology, University of Toronto, Toronto, Ontario, Canada.
| | - Arya Rahbarnia
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Zhaoxia Li
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Xiaodong Ji
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Guy A Higgins
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; InterVivo Solutions Inc, Fergus, Ontario, Canada
| | - Douglas Funk
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - A D Lê
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
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The Combination of Galanin (1–15) and Escitalopram in Rats Suggests a New Strategy for Alcohol Use Disorder Comorbidity with Depression. Biomedicines 2022; 10:biomedicines10020412. [PMID: 35203621 PMCID: PMC8962322 DOI: 10.3390/biomedicines10020412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 12/07/2022] Open
Abstract
Alcohol use disorder (AUD) is highly prevalent, and over 50% of AUD patients also suffer major depressive disorders. Selective 5-HT reuptake inhibitors (SSRIs) can reduce rodent ethanol drinking but exert modest clinical efficacy in alcoholic individuals. Finding new pharmacological strategies that could modulate alcohol consumption and depression is necessary. We have analyzed the effect of Galanin (1–15) [GAL(1–15)] on escitalopram (ESC)-mediated effect in alcohol consumption using the alcohol self-administration test, the nuclei involved in the effect, and whether GAL(1–15) + ESC modulated the response in despair or anxiety tests in animals under chronic alcohol intake. GAL(1–15) + ESC combination substantially reduced alcohol intake in the alcohol self-administration test and, moreover, enhanced the reduction of reward capacity of ESC on different reinforcers such as sucrose or saccharine. GAL(1–15) + ESC coadministration significantly decreases the number of C-Fos-IR TH cell bodies in the VTA, and PCA analysis suggests that one functional network, including VTA, RMTg and DR, is involved in these effects. Significantly in rats with chronic alcohol consumption, GAL(1–15) reversed adverse ESC-mediated effects in the depression-related behavioural test and forced swimming test. The results open up the possibility of using GAL(1–15) in combination with the SSRI Escitalopram as a novel strategy in AUD comorbidity with depression.
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Härmson O, Grima LL, Panayi MC, Husain M, Walton ME. 5-HT 2C receptor perturbation has bidirectional influence over instrumental vigour and restraint. Psychopharmacology (Berl) 2022; 239:123-140. [PMID: 34762147 PMCID: PMC8770415 DOI: 10.1007/s00213-021-05992-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/20/2021] [Indexed: 10/25/2022]
Abstract
The serotonin (5-HT) system, particularly the 5-HT2C receptor, has consistently been implicated in behavioural control. However, while some studies have focused on the role 5-HT2C receptors play in regulating motivation to work for reward, others have highlighted its importance in response restraint. To date, it is unclear how 5-HT transmission at this receptor regulates the balance of response invigoration and restraint in anticipation of future reward. In addition, it remains to be established how 5-HT2C receptors gate the influence of internal versus cue-driven processes over reward-guided actions. To elucidate these issues, we investigated the effects of administering the 5-HT2C receptor antagonist SB242084, both systemically and directly into the nucleus accumbens core (NAcC), in rats performing a Go/No-Go task for small or large rewards. The results were compared to the administration of d-amphetamine into the NAcC, which has previously been shown to promote behavioural activation. Systemic perturbation of 5-HT2C receptors-but crucially not intra-NAcC infusions-consistently boosted rats' performance and instrumental vigour on Go trials when they were required to act. Concomitantly, systemic administration also reduced their ability to withhold responding for rewards on No-Go trials, particularly late in the holding period. Notably, these effects were often apparent only when the reward on offer was small. By contrast, inducing a hyperdopaminergic state in the NAcC with d-amphetamine strongly impaired response restraint on No-Go trials both early and late in the holding period, as well as speeding action initiation. Together, these findings suggest that 5-HT2C receptor transmission, outside the NAcC, shapes the vigour of ongoing goal-directed action as well as the likelihood of responding as a function of expected reward.
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Affiliation(s)
- Oliver Härmson
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3SR, UK.
| | - Laura L Grima
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3SR, UK.
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.
| | - Marios C Panayi
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3SR, UK
- National Institute On Drug Abuse, Biomedical Research Center, 251 Bayview Boulevard, Suite 200, Baltimore, MD, 21224, USA
| | - Masud Husain
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3SR, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 9DU, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, OX1 3SR, UK
| | - Mark E Walton
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3SR, UK.
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, OX1 3SR, UK.
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Maiolati M, Tarmati V, Latagliata C, Cabib S, Orsini C. Opposite genotype-specific effects of serotoninergic treatments on Pavlovian Conditioned Approach in mice of two inbred strains C57 BL/6J and DBA/2J. Behav Pharmacol 2021; 32:392-403. [PMID: 33709985 DOI: 10.1097/fbp.0000000000000629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Individual variability in the response to pharmacological therapies is a major problem in the treatment of psychiatric disorders. Comparative studies of phenotypes expressed by mice of the C57BL/6J (C57) and DBA/2J (DBA) inbred strains can help identify neurobiological determinants of this variability at preclinical levels. We have recently demonstrated that whereas young adult mice of both strains develop sign-tracking in a Pavlovian Conditioned Approach (PCA), a trait associated with dysfunctional behavior in rat models, in full adult C57 mice acquisition of this phenotype is inhibited by pre-frontal cortical (PFC) serotonin (5HT) transmission. These findings suggest a different role of 5HT transmission on sign-tracking development in mice of the two genotypes. In the present experiments, we tested the effects of the 5-HT synthesis booster 5-hydroxytryptophan (5-HTP) and of the selective 5HT reuptake inhibitor (SSRI) fluoxetine on the development and expression of sign-tracking in young adult mice from both inbred strains. In mice of the C57 strain, administration of 5-HTP before each training session blocked the training-induced shift to positive PCA scores which indicates the development of sign-tracking, whereas the same treatment was ineffective in mice of DBA strain. On the other hand, a single administration of fluoxetine was ineffective in unhandled saline- and 5-HTP-treated C57 mice, whereas it enhanced the expression of positive PCA scores by mice of DBA strain treated with 5-HTP during training. These findings confirm the strain-specific inhibitory role of PFC 5-HT transmission on sign-tracking development by mice of the C57 strain and support the hypothesis that different genotype-specific neurobiological substrates of dysfunctional phenotypes contribute to variable effects of pharmacotherapies.
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Affiliation(s)
- Marzia Maiolati
- PhD Program in Behavioral Neuroscience, Department of Psychology, University of Rome "Sapienza"
| | - Valeria Tarmati
- PhD Program in Behavioral Neuroscience, Department of Psychology, University of Rome "Sapienza"
| | | | - Simona Cabib
- IRCSS Fondazione Santa Lucia, Department of Experimental Neurosciences
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
| | - Cristina Orsini
- IRCSS Fondazione Santa Lucia, Department of Experimental Neurosciences
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
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Lewis CA, Mueller K, Zsido RG, Reinelt J, Regenthal R, Okon-Singer H, Forbes EE, Villringer A, Sacher J. A single dose of escitalopram blunts the neural response in the thalamus and caudate during monetary loss. J Psychiatry Neurosci 2021; 46:E319-E327. [PMID: 33904667 PMCID: PMC8327975 DOI: 10.1503/jpn.200121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Selective serotonin reuptake inhibitors (SSRIs) show acute effects on the neural processes associated with negative affective bias in healthy people and people with depression. However, whether and how SSRIs also affect reward and punishment processing on a similarly rapid time scale remains unclear. METHODS We investigated the effects of an acute and clinically relevant dose (20 mg) of the SSRI escitalopram on brain response during reward and punishment processing in 19 healthy participants. In a doubleblind, placebo-controlled study using functional MRI, participants performed a well-established monetary reward task at 3 time points: at baseline; after receiving placebo or escitalopram; and after receiving placebo or escitalopram following an 8-week washout period. RESULTS Acute escitalopram administration reduced blood-oxygen-level-dependent (BOLD) response during punishment feedback in the right thalamus (family-wise error corrected [FWE] p = 0.013 at peak level) and the right caudate head (pFWE = 0.011 at peak level) compared to placebo. We did not detect any significant BOLD changes during reward feedback. LIMITATIONS We included only healthy participants, so interpretation of findings are limited to the healthy human brain and require future testing in patient populations. The paradigm we used was based on monetary stimuli, and results may not be generalizable to other forms of reward. CONCLUSION Our findings extend theories of rapid SSRI action on the neural processing of rewarding and aversive stimuli and suggest a specific and acute effect of escitalopram in the punishment neurocircuitry.
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Affiliation(s)
- Carolin A Lewis
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Karsten Mueller
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Rachel G Zsido
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Janis Reinelt
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Ralf Regenthal
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Hadas Okon-Singer
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Erika E Forbes
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Arno Villringer
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
| | - Julia Sacher
- From the Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Lewis, Zsido, Sacher); the International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany (Lewis, Zsido); the Department of Psychiatry and Psychotherapy, Medical School, University of Tuebingen, Germany (Lewis); the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany (Mueller, Reinelt, Villringer); the Max Planck School of Cognition, Leipzig, Germany (Zsido); the Division of Clinical Pharmacology, Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany (Regenthal); the Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa, Israel (Okon-Singer); the Integrated Brain and Behavior Research Center (IBBR), University of Haifa, Haifa, Israel (Okon-Singer); the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA (Forbes); and the Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany (Villringer, Sacher)
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McDevitt RA, Marino RAM, Tejeda HA, Bonci A. Serotonergic inhibition of responding for conditioned but not primary reinforcers. Pharmacol Biochem Behav 2021; 205:173186. [PMID: 33836219 DOI: 10.1016/j.pbb.2021.173186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 02/19/2021] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
Serotonin is widely implicated as a modulator of brain reward function. However, laboratory studies have not yielded a consensus on which specific reward-related processes are influenced by serotonin and in what manner. Here we explored the role of serotonin in cue-reward learning in mice. In a first series of experiments, we found that acute administration of the serotonin reuptake inhibitors citalopram, fluoxetine, or duloxetine all reduced lever pressing reinforced on an FR1 schedule with presentation of a cue that had been previously paired with delivery of food. However, citalopram had no effect on responding that was reinforced with both cue and food on an FR1 schedule. Furthermore, citalopram did not affect nose poke responses that produced no auditory, visual, or proprioceptive cues but were reinforced with food pellets on a progressive ratio schedule. We next performed region-specific knock out of tryptophan hydroxylase-2 (Tph2), the rate-limiting enzyme in serotonin synthesis. Viral delivery of Cre recombinase was targeted to dorsal or median raphe nuclei (DRN, MRN), the major sources of ascending serotonergic projections. MRN but not DRN knockouts were impaired in development of cue-elicited approach during Pavlovian conditioning; both groups were subsequently hyper-responsive when lever pressing for cue presentation. The inhibitory effect of citalopram was attenuated in DRN but not MRN knockouts. Our findings are in agreement with prior studies showing serotonin to suppress responding for conditioned reinforcers. Furthermore, these results suggest an inhibitory role of MRN serotonin neurons in the initial attribution of motivational properties to a reward-predictive cue, but not in its subsequent maintenance. In contrast, the DRN appears to promote the reduction of motivational value attached to a cue when it is presented repeatedly in the absence of primary reward.
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Affiliation(s)
- Ross A McDevitt
- Synaptic Plasticity Section, National Institute on Drug Abuse, Baltimore, MD, United States of America; Comparative Medicine Section, National Institute on Aging, Baltimore, MD, United States of America.
| | - Rosa Anna M Marino
- Synaptic Plasticity Section, National Institute on Drug Abuse, Baltimore, MD, United States of America; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Hugo A Tejeda
- Synaptic Plasticity Section, National Institute on Drug Abuse, Baltimore, MD, United States of America; Neuromodulation and Synaptic Integration Unit, National Institute on Mental Health, Bethesda, MD, United States of America
| | - Antonello Bonci
- Global Institutes on Addictions, Miami, FL, United States of America
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Psychological mechanisms and functions of 5-HT and SSRIs in potential therapeutic change: Lessons from the serotonergic modulation of action selection, learning, affect, and social cognition. Neurosci Biobehav Rev 2020; 119:138-167. [PMID: 32931805 DOI: 10.1016/j.neubiorev.2020.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 12/14/2022]
Abstract
Uncertainty regarding which psychological mechanisms are fundamental in mediating SSRI treatment outcomes and wide-ranging variability in their efficacy has raised more questions than it has solved. Since subjective mood states are an abstract scientific construct, only available through self-report in humans, and likely involving input from multiple top-down and bottom-up signals, it has been difficult to model at what level SSRIs interact with this process. Converging translational evidence indicates a role for serotonin in modulating context-dependent parameters of action selection, affect, and social cognition; and concurrently supporting learning mechanisms, which promote adaptability and behavioural flexibility. We examine the theoretical basis, ecological validity, and interaction of these constructs and how they may or may not exert a clinical benefit. Specifically, we bridge crucial gaps between disparate lines of research, particularly findings from animal models and human clinical trials, which often seem to present irreconcilable differences. In determining how SSRIs exert their effects, our approach examines the endogenous functions of 5-HT neurons, how 5-HT manipulations affect behaviour in different contexts, and how their therapeutic effects may be exerted in humans - which may illuminate issues of translational models, hierarchical mechanisms, idiographic variables, and social cognition.
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5-HT2C receptor blockade reverses SSRI-associated basal ganglia dysfunction and potentiates therapeutic efficacy. Mol Psychiatry 2020; 25:3304-3321. [PMID: 30120415 PMCID: PMC6378140 DOI: 10.1038/s41380-018-0227-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 07/13/2018] [Accepted: 07/24/2018] [Indexed: 11/09/2022]
Abstract
Serotonin (5-HT) selective reuptake inhibitors (SSRIs) are widely used in the treatment of depression and anxiety disorders, but responsiveness is uncertain and side effects often lead to discontinuation. Side effect profiles suggest that SSRIs reduce dopaminergic (DAergic) activity, but specific mechanistic insight is missing. Here we show in mice that SSRIs impair motor function by acting on 5-HT2C receptors in the substantia nigra pars reticulata (SNr), which in turn inhibits nigra pars compacta (SNc) DAergic neurons. SSRI-induced motor deficits can be reversed by systemic or SNr-localized 5-HT2C receptor antagonism. SSRIs induce SNr hyperactivity and SNc hypoactivity that can also be reversed by systemic 5-HT2C receptor antagonism. Optogenetic inhibition of SNc DAergic neurons mimics the motor deficits due to chronic SSRI treatment, whereas local SNr 5-HT2C receptor antagonism or optogenetic activation of SNc DAergic neurons reverse SSRI-induced motor deficits. Lastly, we find that 5-HT2C receptor antagonism potentiates the antidepressant and anxiolytic effects of SSRIs. Together our findings demonstrate opposing roles for 5-HT2C receptors in the effects of SSRIs on motor function and affective behavior, highlighting the potential benefits of 5-HT2C receptor antagonists for both reduction of motor side effects of SSRIs and augmentation of therapeutic antidepressant and anxiolytic effects.
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Dorsal raphe serotonin neurons inhibit operant responding for reward via inputs to the ventral tegmental area but not the nucleus accumbens: evidence from studies combining optogenetic stimulation and serotonin reuptake inhibition. Neuropsychopharmacology 2019; 44:793-804. [PMID: 30420603 PMCID: PMC6372654 DOI: 10.1038/s41386-018-0271-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 10/25/2018] [Accepted: 11/02/2018] [Indexed: 01/16/2023]
Abstract
The monoamine neurotransmitter serotonin (5-hydroxytryptamine; 5-HT) exerts an inhibitory influence over motivation, but the circuits mediating this are unknown. Here, we used an optogenetic approach to isolate the contribution of dorsal raphe nucleus (DRN) 5-HT neurons and 5-HT innervation of the mesolimbic dopamine (DA) system to motivated behavior in mice. We found that optogenetic stimulation of DRN 5-HT neurons enhanced downstream 5-HT release, but this was not sufficient to inhibit operant responding for saccharin, a measure of motivated behavior. However, combining optogenetic stimulation of DRN 5-HT neurons with a low dose of the selective serotonin reuptake inhibitor (SSRI) citalopram synergistically reduced operant responding. We then examined whether these effects could be recapitulated if optogenetic stimulation specifically targeted 5-HT terminals in the ventral tegmental area (VTA) or nucleus accumbens (NAc) of the mesolimbic DA system. Optogenetic stimulation of 5-HT input to the VTA combined with citalopram treatment produced a synergistic decrease in responding for saccharin, resembling the changes produced by targeting 5-HT neurons in the DRN. However, this effect was not observed when optogenetic stimulation targeted 5-HT terminals in the NAc. Taken together, these results suggest that DRN 5-HT neurons exert an inhibitory influence over operant responding for reward through a direct interaction with the mesolimbic DA system at the level of the VTA. These studies support an oppositional interaction between 5-HT and DA systems in controlling motivation and goal-directed behavior, and have important implications for the development and refinement of treatment strategies for psychiatric disorders such as depression and addiction.
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Glucagon-Like Peptide-1 (GLP-1) and 5-Hydroxytryptamine 2c (5-HT 2c) Receptor Agonists in the Ventral Tegmental Area (VTA) Inhibit Ghrelin-Stimulated Appetitive Reward. Int J Mol Sci 2019; 20:ijms20040889. [PMID: 30791361 PMCID: PMC6412472 DOI: 10.3390/ijms20040889] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/12/2019] [Accepted: 02/13/2019] [Indexed: 02/07/2023] Open
Abstract
Current literature indicates that the orexigenic peptide ghrelin increases appetitive motivation via signaling in the mesolimbic reward system. Another gastric peptide, glucagon-like peptide-1 (GLP-1), and the neurotransmitter 5-hydroxytryptamine (5-HT), are both known to suppress operant responding for food by acting on key mesolimbic nuclei, including the ventral tegmental area (VTA). In order to investigate the interaction effects of ghrelin, GLP-1, and 5-HT within the VTA, we measured operant responding for sucrose pellets after the administration of ghrelin, the GLP-1 receptor agonist exendin-4 (Ex-4), and the 5-HT2c receptor agonist Ro60-0175 in male Sprague-Dawley rats. Following training on a progressive ratio 3 (PR3) schedule, animals were first injected with ghrelin into the VTA at doses of 3 to 300 pmol. In subsequent testing, separate rats were administered intraperitoneal (IP) Ex-4 (0.1–1.0 µg/kg) or VTA Ex-4 (0.01–0.1 µg) paired with 300 pmol ghrelin. In a final group of rats, the 5-HT2c agonist Ro60-0175 was injected IP (0.25–1.0 mg/kg) or into the VTA (1.5–3.0 µg), and under both conditions paired with 300 pmol ghrelin delivered into the VTA. Our results indicated that ghrelin administration increased operant responding for food reward and that this effect was attenuated by IP and VTA Ex-4 pretreatment as well as pre-administration of IP or VTA Ro60-0175. These data provide compelling evidence that mesolimbic GLP-1 and serotonergic circuitry interact with the ghrelinergic system to suppress ghrelin’s effects on the mediation of food reinforcement.
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Zhong H, Dang J, Huo Z, Ma Z, Chen J, Huang Y, Zhu Y, Li M. Effects of medial prefrontal cortex 5-HT 7 receptor knockdown on cognitive control after acute heroin administration. Brain Res 2017; 1678:419-431. [PMID: 29155092 DOI: 10.1016/j.brainres.2017.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 10/28/2017] [Accepted: 11/01/2017] [Indexed: 10/18/2022]
Abstract
Heroin abuse is linked to a deleterious effect on cognitive functioning in the individual. Recent evidences suggest that the serotonin7 receptor (5-HT7R) is engaged in the regulation of cognitive control and the drug use-associated behaviors. However, the role of 5-HT7R in the cognitive control after acute heroin administration has not been studied. The present study aims to investigate whether the knockdown of the 5-HT7R by virus-mediated gene silencing in the medial prefrontal cortex (mPFC) could ameliorate the acute heroin-induced cognitive impairments. The attentional function, impulsivity and compulsivity were assessed by the 5-choice serial reaction time task (5-CSRTT) in mice. The memory ability and locomotor activity were examined by the novel objects recognition (NOR), Y-maze and open-field test (OFT). Acute heroin administration at 5 mg/kg produced robust disruptions in attention, impulsivity and motivation in mice. 5-HT7R knockdown in the mPFC did not affect the 5-CSRTT baseline performance, spatial working memory, visual episodic memory and locomotion. However, mPFC 5-HT7R knockdown selectively ameliorated acute heroin-induced increase in omissions and premature responses under conditions of increased perceptual load. In addition, mPFC 5-HT7R knockdown induced increases in perseverative responding observed across both saline and heroin-treated animals. Moreover, 5-HT7R knockdown prevented the heroin-induced decrease in NR1/CaMKII phosphorylation in mPFC, thus suggesting that 5-HT7R and N-methyl-d-aspartic acid (NMDA) receptor signaling may be involved in the cognitive outcomes of acute heroin administration. Altogether, these observations suggest modest and restricted effects of mPFC 5-HT7R knockdown on cognitive behaviors, both in the presence or absence of acute heroin treatment.
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Affiliation(s)
- Huijun Zhong
- Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education & Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Ningxia Medical University, China
| | - Jie Dang
- Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education & Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Ningxia Medical University, China
| | - Zhenghao Huo
- Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education & Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Ningxia Medical University, China.
| | - Zhanbing Ma
- Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education & Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Ningxia Medical University, China
| | - Jing Chen
- Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education & Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Ningxia Medical University, China
| | - Yong Huang
- Department of Nuclear Medicine, Tangdu Hospital, The Fourth Military Medical University, China
| | - Yongsheng Zhu
- College of Forensic Science, Xi'an Jiao Tong University, China
| | - Min Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, China
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Bregman T, Nona C, Volle J, Diwan M, Raymond R, Fletcher PJ, Nobrega JN, Hamani C. Deep brain stimulation induces antidepressant-like effects in serotonin transporter knockout mice. Brain Stimul 2017; 11:423-425. [PMID: 29174865 DOI: 10.1016/j.brs.2017.11.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/25/2017] [Accepted: 11/14/2017] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Some of the antidepressant-like effects of ventromedial prefrontal cortex (vmPFC) deep brain stimulation (DBS) in rodents have been attributed to the modulation of prefrontal-raphe pathways. This is largely different from selective serotonin reuptake inhibitors (SSRIs), which increase serotonin (5-HT) levels by inhibiting the serotonin transporter (SERT). SSRIs have limited efficacy when given to SERT knockout (KO) mice, or patients with mutations in the serotonin transporter promoter gene (5-HTTLPR). HYPOTHESIS vmPFC DBS will induce antidepressant-like effects and serotonin release in SERT KOs. RESULTS DBS-treated wild-type and SERT KO mice had a significant 22-26% decrease in immobility in the forced swim test. DBS delivered to either group was associated with 33-55% increase in 5-HT levels. CONCLUSIONS DBS induced a significant antidepressant-like effect in KO mice. This suggests that it may be reasonable to consider DBS in states where SERT is not fully operational.
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Affiliation(s)
- Tatiana Bregman
- Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Christina Nona
- Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Julien Volle
- Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Mustansir Diwan
- Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Roger Raymond
- Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Paul J Fletcher
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Biopsychology Section, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - José N Nobrega
- Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada
| | - Clement Hamani
- Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada; Centre of Neuromodulation, Hurvitz Brain Science Program, Sunnybrook Research Institute, University of Toronto, 2075 Bayview Ave, Toronto, ON, M4N 3M5, Canada.
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Browne CJ, Ji X, Higgins GA, Fletcher PJ, Harvey-Lewis C. Pharmacological Modulation of 5-HT 2C Receptor Activity Produces Bidirectional Changes in Locomotor Activity, Responding for a Conditioned Reinforcer, and Mesolimbic DA Release in C57BL/6 Mice. Neuropsychopharmacology 2017; 42:2178-2187. [PMID: 28720903 PMCID: PMC5603805 DOI: 10.1038/npp.2017.124] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/03/2017] [Accepted: 06/07/2017] [Indexed: 11/09/2022]
Abstract
Converging lines of behavioral, electrophysiological, and biochemical evidence suggest that 5-HT2C receptor signaling may bidirectionally influence reward-related behavior through an interaction with the mesolimbic dopamine (DA) system. Here we directly test this hypothesis by examining how modulating 5-HT2C receptor activity affects DA-dependent behaviors and relate these effects to changes in nucleus accumbens (NAc) DA release. In C57BL/6 mice, locomotor activity and responding for a conditioned reinforcer (CRf), a measure of incentive motivation, were examined following treatment with three 5-HT2C receptor ligands: the agonist CP809101 (0.25-3 mg/kg), the antagonist SB242084 (0.25-1 mg/kg), or the antagonist/inverse agonist SB206553 (1-5 mg/kg). We further tested whether doses of these compounds that changed locomotor activity and responding for a CRf (1 mg/kg CP809101, 0.5 mg/kg SB242084, or 2.5 mg/kg SB206553) also altered NAc DA release using in vivo microdialysis in anesthetized mice. CP809101 reduced locomotor activity, responding for a CRf, and NAc DA release. In contrast, both SB242084 and SB206553 enhanced locomotor activity, responding for a CRf, and NAc DA release, although higher doses of SB206553 produced opposite behavioral effects. Pretreatment with the non-selective DA receptor antagonist α-flupenthixol prevented SB242084 from enhancing responding for a CRf. Thus blocking tonic 5-HT2C receptor signaling can release serotonergic inhibition of mesolimbic DA activity and enhance reward-related behavior. The observed bidirectional effects of 5-HT2C receptor ligands may have important implications when considering the 5-HT2C receptor as a therapeutic target for psychiatric disorders, particularly those presenting with motivational dysfunctions.
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Affiliation(s)
- Caleb J Browne
- Section of Biopsychology, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada,Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Xiaodong Ji
- Section of Biopsychology, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Guy A Higgins
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada,InterVivo Solutions, Toronto, ON, Canada
| | - Paul J Fletcher
- Section of Biopsychology, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada,Department of Psychology, University of Toronto, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada,Section of Biopsychology, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON M5T1R8, Canada, Tel: +1 416 535 8501 ex. 34058, Fax: +1 416 979 6942, E-mail:
| | - Colin Harvey-Lewis
- Section of Biopsychology, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
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Adams WK, Barkus C, Ferland JMN, Sharp T, Winstanley CA. Pharmacological evidence that 5-HT 2C receptor blockade selectively improves decision making when rewards are paired with audiovisual cues in a rat gambling task. Psychopharmacology (Berl) 2017; 234:3091-3104. [PMID: 28733811 DOI: 10.1007/s00213-017-4696-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/05/2017] [Indexed: 01/19/2023]
Abstract
RATIONALE Adding reward-concurrent cues to a rat gambling task (rGT) increases risky choice. This cued version of the task may reflect an "addiction-like" cognitive process, more similar to human gambling than the uncued task. Serotonergic drugs that target 5-HT2 receptors alter mechanisms linked to impulse control. However, relatively little is known regarding the impact of such agents on either risky decision making, or the ability of conditioned stimuli to bias the choice process, despite potential relevance to addiction development and treatment. OBJECTIVES The aim of this study was to determine the effects of SB 242,084 and M100907, selective antagonists at the 5-HT2C and 5-HT2A receptors respectively, as well as the selective 5-HT2C receptor agonist Ro-60-0175, on performance of both cued and uncued versions of the rGT. RESULTS SB 242,084 significantly and dose-dependently increased choice of the most optimal option in the cued rGT only, despite concurrently increasing impulsive responses made prematurely on both the cued and uncued rGT. M100907 and Ro-60-0175 did not alter risky decision making, but nevertheless produced the expected decrease in premature responses on both task variants. CONCLUSIONS These findings demonstrate that the 5-HT2 receptor-mediated regulation of risky decision making and motor impulsivity can be pharmacologically dissociated and further show that the presence of highly salient reward-paired cues critically alters the neurochemical regulation of the choice process. Importantly, these results suggest that 5-HT2C receptor antagonists may be of use in disrupting maladaptive patterns of decision making.
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Affiliation(s)
- Wendy K Adams
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Chris Barkus
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada.,Department of Pharmacology, University of Oxford, Oxford, UK
| | - Jacqueline-Marie N Ferland
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Catharine A Winstanley
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada.
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Effects of 5-HT 1A, 5-HT 2A and 5-HT 2C receptor agonists and antagonists on responding for a conditioned reinforcer and its enhancement by methylphenidate. Psychopharmacology (Berl) 2017; 234:889-902. [PMID: 28097374 DOI: 10.1007/s00213-017-4529-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 01/03/2017] [Indexed: 02/04/2023]
Abstract
OBJECTIVES These experiments examined the effects of selective 5-HT1A, 5-HT2A and 5-HT2C receptor ligands on responding for a conditioned reinforcer (CRf). Effects of these ligands were measured under basal conditions and following elevated dopamine (DA) activity produced by the DA reuptake inhibitor methylphenidate. METHODS Water-restricted rats learned to associate a conditioned stimulus (CS) with water in operant chambers. Subsequently, two response levers were made available; responding on one lever delivered the CS (now a CRf), while responding on the second lever had no consequences. The effects of agonist and antagonists of 5-HT1A (8-hydroxy-2(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT) and N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY100635)), 5-HT2A (DOI and M100907) and 5-HT2C (Ro60-0175 and SB242084) receptors on responding were examined alone, as well as in the presence of methylphenidate. RESULTS Responding for a CRf was reduced by the agonists 8-OH-DPAT, DOI and Ro60-0175. 8-OH-DPAT also reduced responding for water and seemed to impair responding in a non-specific fashion. None of the receptor antagonists affected responding. Methylphenidate dose-dependently enhanced responding for a CRf, and this was attenuated by DOI and Ro60-0175. Conversely, the 5-HT2C receptor antagonist SB242084 potentiated the effect of methylphenidate. CONCLUSIONS No evidence was found for a behaviourally selective effect of 5-HT1A receptor ligands on responding for a CRf. Activation of 5-HT2A receptors selectively inhibits responding for a CRf. 5-HT2C receptor ligands exerted bidirectional modulation of responding for a CRf, especially when DA activity was increased. This indicates that 5-HT2C receptor activity is an important modulator of DA-dependent reward-related behaviours.
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