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Liu Q, Deng Z, Chen H, Kim MS, Kim DH, Gu L, Lee JS, Yang Z. Changes in Induced-Antipredation Defense Traits and Transcriptome Regulations of Daphnia magna in Response to 5-HT 1A Receptor Antagonist. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:7577-7587. [PMID: 38630542 DOI: 10.1021/acs.est.3c10720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
The serotonin signaling system plays a crucial role in regulating the ontogeny of crustaceans. Here, we describe the effects of different concentrations of the 5-hydroxytryptamine 1A receptor antagonist (WAY-100635) on the induced antipredation (Rhodeus ocellatus as the predator), morphological, behavioral, and life-history defenses of Daphnia magna and use transcriptomics to analyze the underlying molecular mechanisms. Our results indicate that exposure to WAY-100635 leads to changes in the expression of different defensive traits in D. magna when faced with fish predation risks. Specifically, as the length of exposure to WAY-100635 increases, high concentrations of WAY-100635 inhibit defensive responses associated with morphological and reproductive activities but promote the immediate negative phototactic behavioral defense of D. magna. This change is related to the underlying mechanism through which WAY-100635 interferes with gene expression of G-protein-coupled GABA receptors by affecting GABBR1 but promotes serotonin receptor signaling and ecdysteroid signaling pathways. In addition, we also find for the first time that fish kairomone can significantly activate the HIF-1α signaling pathway, which may lead to an increase in the rate of immediate movement. These results can help assess the potential impacts of serotonin-disrupting psychotropic drugs on zooplankton in aquatic ecosystems.
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Affiliation(s)
- Qi Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China
| | - Ziyi Deng
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China
| | - Huafang Chen
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China
| | - Min-Sub Kim
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Duck-Hyun Kim
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Lei Gu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China
| | - Jae-Seong Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Zhou Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China
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Boucherie DE, Reneman L, Booij J, Martins D, Dipasquale O, Schrantee A. Modulation of functional networks related to the serotonin neurotransmitter system by citalopram: Evidence from a multimodal neuroimaging study. J Psychopharmacol 2023; 37:1209-1217. [PMID: 37947344 PMCID: PMC10714691 DOI: 10.1177/02698811231211154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
BACKGROUND Selective serotonin reuptake inhibitors (SSRIs) potentiate serotonergic neurotransmission by blocking the serotonin transporter (5-HTT), but the functional brain response to SSRIs involves neural circuits beyond regions with high 5-HTT expression. Currently, it is unclear whether and how changes in 5-HTT availability after SSRI administration modulate brain function of key serotoninergic circuits, including those characterized by high availability of the serotonin 1A receptor (5-HT1AR). AIM We investigated the association between 5-HTT availability and 5-HTT- and 5-HT1AR-enriched functional connectivity (FC) after an acute citalopram challenge. METHODS We analyzed multimodal data from a dose-response, placebo-controlled, double-blind study, in which 45 healthy women were randomized into three groups receiving placebo, a low (4 mg), or high (16 mg) oral dose of citalopram. Receptor-Enhanced Analysis of functional Connectivity by Targets was used to estimate 5-HTT- and 5-HT1AR-enriched FC from resting-state and task-based fMRI. 5-HTT availability was determined using [123I]FP-CIT single-photon emission computerized tomography. RESULTS 5-HTT availability was negatively correlated with resting-state 5-HTT-enriched FC, and with task-dependent 5-HT1AR-enriched FC. Our exploratory analyses revealed lower 5-HT1AR-enriched FC in the low-dose group compared to the high-dose group at rest and the placebo group during the emotional face-matching task. CONCLUSIONS Taken together, our findings provide evidence for differential links between 5-HTT availability and brain function within 5-HTT and 5-HT1AR pathways and in context- and dose-dependent manner. As such, they support a potential pivotal role of the 5-HT1AR in the effects of citalopram on the brain and add to its potential as a therapeutic avenue for mood and anxiety disturbances.
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Affiliation(s)
- Daphne E Boucherie
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location Amsterdam Medical Center, Amsterdam, The Netherlands
| | - Liesbeth Reneman
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location Amsterdam Medical Center, Amsterdam, The Netherlands
| | - Jan Booij
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location Amsterdam Medical Center, Amsterdam, The Netherlands
| | - Daniel Martins
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Division of Adult Psychiatry, Department of Psychiatry, Geneva University Hospitals, Geneva, Switzerland
| | - Ottavia Dipasquale
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Anouk Schrantee
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location Amsterdam Medical Center, Amsterdam, The Netherlands
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Kamishoyosan Alleviates Anxiety-like Behavior in a Premenstrual Syndrome Rat Model. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:2801784. [PMID: 36276857 PMCID: PMC9586730 DOI: 10.1155/2022/2801784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/25/2022] [Accepted: 08/29/2022] [Indexed: 11/18/2022]
Abstract
Kamishoyosan (KSS) is a traditional Japanese Kampo medicine that is prescribed for hormonal change-induced mood disorders including premenstrual syndrome (PMS). In clinical studies, KSS exhibited ameliorative effects on mood symptoms of PMS, such as anxiety and irritability. However, the mechanism underlying the beneficial effects of KSS is unclear. In the present study, we investigated the involvement of serotonergic machinery in the anxiolytic effects of KSS on hormonally-induced anxiety-like behavior in progesterone withdrawal (PWD) rats, which were used as a model of PMS. Female rats were injected with progesterone daily for 21 days. At 48 h after the final progesterone injection, anxiety-like behavior was evaluated using the elevated plus maze. KSS was administered orally to PWD rats 1 h prior to the test and significantly attenuated PWD-induced anxiety-like behavior. This ameliorative effect of KSS was reversed by WAY-100635, a serotonin (5-HT)1A receptor antagonist. The effect of KSS on serotonergic transmission in the prefrontal cortex of PWD rats was also evaluated using an in vivo microdialysis procedure. KSS significantly increased the extracellular 5-HT level in the prefrontal cortex of PWD rats. In conclusion, our results suggest that KSS alleviates PWD-induced anxiety-like behavior at least partly by activating 5-HT1A receptors and enhancing serotonergic transmission.
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Mony TJ, Elahi F, Choi JW, Park SJ. Neuropharmacological Effects of Terpenoids on Preclinical Animal Models of Psychiatric Disorders: A Review. Antioxidants (Basel) 2022; 11:antiox11091834. [PMID: 36139909 PMCID: PMC9495487 DOI: 10.3390/antiox11091834] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022] Open
Abstract
Terpenoids are widely distributed in nature, especially in the plant kingdom, and exhibit diverse pharmacological activities. In recent years, screening has revealed a wide variety of new terpenoids that are active against different psychiatric disorders. This review synthesized the current published preclinical studies of terpenoid use in psychiatric disorders. This review was extensively investigated to provide empirical evidence regarding the neuropharmacological effects of the vast group of terpenoids in translational models of psychiatric disorders, their relevant mechanisms of action, and treatment regimens with evidence of the safety and psychotropic efficacy. Therefore, we utilized nine (9) electronic databases and performed manual searches of each. The relevant data were retrieved from the articles published until present. We used the search terms "terpenoids" or "terpenes" and "psychiatric disorders" ("psychiatric disorders" OR "psychiatric diseases" OR "neuropsychiatric disorders" OR "psychosis" OR "psychiatric symptoms"). The efficacy of terpenoids or biosynthetic compounds in the terpenoid group was demonstrated in preclinical animal studies. Ginsenosides, bacosides, oleanolic acid, asiatic acid, boswellic acid, mono- and diterpenes, and different forms of saponins and triterpenoids were found to be important bioactive compounds in several preclinical studies of psychosis. Taken together, the findings of the present review indicate that natural terpenoids and their derivatives could achieve remarkable success as an alternative therapeutic option for alleviating the core or associated behavioral features of psychiatric disorders.
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Affiliation(s)
- Tamanna Jahan Mony
- Agriculture and Life Science Research Institute, Kangwon National University, Chuncheon 24341, Korea
| | - Fazle Elahi
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon 24341, Korea
| | - Ji Woong Choi
- College of Pharmacy, Gachon University, Incheon 21936, Korea
- Correspondence: (J.W.C.); (S.J.P.); Tel.: +82-32-820-4955 (J.W.C.); +82-33-250-6441 (S.J.P.); Fax: +82-32-820-4829 (J.W.C.); +82-33-259-5563 (S.J.P.)
| | - Se Jin Park
- School of Natural Resources and Environmental Sciences and Agriculture and Life Science Research Institute, Kangwon National University, Chuncheon 24341, Korea
- Correspondence: (J.W.C.); (S.J.P.); Tel.: +82-32-820-4955 (J.W.C.); +82-33-250-6441 (S.J.P.); Fax: +82-32-820-4829 (J.W.C.); +82-33-259-5563 (S.J.P.)
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5
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5-HT Receptors and the Development of New Antidepressants. Int J Mol Sci 2021; 22:ijms22169015. [PMID: 34445721 PMCID: PMC8396477 DOI: 10.3390/ijms22169015] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 02/06/2023] Open
Abstract
Serotonin modulates several physiological and cognitive pathways throughout the human body that affect emotions, memory, sleep, and thermal regulation. The complex nature of the serotonergic system and interactions with other neurochemical systems indicate that the development of depression may be mediated by various pathomechanisms, the common denominator of which is undoubtedly the disturbed transmission in central 5-HT synapses. Therefore, the deliberate pharmacological modulation of serotonergic transmission in the brain seems to be one of the most appropriate strategies for the search for new antidepressants. As discussed in this review, the serotonergic system offers great potential for the development of new antidepressant therapies based on the combination of SERT inhibition with different pharmacological activity towards the 5-HT system. The aim of this article is to summarize the search for new antidepressants in recent years, focusing primarily on the possibility of benefiting from interactions with various 5-HT receptors in the pharmacotherapy of depression.
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Kesić M, Mokrović G, Tvrdeić A, Miše B, Štefulj J, Čičin-Šain L. Constitutive Serotonin Tone Modulates Molecular and Behavioral Response to Chronic Fluoxetine Treatment: A Study on Genetic Rat Model. Front Psychiatry 2021; 12:741222. [PMID: 34658974 PMCID: PMC8517234 DOI: 10.3389/fpsyt.2021.741222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/06/2021] [Indexed: 11/16/2022] Open
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed medications for the treatment of mood disorders. Yet, individual response to SSRIs is highly variable, with only a portion of patients showing the desired therapeutic effect. To better understand the molecular basis underlying individual variability in response to SSRIs, here we comparatively studied behavioral and molecular consequences of chronic treatment with fluoxetine, a widely used SSRI, in two sublines of rats with constitutionally different serotonin (5HT) homeostasis: the high-5HT and low-5HT sublines. Platelet 5HT levels, a recognized indicator of SSRI efficacy, were decreased by fluoxetine treatment in both 5HT-sublines. On the other hand, biologically active plasma 5HT levels were reduced only in high-5HT rats. The anxiolytic effect of fluoxetine was also evident only in high-5HT rats, as supported by spatio-temporal and ethological behavioral measures in the elevated plus maze (EPM) test and exploratory behavior measures in the open field (OF) test. None of the behavioral EPM or OF measures were significantly altered by fluoxetine treatment in low-5HT rats. Unexpectedly, 5HT levels in cerebral cortices tended to be reduced only in low-5HT rats. Moreover, the effects of fluoxetine on cortical expression levels of 5HT-related proteins were also present only in low-5HT rats, with serotonin transporter (5HTT) and serotonin receptor type 1a (Htr1a) being down-regulated, while serotonin receptor type 4 (Htr4) was up-regulated by fluoxetine treatment. The obtained results support a role of individual 5HT tone as an important influencing factor on the biological actions of SSRI antidepressants.
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Affiliation(s)
- Maja Kesić
- Laboratory for Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Gordana Mokrović
- Laboratory for Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Ante Tvrdeić
- Department of Pharmacology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Branko Miše
- University Hospital for Infectious Diseases, Zagreb, Croatia
| | - Jasminka Štefulj
- Laboratory for Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Lipa Čičin-Šain
- Laboratory for Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
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Garro-Martínez E, Vidal R, Adell A, Díaz Á, Castro E, Amigó J, Gutiérrez-Lanza R, Florensa-Zanuy E, Gómez-Acero L, Taketo MM, Pazos Á, Pilar-Cuéllar F. β-Catenin Role in the Vulnerability/Resilience to Stress-Related Disorders Is Associated to Changes in the Serotonergic System. Mol Neurobiol 2019; 57:1704-1715. [DOI: 10.1007/s12035-019-01841-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 11/22/2019] [Indexed: 01/02/2023]
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8
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Montalbano A, Mlinar B, Bonfiglio F, Polenzani L, Magnani M, Corradetti R. Dual inhibitory action of trazodone on dorsal raphe serotonergic neurons through 5-HT1A receptor partial agonism and α1-adrenoceptor antagonism. PLoS One 2019; 14:e0222855. [PMID: 31557210 PMCID: PMC6763016 DOI: 10.1371/journal.pone.0222855] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/09/2019] [Indexed: 11/19/2022] Open
Abstract
Trazodone is an antidepressant drug with considerable affinity for 5-HT1A receptors and α1-adrenoceptors for which the drug is competitive agonist and antagonist, respectively. In this study, we used cell-attached or whole-cell patch-clamp recordings to characterize the effects of trazodone at somatodendritic 5-HT1A receptors (5-HT1AARs) and α1-adrenoceptors of serotonergic neurons in rodent dorsal raphe slices. To reveal the effects of trazodone at α1-adrenoceptors, the baseline firing of 5-HT neurons was facilitated by applying the selective α1-adrenoceptor agonist phenylephrine at various concentrations. In the absence of phenylephrine, trazodone (1–10 μM) concentration-dependently silenced neurons through activation of 5-HT1AARs. The effect was fully antagonized by the selective 5-HT1A receptor antagonist Way-100635. With 5-HT1A receptors blocked by Way-100635, trazodone (1–10 μM) concentration-dependently inhibited neuron firing facilitated by 1 μM phenylephrine. Parallel rightward shift of dose-response curves for trazodone recorded in higher phenylephrine concentrations (10–100 μM) indicated competitive antagonism at α1-adrenoceptors. Both effects of trazodone were also observed in slices from Tph2-/- mice that lack synthesis of brain serotonin, showing that the activation of 5-HT1AARs was not mediated by endogenous serotonin. In whole-cell recordings, trazodone activated 5-HT1AAR-coupled G protein-activated inwardly-rectifying (GIRK) channel conductance with weak partial agonist efficacy (~35%) compared to that of the full agonist 5-CT. Collectively our data show that trazodone, at concentrations relevant to its clinical effects, exerts weak partial agonism at 5-HT1AARs and disfacilitation of firing through α1-adrenoceptor antagonism. These two actions converge in inhibiting dorsal raphe serotonergic neuron activity, albeit with varying contribution depending on the intensity of α1-adrenoceptor stimulation.
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Affiliation(s)
- Alberto Montalbano
- NEUROFARBA—Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Università di Firenze, Firenze, Italia
| | - Boris Mlinar
- NEUROFARBA—Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Università di Firenze, Firenze, Italia
| | - Francesco Bonfiglio
- NEUROFARBA—Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Università di Firenze, Firenze, Italia
| | - Lorenzo Polenzani
- Angelini RR&D (Research, Regulatory & Development), Angelini S.p.A, S.Palomba-Pomezia (Roma), Italia
| | - Maurizio Magnani
- Angelini RR&D (Research, Regulatory & Development), Angelini S.p.A, S.Palomba-Pomezia (Roma), Italia
| | - Renato Corradetti
- NEUROFARBA—Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino, Università di Firenze, Firenze, Italia
- * E-mail:
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Tritschler L, Gaillard R, Gardier AM, David DJ, Guilloux JP. [Consequences of the monoaminergic systems cross-talk in the antidepressant activity]. Encephale 2018; 44:264-273. [PMID: 29801770 DOI: 10.1016/j.encep.2018.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/30/2018] [Indexed: 12/27/2022]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed antidepressant treatment for treat major depressive disorders. Despite their effectiveness, only 30% of SSRI-treated patients reach remission of depressive symptoms. SSRIs by inhibiting the serotonin transporter present some limits with residual symptoms. Increasing not only serotonin but also norepinephrine and dopamine levels in limbic areas seems to improve remission. Anatomical relationships across serotoninergic, dopaminergic and noradrenergic systems suggest tight reciprocal regulations among them. This review attempts to present, from acute to chronic administration the consequences of SSRI administration on monoaminergic neurotransmission. The serotonin neurons located in the raphe nucleus (RN) are connected to the locus coeruleus (locus coeruleus), the key structure of norepinephrine synthesis, through GABAergic-inhibiting interneurons. Activation of the 5-HT2A receptors expressed on GABAergic interneurons following SERT-inhibition induces an increase in serotonin leading to inhibitory effect on NE release. Similarly, the serotonin neurons exert negative regulation on dopaminergic neurons from the ventral tegmental area (VTA) through a GABAergic interneuron. These interneurons express the 5-HT2C and 5-HT3 receptors inducing an inhibitory effect of 5-HT on DA release. Positive reciprocal connections are also observed through direct projections from the locus coeruleus to the RN and from the VTA to the RN through α1 and D2 receptors respectively, both stimulating the serotoninergic activity. Acute SSRI treatment induces only a slight increase in 5-HT levels in limbic areas due to the activation of presynaptic 5-HT1A and 5-HT1B autoreceptors counteracting the effects of the transporter blockade. No change in NE levels and a small decrease in the dopaminergic neurotransmission is also observed. These weak changes in monoamine in the limbic areas after acute SSRI treatment seems to be one of key point involved in the onset of action. Following desensitization of the 5-HT1A and 5-HT1B autoreceptors, chronic SSRI treatment induces a large increase in the 5-HT neurotransmission. Changes in 5-HT levels at the limbic areas results in a decrease in NE transmission and an increase in DA transmission through an increase in the post-synaptic D2 receptors sensitivity and not from a change in DA levels, which is mainly due to a desensitization of the 5-HT2A receptor. The observed decrease of NE neurotransmission could explain some limits of the SSRI therapy and the interest to activate NE system for producing more robust effects. On the other hand, the D2 sensitization, especially in the nucleus accumbens, stimulates the motivation behavior as well as remission of anhedonia considering the major role of DA release in this structure. Finally, we need to take into account the key role of each monoaminergic neurotransmission to reach remission. Targeting only one system will limit the therapeutic effectiveness. Clinical evidences, including the STAR*D studies, confirmed this by an increase of the remission rate following the mobilization of several monoaminergic transmissions. However, these combinations cannot constitute first line of treatment considering the observed increase of side effects. Such an approach should be adapted to each patient in regard to its particular symptoms as well as clinical history. The next generation of antidepressant therapy will need to take into consideration the interconnections and the interrelation between the monoaminergic systems.
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Affiliation(s)
- L Tritschler
- CESP, Inserm UMRS1178, faculté de pharmacie, université Paris-Saclay, université Paris-Sud, 92296 Chatenay-Malabry, France
| | - R Gaillard
- Inserm UMR 894, centre de psychiatrie & neurosciences, CNRS GDR 3557, institut de psychiatrie, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75015 Paris, France; Service hospitalo-universitaire, centre hospitalier Sainte-Anne, 75015 Paris, France
| | - A M Gardier
- CESP, Inserm UMRS1178, faculté de pharmacie, université Paris-Saclay, université Paris-Sud, 92296 Chatenay-Malabry, France
| | - D J David
- CESP, Inserm UMRS1178, faculté de pharmacie, université Paris-Saclay, université Paris-Sud, 92296 Chatenay-Malabry, France.
| | - J-P Guilloux
- CESP, Inserm UMRS1178, faculté de pharmacie, université Paris-Saclay, université Paris-Sud, 92296 Chatenay-Malabry, France.
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Artigas F, Bortolozzi A, Celada P. Can we increase speed and efficacy of antidepressant treatments? Part I: General aspects and monoamine-based strategies. Eur Neuropsychopharmacol 2018; 28:445-456. [PMID: 29174531 DOI: 10.1016/j.euroneuro.2017.10.032] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 07/03/2017] [Accepted: 10/22/2017] [Indexed: 12/21/2022]
Abstract
Major depressive disorder (MDD) is a severe psychiatric syndrome with high prevalence and socioeconomic impact. Current antidepressant treatments are based on the blockade of serotonin (5-hydroxytryptamine, 5-HT) and/or noradrenaline transporters. These drugs show slow onset of clinical action and limited efficacy, partly due to the activation of physiological negative feed-back mechanisms operating through autoreceptors (5-HT1A, 5-HT1B, α2-adrenoceptors) and postsynaptic receptors (e.g., 5-HT3). As a result, clinically-relevant doses of reuptake inhibitors increase extracellular (active) 5-HT concentrations in the midbrain raphe nuclei but not in forebrain, as indicated by rodent microdialysis studies and by PET-scan studies in primate/human brain. The prevention of these self-inhibitory mechanisms by antagonists of the above receptors augments preclinical and clinical antidepressant effects. Hence, the mixed ß-adrenoceptor/5-HT1A antagonist pindolol accelerated, and in some cases enhanced, the clinical action of selective serotonin reuptake inhibitors (SSRI). This strategy has been incorporated into two new multi-target antidepressant drugs, vilazodone and vortioxetine, which combine 5-HT reuptake inhibition and partial agonism at 5-HT1A receptors. Vortioxetine shows also high affinity for other 5-HT receptors, including excitatory 5-HT3 receptors located in cortical and hippocampal GABA interneurons. 5-HT3 receptor blockade by vortioxetine enhances pyramidal neuron activity in prefrontal cortex as well as cortical and hippocampal 5-HT release. It is still too soon to know whether these new antidepressants will represent a real advance over existing drugs in the real world. However, their development opened the way to future antidepressant drugs based on the prevention of local and distal self-inhibitory mechanisms attenuating monoamine activity.
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Affiliation(s)
- Francesc Artigas
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Spain; CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.
| | - Analia Bortolozzi
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Spain; CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain
| | - Pau Celada
- Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Spain; CIBERSAM (Centro de Investigación Biomédica en Red de Salud Mental), Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain
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11
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Mitra S, Mucha M, Owen S, Bult-Ito A. Postpartum Lactation-Mediated Behavioral Outcomes and Drug Responses in a Spontaneous Mouse Model of Obsessive-Compulsive Disorder. ACS Chem Neurosci 2017; 8:2683-2697. [PMID: 28945961 DOI: 10.1021/acschemneuro.7b00231] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Using a spontaneous mouse model of obsessive-compulsive disorder (OCD), the current study evaluated the influence of postpartum lactation on the expression of compulsive-like behaviors, SSRI effectiveness, and the putative role of oxytocin and dopamine in mediating these lactation specific behavioral outcomes. Compulsive-like lactating mice were less compulsive-like in nest building and marble burying and showed enhanced responsiveness to fluoxetine (50 mg/kg) in comparison to compulsive-like nonlactating and nulliparous females. Lactating mice exhibited more anxiety-like behavior in the open field test compared to the nulliparous females, while chronic fluoxetine reduced anxiety-like behaviors. Blocking the oxytocin receptor with L368-899 (5 mg/kg) in the lactating mice exacerbated the compulsive-like and depression-like behaviors. The dopamine D2 receptor (D2R) agonist bromocriptine (10 mg/kg) suppressed marble burying, nest building, and central entries in the open field, but because it also suppressed overall locomotion in the open field, activation of the D2R receptor may have inhibited overall activity nonspecifically. Lactation- and fluoxetine-mediated behavioral outcomes in compulsive-like mice, therefore, appear to be partly regulated by oxytocinergic mechanisms. Serotonin immunoreactivity and serum levels were higher in lactating compulsive-like mice compared to nonlactating and nulliparous compulsive-like females. Together, these results suggest behavioral modulation, serotonergic alterations, and changes in SSRI effectiveness during lactation in compulsive-like mice. This warrants further investigation of postpartum events in OCD patients.
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Affiliation(s)
- Swarup Mitra
- Department
of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
- IDeA
Network of Biomedical Research Excellence (INBRE), University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - McKenzie Mucha
- Department
of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - Savanah Owen
- Department of Biology & Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
| | - Abel Bult-Ito
- Department of Biology & Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
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12
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Kjaerby C, Athilingam J, Robinson SE, Iafrati J, Sohal VS. Serotonin 1B Receptors Regulate Prefrontal Function by Gating Callosal and Hippocampal Inputs. Cell Rep 2017; 17:2882-2890. [PMID: 27974203 DOI: 10.1016/j.celrep.2016.11.036] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 10/03/2016] [Accepted: 11/10/2016] [Indexed: 12/29/2022] Open
Abstract
Both medial prefrontal cortex (mPFC) and serotonin play key roles in anxiety; however, specific mechanisms through which serotonin might act on the mPFC to modulate anxiety-related behavior remain unknown. Here, we use a combination of optogenetics and synaptic physiology to show that serotonin acts presynaptically via 5-HT1B receptors to selectively suppress inputs from the contralateral mPFC and ventral hippocampus (vHPC), while sparing those from mediodorsal thalamus. To elucidate how these actions could potentially regulate prefrontal circuit function, we infused a 5-HT1B agonist into the mPFC of freely behaving mice. Consistent with previous studies that have optogenetically inhibited vHPC-mPFC projections, activating prefrontal 5-HT1B receptors suppressed theta-frequency mPFC activity (4-12 Hz), and reduced avoidance of anxiogenic regions in the elevated plus maze. These findings suggest a potential mechanism, linking specific receptors, synapses, patterns of circuit activity, and behavior, through which serotonin may regulate prefrontal circuit function, including anxiety-related behaviors.
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Affiliation(s)
- Celia Kjaerby
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan-Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Jegath Athilingam
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan-Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Sarah E Robinson
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan-Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Jillian Iafrati
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan-Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Vikaas S Sohal
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan-Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA.
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13
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Asaoka N, Nishitani N, Kinoshita H, Kawai H, Shibui N, Nagayasu K, Shirakawa H, Nakagawa T, Kaneko S. Chronic antidepressant potentiates spontaneous activity of dorsal raphe serotonergic neurons by decreasing GABA B receptor-mediated inhibition of L-type calcium channels. Sci Rep 2017; 7:13609. [PMID: 29051549 PMCID: PMC5648823 DOI: 10.1038/s41598-017-13599-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/26/2017] [Indexed: 12/13/2022] Open
Abstract
Spontaneous activity of serotonergic neurons of the dorsal raphe nucleus (DRN) regulates mood and motivational state. Potentiation of serotonergic function is one of the therapeutic strategies for treatment of various psychiatric disorders, such as major depression, panic disorder and obsessive-compulsive disorder. However, the control mechanisms of the serotonergic firing activity are still unknown. In this study, we examined the control mechanisms for serotonergic spontaneous activity and effects of chronic antidepressant administration on these mechanisms by using modified ex vivo electrophysiological recording methods. Serotonergic neurons remained firing even in the absence of glutamatergic and GABAergic ionotropic inputs, while blockade of L-type voltage dependent Ca2+ channels (VDCCs) in serotonergic neurons decreased spontaneous firing activity. L-type VDCCs in serotonergic neurons received gamma-aminobutyric acid B (GABAB) receptor-mediated inhibition, which maintained serotonergic slow spontaneous firing activity. Chronic administration of an antidepressant, citalopram, disinhibited the serotonergic spontaneous firing activity by weakening the GABAB receptor-mediated inhibition of L-type VDCCs in serotonergic neurons. Our results provide a new mechanism underlying the spontaneous serotonergic activity and new insights into the mechanism of action of antidepressants.
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Affiliation(s)
- Nozomi Asaoka
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Naoya Nishitani
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Haruko Kinoshita
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Hiroyuki Kawai
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Norihiro Shibui
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Kazuki Nagayasu
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Hisashi Shirakawa
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Takayuki Nakagawa
- Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Shuji Kaneko
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
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14
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Fritze S, Spanagel R, Noori HR. Adaptive dynamics of the 5-HT systems following chronic administration of selective serotonin reuptake inhibitors: a meta-analysis. J Neurochem 2017; 142:747-755. [PMID: 28653748 DOI: 10.1111/jnc.14114] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/20/2017] [Accepted: 06/20/2017] [Indexed: 02/05/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the most frequently prescribed antidepressants. However, a major concern is their delayed onset of action, which is hypothesized to be associated with the time required for serotonin (5-HT) autoreceptors to desensitize, which should be reflected by actual neurochemical changes. Numerous in vivo microdialysis studies have been published that report on 5-HT levels in different brain sites following SSRI administration. Here, we performed a meta-analysis on dynamic changes of 5-HT neurotransmission during the course of chronic SSRI treatment. We conducted a meta-analysis on research articles of 5-HT neurotransmission measured by in vivo microdialysis in rat brain after subchronic and chronic SSRI administrations. In total, data from 42 microdialysis studies (798 rats) were analyzed. Within the first week of SSRI treatment, extracellular 5-HT concentrations drop in frontal cortex. Over the next 2 weeks of treatment, a linear increase in extracellular 5-HT levels up to 350% of prior treatment baseline is evident (n = 269). However, in hippocampus, prefrontal cortex, nucleus accumbens, and ventral tegmental area we found increased 5-HT levels within the first 3 days of SSRI administration. The time course of 5-HT dynamics in frontal cortex is in line with the hypothesis that 5-HT autoreceptors desensitize over 2-3 weeks of SSRI treatment and thereby enhanced extracellular 5-HT levels ensue. Yet, in other regions we did not find evidence supporting the traditional autoreceptor-mediated feedback loops hypothesis and thus other neurobiological adaptation mechanisms may also play a role in the delayed onset of SSRI action.
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Affiliation(s)
- Stefan Fritze
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Hamid R Noori
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Neuronal Convergence Group, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
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15
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Raab K, Kirsch P, Mier D. Understanding the impact of 5-HTTLPR, antidepressants, and acute tryptophan depletion on brain activation during facial emotion processing: A review of the imaging literature. Neurosci Biobehav Rev 2016; 71:176-197. [DOI: 10.1016/j.neubiorev.2016.08.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 07/28/2016] [Accepted: 08/26/2016] [Indexed: 12/22/2022]
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16
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Hettie KS, Glass TE. Turn-On Near-Infrared Fluorescent Sensor for Selectively Imaging Serotonin. ACS Chem Neurosci 2016; 7:21-5. [PMID: 26521705 DOI: 10.1021/acschemneuro.5b00235] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A molecular imaging tool that provides for the direct visualization of serotonin would significantly aid in the investigation of neuropsychiatric disorders that are attributed to its neuronal dysregulation. Here, the design, synthesis, and evaluation of NeuroSensor 715 (NS715) is presented. NS715 is the first molecular sensor that exhibits a turn-on near-infrared fluorescence response toward serotonin. Density functional theory calculations facilitated the design of a fluorophore based on a coumarin-3-aldehyde scaffold that derives from an electron-rich 1,2,3,4-tetrahydroquinoxaline framework, which provides appropriate energetics to prevent the hydroxyindole moiety of serotonin from quenching its fluorescence emission. Spectroscopic studies revealed that NS715 produces an 8-fold fluorescence enhancement toward serotonin with an emission maximum at 715 nm. Accompanying binding studies indicated NS715 displays a 19-fold selective affinity for serotonin and a modest affinity for catecholamines over other primary-amine neurotransmitters. The utility of NS715 toward neuroimaging applications was validated by selectively labeling and directly imaging norepinephrine within secretory vesicles using live chromaffin cells, which serve as a model system for specialized neurons that synthesize, package, and release only a single, unique type of neurotransmitter. In addition, NS715 effectively differentiated between cell populations that express distinct neurotransmitter phenotypes.
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Affiliation(s)
- Kenneth S. Hettie
- Department
of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Timothy E. Glass
- Department
of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
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17
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Chilmonczyk Z, Bojarski AJ, Pilc A, Sylte I. Functional Selectivity and Antidepressant Activity of Serotonin 1A Receptor Ligands. Int J Mol Sci 2015; 16:18474-506. [PMID: 26262615 PMCID: PMC4581256 DOI: 10.3390/ijms160818474] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 07/29/2015] [Accepted: 07/31/2015] [Indexed: 01/11/2023] Open
Abstract
Serotonin (5-HT) is a monoamine neurotransmitter that plays an important role in physiological functions. 5-HT has been implicated in sleep, feeding, sexual behavior, temperature regulation, pain, and cognition as well as in pathological states including disorders connected to mood, anxiety, psychosis and pain. 5-HT1A receptors have for a long time been considered as an interesting target for the action of antidepressant drugs. It was postulated that postsynaptic 5-HT1A agonists could form a new class of antidepressant drugs, and mixed 5-HT1A receptor ligands/serotonin transporter (SERT) inhibitors seem to possess an interesting pharmacological profile. It should, however, be noted that 5-HT1A receptors can activate several different biochemical pathways and signal through both G protein-dependent and G protein-independent pathways. The variables that affect the multiplicity of 5-HT1A receptor signaling pathways would thus result from the summation of effects specific to the host cell milieu. Moreover, receptor trafficking appears different at pre- and postsynaptic sites. It should also be noted that the 5-HT1A receptor cooperates with other signal transduction systems (like the 5-HT1B or 5-HT2A/2B/2C receptors, the GABAergic and the glutaminergic systems), which also contribute to its antidepressant and/or anxiolytic activity. Thus identifying brain specific molecular targets for 5-HT1A receptor ligands may result in a better targeting, raising a hope for more effective medicines for various pathologies.
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Affiliation(s)
- Zdzisław Chilmonczyk
- National Medicines Institute, Chełmska 30/34, 00-725 Warszawa, Poland.
- Institute of Nursing and Health Sciences, University of Rzeszów, W. Kopisto 2A, 35-310 Rzeszów, Poland.
| | - Andrzej Jacek Bojarski
- Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Kraków, Poland.
| | - Andrzej Pilc
- Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Kraków, Poland.
| | - Ingebrigt Sylte
- Faculty of Health Sciences, University of Tromsø-The Arctic University of Norway, No-9037 Tromsø, Norway.
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18
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Rahn KA, Cao YJ, Hendrix CW, Kaplin AI. The role of 5-HT1A receptors in mediating acute negative effects of antidepressants: implications in pediatric depression. Transl Psychiatry 2015; 5:e563. [PMID: 25942044 PMCID: PMC4471288 DOI: 10.1038/tp.2015.57] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 01/20/2015] [Accepted: 02/10/2015] [Indexed: 01/20/2023] Open
Abstract
Acute antidepressant exposure elevates the frequency of impulsive behavior and suicidal thoughts in children and adolescents with major depressive disorder (MDD). Long-term antidepressant treatment, however, is beneficial for pediatric MDD, so it is necessary to explore novel treatments that prevent the potentially dangerous consequences of acute antidepressant initiation. In the present study, a treatment strategy designed to reverse the acute negative behavioral effects of antidepressants was tested in rodents. Co-administration of the 5-HT1A receptor (5-HT1AR) antagonist WAY-100635 reversed the negative effects of acute fluoxetine, a serotonin reuptake inhibitor, but not reboxetine, a norepinephrine reuptake inhibitor, supporting the involvement of 5-HT1AR in mediating the negative consequences of acute selective serotonin reuptake inhibitor (SSRI) treatment. No 5-HT1AR antagonists are currently approved for use in pediatric populations, so alternative strategies should be explored. One such strategy was suggested based on the hypothesis that the rate of 5-HT1AR activation and the subsequent inhibition of serotonergic neuron activity caused by acute SSRI administration is proportional to the loading rate of an antidepressant. Existing pharmacological data were examined, and significant correlations were observed between the half-life of antidepressants and the rate of suicide-related events (SREs). Specifically, antidepressants with longer half-lives have lower rates of SREs. On the basis of these data, novel dosing strategies were developed for five antidepressants to mimic the pharmacological profile of the antidepressant with the longest half-life, fluoxetine. These dosing strategies could be used to decrease the rate of SREs associated with acute antidepressant treatment in pediatric MDD until an improved pharmacological treatment is developed.
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Affiliation(s)
- K A Rahn
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA,Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - Y-J Cao
- Division of Clinical Pharmacology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - C W Hendrix
- Division of Clinical Pharmacology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - A I Kaplin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA,Department of Neurology, Johns Hopkins University, Baltimore, MD, USA,Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, 600 North Wolfe Street, Meyer 1-121, Baltimore 21287, MD, USA. E-mail:
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19
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Paracetamol potentiates the antidepressant-like and anticompulsive-like effects of fluoxetine. Behav Pharmacol 2015; 26:268-81. [DOI: 10.1097/fbp.0000000000000104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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20
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Dawson LA. The discovery and development of vilazodone for the treatment of depression: a novel antidepressant or simply another SSRI? Expert Opin Drug Discov 2013; 8:1529-39. [DOI: 10.1517/17460441.2013.855195] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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21
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Serotonin 5-HT1A receptors as targets for agents to treat psychiatric disorders: rationale and current status of research. CNS Drugs 2013; 27:703-16. [PMID: 23757185 DOI: 10.1007/s40263-013-0071-0] [Citation(s) in RCA: 224] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Psychiatric disorders represent a large economic burden in modern societies. However, pharmacological treatments are still far from optimal. Drugs used in the treatment of major depressive disorder (MDD) and anxiety disorders (selective serotonin [5-HT] reuptake inhibitors [SSRIs] and serotonin-noradrenaline reuptake inhibitors [SNRIs]) are pharmacological refinements of first-generation tricyclic drugs, discovered by serendipity, and show low efficacy and slowness of onset. Moreover, antipsychotic drugs are partly effective in positive symptoms of schizophrenia, yet they poorly treat negative symptoms and cognitive deficits. The present article reviews the neurobiological basis of 5-HT1A receptor (5-HT1A-R) function and the role of pre- and postsynaptic 5-HT1A-Rs in the treatment of MDD, anxiety and psychotic disorders. The activation of postsynaptic 5-HT1A-Rs in corticolimbic areas appears beneficial for the therapeutic action of antidepressant drugs. However, presynaptic 5-HT1A-Rs play a detrimental role in MDD, since individuals with high density or function of presynaptic 5-HT1A-Rs are more susceptible to mood disorders and suicide, and respond poorly to antidepressant drugs. Moreover, the indirect activation of presynaptic 5-HT1A-Rs by SSRIs/SNRIs reduces 5-HT neuron activity and terminal 5-HT release, thus opposing the elevation of extracellular 5-HT produced by blockade of the serotonin transporter (SERT) in the forebrain. Chronic antidepressant treatment desensitizes presynaptic 5-HT1A-Rs, thus reducing the effectiveness of the 5-HT1A autoreceptor-mediated negative feedback. The prevention of this process by the non-selective partial agonist pindolol accelerates clinical antidepressant effects. Two new antidepressant drugs, vilazodone (marketed in the USA) and vortioxetine (in development) incorporate partial 5-HT1A-R agonist properties with SERT blockade. Several studies with transgenic mice have also established the respective role of pre- and postsynaptic 5-HT1A-Rs in MDD and anxiety. In agreement with pharmacological studies, presynaptic and postsynaptic 5-HT1A-R activation appears necessary for anxiolytic and antidepressant effects, respectively, yet, neurodevelopmental roles for 5-HT1A-Rs are also involved. Likewise, the use of small interference RNA has enabled the showing of robust antidepressant-like effects in mice after selective knock-down of 5-HT1A autoreceptors. Postsynaptic 5-HT1A-Rs in the prefrontal cortex (PFC) also appear important for the superior clinical effects of clozapine and other second-generation (atypical) antipsychotic drugs in the treatment of schizophrenia and related psychotic disorders. Despite showing a moderate in vitro affinity for 5-HT1A-Rs in binding assays, clozapine displays functional agonist properties at this receptor type in vivo. The stimulation of 5-HT1A-Rs in the PFC leads to the distal activation of the mesocortical pathway and to an increased dopamine release in PFC, an effect likely involved in the clinical actions of clozapine in negative symptoms and cognitive deficits in schizophrenia. The anxiolytic/antidepressant properties of 5-HT1A-R agonists in preclinical tests raised expectations enormously. However, these agents have achieved little clinical success, possibly due to their partial agonist character at postsynaptic 5-HT1A-Rs, together with full agonist properties at presynaptic 5-HT1A autoreceptors, as well as their gastrointestinal side effects. The partial 5-HT1A-R agonists buspirone, gepirone, and tandospirone are marketed as anxiolytic drugs, and buspirone is also used as an augmentation strategy in MDD. The development of new 5-HT1A-R agonists with selectivity for postsynaptic 5-HT1A-Rs may open new perspectives in the field.
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22
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Woehrle NS, Klenotich SJ, Jamnia N, Ho EV, Dulawa SC. Effects of chronic fluoxetine treatment on serotonin 1B receptor-induced deficits in delayed alternation. Psychopharmacology (Berl) 2013; 227:545-51. [PMID: 23377022 DOI: 10.1007/s00213-013-2985-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 01/12/2013] [Indexed: 11/28/2022]
Abstract
RATIONALE Obsessive-compulsive disorder (OCD) patients show overactivation of the orbitofrontal cortex and deficits in cognitive tasks that require proper orbitofrontal functioning including delayed alternation tests of spatial working memory. We recently showed that OCD-like behavior is induced in mice by activating orbitofrontal serotonin 1B receptors (5-HT1Bs). However, the role of 5-HT1Bs in delayed alternation remains unclear. OBJECTIVES We examined the effects of 5-HT1B receptor activation on delayed alternation task (DAT) performance. We also assessed the ability of an effective OCD treatment, fluoxetine, to prevent 5-HT1B-induced deficits in DAT performance. METHODS Mice were tested on the DAT after acute treatment with saline, 3 or 6 mg/kg RU24969 (5-HT1B/1A agonist), 0.3 or 3 mg/kg 8-OH-DPAT (5-HT1A agonist), or co-injection with 3 mg/kg RU24969 and 5 mg/kg GR127935 (5-HT1B/1D antagonist). Separate mice were pretreated chronically (28 days) with 10 mg/kg fluoxetine and then tested on the DAT after acute treatment with 3 mg/kg RU24969, 0.3 mg/kg 8-OH-DPAT, or saline. RESULTS Both doses of RU24969 decreased accuracy and increased latency on the DAT, and GR127935 blocked RU24969-induced effects on accuracy. The 0.3 mg/kg 8-OH-DPAT did not affect the DAT performance, whereas 3 mg/kg increased omissions on the DAT. Finally, RU24969-induced DAT deficits were absent in fluoxetine-pretreated mice. CONCLUSIONS We show that 5-HT1B receptor activation disrupts DAT performance in mice, and chronic fluoxetine pretreatment blocks these 5-HT1B-induced deficits. Our findings suggest that 5-HT1B receptors play an important role in modulating orbitofrontal-dependent delayed alternation. Moreover, 5-HT1B-induced DAT deficits may provide a mouse model for DAT deficits in OCD.
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Affiliation(s)
- Nancy S Woehrle
- Department of Psychology, Wittenberg University, Springfield, OH 45504, USA
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23
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Di Poi C, Darmaillacq AS, Dickel L, Boulouard M, Bellanger C. Effects of perinatal exposure to waterborne fluoxetine on memory processing in the cuttlefish Sepia officinalis. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 132-133:84-91. [PMID: 23474317 DOI: 10.1016/j.aquatox.2013.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 02/05/2013] [Accepted: 02/09/2013] [Indexed: 05/27/2023]
Abstract
Recent ecotoxicological studies highlight the increasing presence of pharmaceuticals discharged in the aquatic environment. Amongst them is the antidepressant fluoxetine (FLX), a selective serotonin reuptake inhibitor, primarily indicated for treatment of depression. The effect of chronic exposure to FLX on memory processing in 1-month-old cuttlefish Sepia officinalis was evaluated. Three groups of new-borns were reared in different conditions: one control group (no FLX) and two groups exposed to environmental concentrations of FLX (1 and 100ng/L) from 15 days pre-hatching to 1 month post-hatching. Acquisition and retention performances were assessed using the 'prawn-in-the-tube' procedure. Perinatal exposure to fluoxetine led to significant changes in memory processing of the animals. The lowest observed effect concentration of this antidepressant on learning and retention was 1ng/L which is under the range of environmental contamination. Cuttlefish exposed at low FLX concentration had impaired acquisition capabilities and animals exposed at high FLX concentration displayed a deficit of memory retention compared to the control group that had nonimpaired initial acquisition and retention performances. The results subsequently suggested that FLX-induced changes in cognitive capacities could potentially lead to inappropriate predatory behaviors in the natural environment. The study provides the basis for future studies on how pharmaceutical contaminants disrupt cognition in ecologically and economically relevant marine invertebrates.
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Affiliation(s)
- Carole Di Poi
- Université de Caen Basse-Normandie, Groupe Mémoire et Plasticité comportementale, EA 4259, 14032 Caen cedex, France
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24
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Saenz del Burgo L, Cortés R, Mengod G, Montaña M, García del Caño G, Sallés J. Chronic effects of corticosterone on GIRK1-3 subunits and 5-HT1A receptor expression in rat brain and their reversal by concurrent fluoxetine treatment. Eur Neuropsychopharmacol 2013; 23:229-39. [PMID: 22591911 DOI: 10.1016/j.euroneuro.2012.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 03/09/2012] [Accepted: 04/14/2012] [Indexed: 11/17/2022]
Abstract
Dysregulation of the serotonergic system and abnormalities of the hypothalamic-pituitary-adrenal axis have been demonstrated in major depression. Animal studies indicate that 5-HT1A receptor expression may be reduced by long-term administration of corticosterone. However, similar studies on the regulation of GIRK channels, one of the most important effectors of the neuronal 5-HT1A receptor, are limited. In order to address these issues, slow-release corticosterone pellets were implanted subcutaneously to adrenal intact male rats (200mg pellets, 35 days release). Starting on day 15, animals were treated for 21 days with fluoxetine (5mg/kg/day, i.p.), or vehicle. Using in situ hybridization histochemistry and receptor autoradiography, we found that chronic corticosterone treatment was accompanied by a significant decrease on the mRNAs coding for mineralocorticoid receptors in hippocampal areas. Under these conditions, 5-HT1A receptor mRNA expression decreased in dorsal raphe nucleus and dentate gyrus. However, 5-HT1A receptor levels, as measured by [(3)H]-8-OH-DPAT binding, diminished significantly only in dentate gyrus. It is noteworthy that chronic treatment with fluoxetine reversed the alterations on 5-HT1A receptor mRNA levels only in dorsal raphe. Finally, chronic corticosterone treatment produced an increase on the mRNA coding for the GIRK2 subunit in several hypothalamic and thalamic areas, which was reversed by fluoxetine. Measurements of cell density and volume of the granular layer of the dentate gyrus did not reveal significant changes after corticosterone or corticosterone plus fluoxetine treatments. These data are relevant for a better understanding of the differential regulation of pre- and postsynaptic 5-HT1A receptors by corticosterone flattened rhythm.
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MESH Headings
- Animals
- Autoradiography
- Corticosterone/pharmacology
- Dentate Gyrus/drug effects
- Dentate Gyrus/metabolism
- Depressive Disorder, Major/metabolism
- Fluoxetine/pharmacology
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/drug effects
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/genetics
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/metabolism
- Gene Expression/drug effects
- Gene Expression Profiling
- Hippocampus/drug effects
- Hippocampus/metabolism
- Hypothalamo-Hypophyseal System/metabolism
- Male
- Pituitary-Adrenal System/metabolism
- Raphe Nuclei/drug effects
- Raphe Nuclei/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/genetics
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Glucocorticoid/drug effects
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Receptors, Mineralocorticoid/drug effects
- Receptors, Mineralocorticoid/genetics
- Receptors, Mineralocorticoid/metabolism
- Selective Serotonin Reuptake Inhibitors/pharmacology
- Thalamus/drug effects
- Thalamus/metabolism
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Affiliation(s)
- Laura Saenz del Burgo
- Department of Pharmacology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
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25
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Artigas F. Serotonin receptors involved in antidepressant effects. Pharmacol Ther 2013; 137:119-31. [DOI: 10.1016/j.pharmthera.2012.09.006] [Citation(s) in RCA: 184] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 09/14/2012] [Indexed: 12/19/2022]
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Descarries L, Riad M. Effects of the antidepressant fluoxetine on the subcellular localization of 5-HT1A receptors and SERT. Philos Trans R Soc Lond B Biol Sci 2012; 367:2416-25. [PMID: 22826342 DOI: 10.1098/rstb.2011.0361] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Serotonin (5-HT) 5-HT(1A) autoreceptors (5-HT(1A)autoR) and the plasmalemmal 5-HT transporter (SERT) are key elements in the regulation of central 5-HT function and its responsiveness to antidepressant drugs. Previous immuno-electron microscopic studies in rats have demonstrated an internalization of 5-HT(1A)autoR upon acute administration of the selective agonist 8-OH-DPAT or the selective serotonin reuptake inhibitor antidepressant fluoxetine. Interestingly, it was subsequently shown in cats as well as in humans that this internalization is detectable by positron emission tomography (PET) imaging with the 5-HT(1A) radioligand [(18)F]MPPF. Further immunocytochemical studies also revealed that, after chronic fluoxetine treatment, the 5-HT(1A)autoR, although present in normal density on the plasma membrane of 5-HT cell bodies and dendrites, do not internalize when challenged with 8-OH-DPAT. Resensitization requires several weeks after discontinuation of the chronic fluoxetine treatment. In contrast, the SERT internalizes in both the cell bodies and axon terminals of 5-HT neurons after chronic but not acute fluoxetine treatment. Moreover, the total amount of SERT immunoreactivity is then reduced, suggesting that SERT is not only internalized, but also degraded in the course of the treatment. Ongoing and future investigations prompted by these finding are briefly outlined by way of conclusion.
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Affiliation(s)
- Laurent Descarries
- Departments of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, , Montreal, Quebec, Canada H3C 3J7.
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27
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Lanzenberger R, Kranz GS, Haeusler D, Akimova E, Savli M, Hahn A, Mitterhauser M, Spindelegger C, Philippe C, Fink M, Wadsak W, Karanikas G, Kasper S. Prediction of SSRI treatment response in major depression based on serotonin transporter interplay between median raphe nucleus and projection areas. Neuroimage 2012; 63:874-81. [PMID: 22828162 DOI: 10.1016/j.neuroimage.2012.07.023] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 07/11/2012] [Accepted: 07/13/2012] [Indexed: 01/01/2023] Open
Abstract
Recent mathematical models suggest restored serotonergic burst-firing to underlie the antidepressant effect of selective serotonin reuptake inhibitors (SSRI), resulting from down-regulated serotonin transporters (SERT) in terminal regions. This mechanism possibly depends on the interregional balance between SERTs in the raphe nuclei and in terminal regions before treatment. To evaluate these hypotheses on a systems level in humans in vivo, we investigated SERT availability and occupancy longitudinally in patients with major depressive disorder using positron emission tomography (PET) and the radioligand [11C]DASB. Measurements were performed before and after a single oral dose, as well as after three weeks (mean 24.73±3.3 days) of continuous oral treatment with either escitalopram (10 mg/day) or citalopram (20 mg/day). Data were analyzed using voxel-wise linear regression and ANOVA to evaluate SERT binding, occupancy and binding ratios (SERT binding of the entire brain compared to SERT binding in the dorsal and median raphe nuclei) in relation to treatment outcome. Regression analysis revealed that treatment response was predicted by pre-treatment SERT binding ratios, i.e., SERT binding in key regions of depression including bilateral habenula, amygdala-hippocampus complex and subgenual cingulate cortex in relation to SERT binding in the median but not dorsal raphe nucleus (p<0.05 FDR-corrected). Similar results were observed in the direct comparison of responders and non-responders. Our data provide a first proof-of-concept for recent modeling studies and further underlie the importance of the habenula and subgenual cingulate cortex in the etiology of and recovery from major depression. These findings may indicate a promising molecular predictor of treatment response and stimulate new treatment approaches based on regional differences in SERT binding.
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Affiliation(s)
- Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria
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28
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Richtand NM, Ahlbrand R, Horn P, Tambyraja R, Grainger M, Bronson SL, McNamara RK. Fluoxetine and aripiprazole treatment following prenatal immune activation exert longstanding effects on rat locomotor response. Physiol Behav 2012; 106:171-7. [PMID: 22342193 DOI: 10.1016/j.physbeh.2012.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 01/23/2012] [Accepted: 02/01/2012] [Indexed: 12/22/2022]
Abstract
AIM Studies characterizing treatment interventions in a naturalistic setting suggest that antidepressant and antipsychotic medications may be equally effective in improving clinical outcome in individuals at high risk for first-episode psychosis. Of interest, both beneficial as well as potentially adverse effects have been observed following fluoxetine treatment in a mouse prenatal immune activation model of relevance to psychosis prevention. We sought to extend those findings by examining the effects of fluoxetine, as well as the antipsychotic medication aripiprazole, in a rat prenatal immune activation model. METHODS Pregnant Sprague-Dawley rats were injected with poly I:C or saline on gestational day 14. Offspring of poly I:C and saline-treated dams received fluoxetine (10.0 mg/kg/d), aripiprazole (0.66 mg/kg/d), or vehicle from postnatal days 35 to 70. Locomotor responses to novelty, saline injection, and amphetamine (1 and 5 mg/kg) were determined at three months, i.e., 21 days following drug discontinuation. RESULTS Both fluoxetine and aripiprazole had beneficial effects on behavioral response to amphetamine (1 mg/kg) at 3 months, ameliorating the impact of prenatal immune activation on offspring of poly I:C-treated dams. Significantly, both drugs also exerted effects in offspring of control (saline-treated) dams on locomotor response to injection. CONCLUSIONS Fluoxetine and aripiprazole pretreatment of poly I:C offspring from postnatal days 35 to 70 stabilized response to amphetamine exposure persisting through 3 months of age, similar to earlier findings in mice that fluoxetine treatment following prenatal immune activation prevented altered locomotor response to amphetamine. The current data also confirm earlier findings of potential adverse behavioral effects in offspring of control dams following treatment with fluoxetine and antipsychotic medications, highlighting the potential for both therapeutic as well as safety concerns with exposure to preventive pharmacological treatments over the course of adolescent development. Further study is needed to determine clinical and epidemiological consequences of these pre-clinical findings.
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Affiliation(s)
- Neil M Richtand
- Cincinnati Veterans Affairs Medical Center, Psychiatry Service (V116A), 3200 Vine Street, Cincinnati, Ohio 45220, United States.
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29
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Characterization of 5-HT1A/1B−/− mice: An animal model sensitive to anxiolytic treatments. Neuropharmacology 2011; 61:478-88. [DOI: 10.1016/j.neuropharm.2011.02.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 02/07/2011] [Accepted: 02/09/2011] [Indexed: 11/24/2022]
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30
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Vidal R, Valdizan EM, Vilaró MT, Pazos A, Castro E. Reduced signal transduction by 5-HT4 receptors after long-term venlafaxine treatment in rats. Br J Pharmacol 2011; 161:695-706. [PMID: 20880406 DOI: 10.1111/j.1476-5381.2010.00903.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE The 5-HT(4) receptor may be a target for antidepressant drugs. Here we have examined the effects of the dual antidepressant, venlafaxine, on 5-HT(4) receptor-mediated signalling events. EXPERIMENTAL APPROACH The effects of 21 days treatment (p.o.) with high (40 mg·kg(-1)) and low (10 mg·kg(-1)) doses of venlafaxine, were evaluated at different levels of 5-HT(4) receptor-mediated neurotransmission by using in situ hybridization, receptor autoradiography, adenylate cyclase assays and electrophysiological recordings in rat brain. The selective noradrenaline reuptake inhibitor, reboxetine (10 mg·kg(-1), 21 days) was also evaluated on 5-HT(4) receptor density. KEY RESULTS Treatment with a high dose (40 mg·kg(-1)) of venlafaxine did not alter 5-HT(4) mRNA expression, but decreased the density of 5-HT(4) receptors in caudate-putamen (% reduction = 26 ± 6), hippocampus (% reduction = 39 ± 7 and 39 ± 8 for CA1 and CA3 respectively) and substantia nigra (% reduction = 49 ± 5). Zacopride-stimulated adenylate cyclase activation was unaltered following low-dose treatment (10 mg·kg(-1)) while it was attenuated in rats treated with 40 mg·kg(-1) of venlafaxine (% reduction = 51 ± 2). Furthermore, the amplitude of population spike in pyramidal cells of CA1 of hippocampus induced by zacopride was significantly attenuated in rats receiving either dose of venlafaxine. Chronic reboxetine did not modify 5-HT(4) receptor density. CONCLUSIONS AND IMPLICATIONS Our data indicate a functional desensitization of 5-HT(4) receptors after chronic venlafaxine, similar to that observed after treatment with the classical selective inhibitors of 5-HT reuptake.
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Affiliation(s)
- R Vidal
- Instituto de Biomedicina y Biotecnología (IBBTEC) (UC-CSIC-IDICAN), Santander, Cantabria, Spain
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31
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Rozeske RR, Greenwood BN, Fleshner M, Watkins LR, Maier SF. Voluntary wheel running produces resistance to inescapable stress-induced potentiation of morphine conditioned place preference. Behav Brain Res 2011; 219:378-81. [PMID: 21262267 DOI: 10.1016/j.bbr.2011.01.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 01/10/2011] [Accepted: 01/13/2011] [Indexed: 12/25/2022]
Abstract
In rodents, exposure to acute inescapable, but not escapable, stress potentiates morphine conditioned place preference (CPP), an effect that is dependent upon hyperactivation of serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN). Six weeks of voluntary wheel running constrains activation of DRN 5-HT neurons during exposure to inescapable stress. Six weeks of voluntary wheel running before inescapable stress blocked stress-induced potentiation of morphine CPP.
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Affiliation(s)
- Robert R Rozeske
- University of Colorado-Boulder, Department of Psychology and Neuroscience, Muenzinger Building, UCB 345, Boulder, CO 80309, USA.
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32
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Facilitation of 5-HT1A-mediated neurotransmission in dorsal periaqueductal grey matter accounts for the panicolytic-like effect of chronic fluoxetine. Int J Neuropsychopharmacol 2010; 13:1079-88. [PMID: 19941697 DOI: 10.1017/s146114570999099x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chronic administration of antidepressants such as fluoxetine and imipramine increases the responsiveness of 5-HT(1A) receptors in dorsal periaqueductal grey matter (DPAG), a midbrain area consistently implicated in the pathogenesis of panic disorder. This effect has been related to the clinically relevant anti-panic action of these drugs. In this study we determined whether long-term administration of fluoxetine also affects 5-HT efflux in DPAG. As a comparison, the effect of chronic treatment with the anxiolytic 5-HT(1A) receptor agonist buspirone on DPAG 5-HT levels was assessed. We also investigated whether the inhibitory effect of chronic fluoxetine on escape behaviour in the rat elevated T-maze, considered as a panicolytic-like effect, is counteracted by intra-DPAG injection of the 5-HT(1A) receptor antagonist WAY 100635. Male Wistar rats were treated (1 or 21 d, i.p.) with fluoxetine, buspirone or vehicle, once daily. After treatment, 5-HT in DPAG was measured by in-vivo microdialysis coupled to HPLC. In another study, rats treated (21 d, i.p.) with either fluoxetine or vehicle also received intra-DPAG injection of WAY 100635 or saline 10 min before being tested in the elevated T-maze. Chronic, but not acute, administration of fluoxetine significantly raised extracellular levels of 5-HT in DPAG. Long-term treatment with buspirone was ineffective. In the elevated T-maze, intra-DPAG injection of WAY 100635 fully blocked the anti-escape effect of chronic administration of fluoxetine. Therefore, chronic fluoxetine facilitates 5-HT(1A)-mediated neurotransmission within DPAG and this effect accounts for the panicolytic-like effect of this antidepressant in the elevated T-maze.
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33
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Lifschytz T, Goltser-Dubner T, Landshut G, Lerer B. Effect of triiodothyronine on 5-HT1A and 5-HT1B receptor expression in rat forebrain and on latency to feed in the novelty suppressed feeding test. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:632-8. [PMID: 20206658 DOI: 10.1016/j.pnpbp.2010.02.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 02/21/2010] [Accepted: 02/27/2010] [Indexed: 11/15/2022]
Abstract
Thyroid hormones, particularly triiodothyronine (T3), have long been used for the treatment of depression, most frequently to enhance the therapeutic activity of other antidepressants. The purpose of this study was to evaluate possible underlying mechanisms for the antidepressant activity of T3. The effects of T3 20 microg/kg/d S.C. and fluoxetine 5mg/kg/d I.P. given alone or in combination for 7 days on the transcription rates of inhibitory serotonergic receptors (5-HT1A and 5-HT1B) were studied in different brain areas of male Sabra rats using real-time PCR. Significant effects of fluoxetine were found on the expression of 5-HT1B receptors in the frontal cortex and of T3 on the expression of 5-HT1A receptors in the amygdala and hippocampus and 5-HT1B receptors in the frontal and entorhinal cortices, the expression being reduced in all cases. An effect of the combination of T3 plus fluoxetine to reduce transcription was observed for 5-HT1A receptors, in the amygdala and dentate gyrus and for 5-HT1B receptors in the entorhinal cortex and anterior raphe nucleus. In the second experiment, the novelty suppressed feeding test (NFST) was used to examine the effects of fluoxetine 5mg/kg/d I.P. and T3 20 or 50 microg/kg/d, alone or in combination for 12 days, on latency to feed. Only the combinations of T3 (20 or 50 microg/kg/d) and fluoxetine (5mg/kg/d) yielded significant behavioral effects in this test. The results of our studies suggest that the mechanism underlying the antidepressant effect of T3 may involve a reduction in 5-HT1A and 5-HT1B receptor transcription rates.
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Affiliation(s)
- Tzuri Lifschytz
- Biological Psychiatry Laboratory, Department of Psychiatry, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
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Dawson LA, Watson JM. Vilazodone: a 5-HT1A receptor agonist/serotonin transporter inhibitor for the treatment of affective disorders. CNS Neurosci Ther 2010; 15:107-17. [PMID: 19499624 DOI: 10.1111/j.1755-5949.2008.00067.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Vilazodone (EMD 68843; 5-{4-[4-(5-cyano-3-indolyl)-butyl]-1-piperazinyl}-benzofuran-2-carboxamide hydrochloride) is a combined serotonin specific reuptake inhibitor (SSRI) and 5-HT1A receptor partial agonist currently under clinical evaluation for the treatment of major depression. This molecule was designed based on the premise that negative feedback circuitry, mediated via 5-HT1 receptors, limits the acute SSRI-induced enhancements in serotonergic neurotransmission. If the hypothesis is correct, combination of SSRI with 5-HT1A partial agonism should temporally enhance the neuroplastic adaptation and subsequently hasten therapeutic efficacy compared to current treatments. Preclinical in vitro evaluation has confirmed vilazodone's primary pharmacological profile both in clonal and native systems, that is, serotonin reuptake blockade and 5-HT1A partial agonism. However, in vivo and in contrast to combination of 8-OH-DPAT and paroxetine, vilazodone selectively enhanced serotonergic output in the prefrontal cortex of rats. Behavioral evaluations, in the ultrasonic vocalization model of anxiety in rats, demonstrated anxiolytic efficacy. In the forced swim test (a putative model of depression), vilazodone also showed efficacy but at a single dose only. In man, vilazodone abolished REM sleep and demonstrated clinical antidepressant efficacy equivalent to an SSRI. Ongoing clinical evaluations will hopefully reveal whether the founding hypothesis was valid and if vilazodone will produce a more rapid onset of antidepressant efficacy.
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Affiliation(s)
- Lee A Dawson
- Neurosciences Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, Essex, UK
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35
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Abstract
OBJECTIVES Desensitization of serotonin 1A (HTR1A) and 1B (HTR1B) autoreceptors has been proposed to be involved in the delayed onset of response to selective serotonin reuptake inhibitors (SSRIs). Variations in gene expression in these genes may thus affect SSRI response. METHODS Here, we test this hypothesis in two samples from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D), and show evidence for involvement of several genetic variants alone and in interaction. Initially, three functional single nucleotide polymorphisms (SNPs) in the HTR1B gene and in the HTR1A gene were analyzed in 153 depressed patients treated with citalopram. The 16-item Quick Inventory of Depressive Symptomatology Clinician scores were evaluated over time with respect to genetic variation. RESULTS Individuals homozygous for the -1019 G allele (rs6295) in HTR1A showed the higher baseline 16-item Quick Inventory of Depressive Symptomatology Clinician scores (P=0.033), and by 12 weeks had a significantly lower response rate (P=0.005). HTR1B haplotypes were estimated according to the previously reported in-vitro expression levels. Individuals who were homozygous for the high-expression haplotype showed significantly slower response to citalopram (P=0.034). We then analyzed more SNPs in the extended overall STAR*D sample. Although we could not directly test the same functional SNPs, we found that homozygotes for the G allele at rs1364043 in HTR1A (P=0.045) and the C allele of rs6298 in HTR1B showed better response to citalopram over time (P=0.022). Test for interaction between rs6298 in HTR1B and rs1364043 in HTR1A was significant (overall P=0.032). CONCLUSION Our data suggest that an enhanced capacity of HTR1B or HTR1A transcriptional activity may impair desensitization of the autoreceptors during SSRI treatment.
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Honig G, Jongsma ME, van der Hart MCG, Tecott LH. Chronic citalopram administration causes a sustained suppression of serotonin synthesis in the mouse forebrain. PLoS One 2009; 4:e6797. [PMID: 19710918 PMCID: PMC2728775 DOI: 10.1371/journal.pone.0006797] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 08/04/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Serotonin (5-HT) is a neurotransmitter with important roles in the regulation of neurobehavioral processes, particularly those regulating affect in humans. Drugs that potentiate serotonergic neurotransmission by selectively inhibiting the reuptake of serotonin (SSRIs) are widely used for the treatment of psychiatric disorders. Although the regulation of serotonin synthesis may be an factor in SSRI efficacy, the effect of chronic SSRI administration on 5-HT synthesis is not well understood. Here, we describe effects of chronic administration of the SSRI citalopram (CIT) on 5-HT synthesis and content in the mouse forebrain. METHODOLOGY/PRINCIPAL FINDINGS Citalopram was administered continuously to adult male C57BL/6J mice via osmotic minipump for 2 days, 14 days or 28 days. Plasma citalopram levels were found to be within the clinical range. 5-HT synthesis was assessed using the decarboxylase inhibition method. Citalopram administration caused a suppression of 5-HT synthesis at all time points. CIT treatment also caused a reduction in forebrain 5-HIAA content. Following chronic CIT treatment, forebrain 5-HT stores were more sensitive to the depleting effects of acute decarboxylase inhibition. CONCLUSIONS/SIGNIFICANCE Taken together, these results demonstrate that chronic citalopram administration causes a sustained suppression of serotonin synthesis in the mouse forebrain. Furthermore, our results indicate that chronic 5-HT reuptake inhibition renders 5-HT brain stores more sensitive to alterations in serotonin synthesis. These results suggest that the regulation of 5-HT synthesis warrants consideration in efforts to develop novel antidepressant strategies.
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Affiliation(s)
- Gerard Honig
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, CA, USA.
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37
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Beyer CE, Lin Q, Platt B, Malberg J, Hornby G, Sullivan KM, Smith DL, Lock T, Mitchell PJ, Hatzenbuhler NT, Evrard DA, Harrison BL, Magolda R, Pangalos MN, Schechter LE, Rosenzweig-Lipson S, Andree TH. Preclinical characterization of WAY-211612: a dual 5-HT uptake inhibitor and 5-HT (1A) receptor antagonist and potential novel antidepressant. Br J Pharmacol 2009; 157:307-19. [PMID: 19338583 DOI: 10.1111/j.1476-5381.2009.00146.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE As a combination of 5-HT selective reuptake inhibitor (SSRI) with 5-HT(1A) receptor antagonism may yield a rapidly acting antidepressant, WAY-211612, a compound with both SSRI and 5-HT(1A) receptor antagonist activities, was evaluated in preclinical models. EXPERIMENTAL APPROACH Occupancy studies confirmed the mechanism of action of WAY-211612, while its in vivo profile was characterized in microdialysis and behavioural models. KEY RESULTS WAY-211612 inhibited 5-HT reuptake (K(i) = 1.5 nmol.L(-1); K(B) = 17.7 nmol.L(-1)) and exhibited full 5-HT(1A) receptor antagonist activity (K(i) = 1.2 nmol.L(-1); K(B) = 6.3 nmol.L(-1); I(max) 100% in adenyl cyclase assays; K(B) = 19.8 nmol.L(-1); I(max) 100% in GTPgammaS). WAY-211612 (3 and 30 mg.kg(-1), po) occupied 5-HT reuptake sites in rat prefrontal cortex (56.6% and 73.6% respectively) and hippocampus (52.2% and 78.5%), and 5-HT(1A) receptors in the prefrontal cortex (6.7% and 44.7%), hippocampus (8.3% and 48.6%) and dorsal raphe (15% and 83%). Acute or chronic treatment with WAY-211612 (3-30 mg.kg(-1), po) raised levels of cortical 5-HT approximately twofold, as also observed with a combination of an SSRI (fluoxetine; 30 mg.kg(-1), s.c.) and a 5-HT(1A) antagonist (WAY-100635; 0.3 mg.kg(-1), s.c). WAY-211612 (3.3-30 mg.kg(-1), s.c.) decreased aggressive behaviour in the resident-intruder model, while increasing the number of punished crossings (3-30 mg.kg(-1), i.p. and 10-56 mg.kg(-1), po) in the mouse four-plate model and decreased adjunctive drinking behaviour (56 mg.kg(-1), i.p.) in the rat scheduled-induced polydipsia model. CONCLUSIONS AND IMPLICATIONS These findings suggest that WAY-211612 may represent a novel antidepressant.
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Affiliation(s)
- C E Beyer
- Discovery Neuroscience, Wyeth Research, Princeton, NJ 08543-8000, USA.
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Moulin-Sallanon M, Charnay Y, Ginovart N, Perret P, Lanfumey L, Hamon M, Hen R, Fagret D, Ibáñez V, Millet P. Acute and chronic effects of citalopram on 5-HT1A receptor-labeling by [18F]MPPF and -coupling to receptors-G proteins. Synapse 2009; 63:106-16. [PMID: 19016488 DOI: 10.1002/syn.20588] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Selective serotonin reuptake inhibitors take several weeks to produce their maximal therapeutic antidepressant effect. This delay has been attributed to the gradual desensitization of somatodendritic serotonin 5-HT(1A) autoreceptors. We evaluated adaptive changes of 5-HT(1A) receptors after acute and chronic citalopram challenges in rat. Small animal positron emission tomography trial and quantitative ex vivo autoradiography studies using [(18)F]MPPF were employed, as well as in vitro 8-OH-DPAT-stimulated [(35)S]-GTPgammaS binding assay. Additionally, 5-HT(1A) receptor knock-out mice were used to assess the specificity of [(18)F]MPPF. Acute treatment with citalopram did not alter [(18)F]MPPF binding in dorsal raphe nucleus (DR), frontal cortex, or hippocampus. The absence of [(18)F]MPPF binding in the brain of 5-HT(1A) knock-out mice demonstrates the specificity of MPPF for 5-HT(1A) receptor brain imaging, but the high affinity of [(18)F]MPPF compared to 5-HT suggests that it would only be displaced by dramatic increases in extracellular 5-HT. Chronic citalopram did not modify 5-HT(1A) receptor density in any of the brain regions studied. In addition, this treatment did not modify 8-OH-DPAT-stimulated [(35)S]-GTPgammaS binding in DR, although a significant increase was observed in frontal cortex and hippocampus. [(18)F]MPPF appears to be an efficient radioligand to quantify specifically 5-HT(1A) receptor density in brain imaging. The delayed therapeutic efficacy of citalopram did not appear to be linked to either a downregulation of 5-HT(1A) receptors or to a 5-HT(1A) receptor-G protein decoupling process in serotonergic neurons, but to increased functional sensitivity of postsynaptic 5-HT(1A) receptors.
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Savitz J, Lucki I, Drevets WC. 5-HT(1A) receptor function in major depressive disorder. Prog Neurobiol 2009; 88:17-31. [PMID: 19428959 DOI: 10.1016/j.pneurobio.2009.01.009] [Citation(s) in RCA: 406] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 12/22/2008] [Accepted: 01/29/2009] [Indexed: 10/21/2022]
Abstract
Dysfunction of the serotonin 1A receptor (5-HT(1A)) may play a role in the genesis of major depressive disorder (MDD). Here we review the pharmacological, post-mortem, positron emission tomography (PET), and genetic evidence in support of this statement. We also touch briefly on two MDD-associated phenotypes, cognitive impairment and somatic pain. The results of pharmacological challenge studies with 5-HT(1A) receptor agonists are indicative of blunted endocrine responses in depressed patients. Lithium, valproate, selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), and other treatment, such as electroconvulsive shock therapy (ECT), all increase post-synaptic 5-HT(1A) receptor signaling through either direct or indirect effects. Reduced somatodendritic and postsynaptic 5-HT(1A) receptor numbers or affinity have been reported in some post-mortem studies of suicide victims, a result consistent with well-replicated PET analyses demonstrating reduced 5-HT(1A) receptor binding potential in diverse regions such as the dorsal raphe, medial prefrontal cortex (mPFC), amygdala and hippocampus. 5-HT(1A) receptor knockout (KO) mice display increased anxiety-related behavior, which, unlike in their wild-type counterparts, cannot be rescued with antidepressant drug (AD) treatment. In humans, the G allele of a single nucleotide polymorphism (SNP) in the 5-HT(1A) receptor gene (HTR1A; rs6295), which abrogates a transcription factor binding site for deformed epidermal autoregulatory factor-1 (Deaf-1) and Hes5, has been reported to be over-represented in MDD cases. Conversely, the C allele has been associated with better response to AD drugs. We raise the possibility that 5-HT(1A) receptor dysfunction represents one potential mechanism underpinning MDD and other stress-related disorders.
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Affiliation(s)
- Jonathan Savitz
- Section on Neuroimaging in Mood and Anxiety Disorders, Mood and Anxiety Disorders Program, NIH/NIMH, Bethesda, MD 20892, United States.
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Muraki I, Inoue T, Hashimoto S, Izumi T, Koyama T. Effect of different challenge doses after repeated citalopram treatment on extracellular serotonin level in the medial prefrontal cortex: in vivo microdialysis study. Psychiatry Clin Neurosci 2008; 62:568-74. [PMID: 18950377 DOI: 10.1111/j.1440-1819.2008.01851.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS In order to elucidate the relevance between the delayed onset of clinical efficacy of selective serotonin re-uptake inhibitors (SSRI) and extracellular 5-HT levels in the medial prefrontal cortex, the present study compared the ability of low-dose (3 mg/kg) and high-dose (30 mg/kg) citalopram to increase extracellular 5-HT levels in the medial prefrontal cortex following repeated citalopram treatment using in vivo microdialysis. METHODS An SSRI, citalopram, was given 10 mg/kg, s.c. twice daily for 6 days and once on the seventh day in rats. On the eighth day, rats received a single injection of citalopram (3 or 30 mg/kg s.c.), and extracellular 5-HT levels were assessed in the medial prefrontal cortex of rats using in vivo brain microdialysis. RESULTS There was no significant difference in basal extracellular 5-HT levels between the repeated citalopram group and the repeated saline group. The low-challenge dose of citalopram (3 mg/kg) produced significantly greater increases (170-200% at each time point) in the repeated citalopram group than in the repeated saline group (150%). The high-challenge dose of citalopram (30 mg/kg), however, increased extracellular 5-HT levels by 200-250% of basal levels in the repeated citalopram group, which was similar to the increases in the repeated saline group. CONCLUSIONS Repeated SSRI treatment enhances the effect of low-dose SSRI on extracellular 5-HT levels but not that of high-dose SSRI.
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Affiliation(s)
- Ihoko Muraki
- Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Castro E, Díaz A, Rodriguez-Gaztelumendi A, Del Olmo E, Pazos A. WAY100635 prevents the changes induced by fluoxetine upon the 5-HT1A receptor functionality. Neuropharmacology 2008; 55:1391-6. [PMID: 18809415 DOI: 10.1016/j.neuropharm.2008.08.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 08/28/2008] [Accepted: 08/28/2008] [Indexed: 11/19/2022]
Abstract
5-HT1A receptor-mediated signalling in rat brain was evaluated after chronic administration (14 days; s.c.) of the selective serotonin reuptake inhibitor (SRRI) fluoxetine (10 mg/kg/day) alone, or in combination with the 5-HT1A receptor antagonist WAY100635 (0.1 mg/kg/day). The density of 5-HT1A binding sites was unchanged following fluoxetine, WAY100635, or the combination of fluoxetine and WAY100635. However, the net stimulation of [35S]GTPgammaS binding induced by the 5-HT1A agonist 8-OH-DPAT was significantly attenuated in dorsal raphe nucleus (DRN), but not in hippocampus, after chronic fluoxetine. Moreover, depending of the area analysed, the basal binding of [35S]GTPgammaS was differentially affected by this treatment: increased in DRN and decreased in hippocampal dentate gyrus. Interestingly, the changes in [35S]GTPgammaS basal binding and on 5-HT1A receptors functionality were prevented by the concomitant administration of WAY100635. The inhibition of dorsal raphe firing by 8-OH-DPAT was also attenuated in fluoxetine-treated rats (ED50 = 2.12 +/- 0.32 microg/kg and 4.34 +/- 0.09 microg/kg, for vehicle and fluoxetine respectively), an effect which was also prevented by the concomitant administration of WAY100635 (ED50 = 2.10 +/- 0.58 microg/kg). Chronic administration of WAY100635 alone did not affect the 5-HT1A receptor-induced stimulation of [35S]GTPgammaS binding, nor the 8-OH-DPAT-induced inhibition of 5-HT neuron firing. These results demonstrate that the concomitant blockade of 5-HT1A receptors when administering fluoxetine prevents those adaptive changes of 5-HT1A receptor function associated with the chronic administration of this antidepressant. These findings could be relevant from the therapeutic point of view, and further support the potential benefit of treatments with a SSRI/5-HT1A receptor antagonist combination.
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Affiliation(s)
- Elena Castro
- Departamento de Fisiología y Farmacología, Universidad de Cantabria, Spain
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Günther L, Liebscher S, Jähkel M, Oehler J. Effects of chronic citalopram treatment on 5-HT1A and 5-HT2A receptors in group- and isolation-housed mice. Eur J Pharmacol 2008; 593:49-61. [PMID: 18657534 DOI: 10.1016/j.ejphar.2008.07.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 06/27/2008] [Accepted: 07/09/2008] [Indexed: 01/01/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRI) are characterized by high clinical effectiveness and good tolerability. A 2-3 week delay in the onset of effects is caused by adaptive mechanisms, probably at the serotonergic (5-HT) receptor level. To analyze this in detail, we measured 5-HT(1A) and 5-HT(2A) receptor bindings in vitro after 3 weeks of citalopram treatment (20 mg/kg i.p. daily) in group-housed as well as isolation-housed mice, reflecting neurobiological aspects seen in psychiatric patients. Isolation housing increased somatodendritic (+52%) and postsynaptic (+30-95%) 5-HT(1A) as well as postsynaptic 5-HT(2A) receptor binding (+25-34%), which confirms previous findings. Chronic citalopram treatment did not induce alterations in raphe 5-HT(1A) autoreceptor binding, independent of housing conditions. Housing-dependent citalopram effects on postsynaptic 5-HT(1A) receptor binding were found with increases in group- (+11-42%) but decreases in isolation-housed (-11 to 35%) mice. Forebrain 5-HT(2A) receptor binding decreased between 11 and 38% after chronic citalopram administration, independent of housing conditions. Citalopram's long-term action comprises alterations at the postsynaptic 5-HT(1A) and 5-HT(2A) receptor binding levels. Housing conditions interact with citalopram effects, especially on 5-HT(1A) receptor binding, and should be more strongly considered in pharmacological studies. In general, SSRI-induced alterations were more pronounced and affected more brain regions in isolates, supporting the concept of a higher responsiveness in "stressed" animals. Isolation-induced receptor binding changes were partly normalized by chronic citalopram treatment, suggesting the isolation housing model for further analyses of SSRI effects, especially at the behavioral level.
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Affiliation(s)
- Lydia Günther
- AG Neurobiologie, Klinik für Psychiatrie, Universitätsklinikum der TU Dresden, Fetscherstrasse 74, Dresden, Germany.
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Rossi DV, Burke TF, McCasland M, Hensler JG. Serotonin-1A receptor function in the dorsal raphe nucleus following chronic administration of the selective serotonin reuptake inhibitor sertraline. J Neurochem 2007; 105:1091-9. [PMID: 18182050 DOI: 10.1111/j.1471-4159.2007.05201.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Serotonin-1A (5-HT(1A) receptors in the dorsal raphe nucleus (DRN) function as somatodendritic autoreceptors, and therefore play a critical role in controlling serotonergic cell firing and serotonergic neurotransmission. We hypothesized that a decrease in the capacity of 5-HT(1A) receptors to activate G proteins was a general mechanism by which 5-HT(1A) receptors in the DRN are desensitized following chronic administration of selective serotonin reuptake inhibitors (SSRIs). Using in vivo microdialysis, we found that the ability of the 5-HT(1A) receptor agonist 8-hydroxydipropylaminotetralin hydrobromide (8-OH-DPAT) (0.025 mg/kg, s.c.) to decrease extracellular 5-HT levels in striatum was attenuated following chronic treatment of rats with the SSRIs sertraline or fluoxetine. This apparent desensitization of somatodendritic 5-HT(1A) autoreceptor function was not accompanied by a decrease in 5-HT(1A) receptor sites in the coupled, high-affinity agonist state as measured by the binding of [3H]8-OH-DPAT. In marked contrast to what was observed following chronic administration of fluoxetine, 5-HT(1A) receptor-stimulated [(35)S]GTPgammaS binding in the DRN was not altered following chronic sertraline treatment. Thus, desensitization of 5-HT(1A) somatodendritic autoreceptor function following chronic sertraline administration appears not to be due to a decrease in the capacity 5-HT(1A) receptors to activate G proteins in the DRN. Our findings suggest that the SSRIs may not be a homogeneous class of antidepressant drug with regard to the mechanism by which the function of somatodendritic 5-HT(1A) autoreceptors is regulated.
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Affiliation(s)
- Dania V Rossi
- Department of Pharmacology, University of Texas Health Science Center-San Antonio, San Antonio, Texas 78229-3900, USA
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Riad M, Rbah L, Verdurand M, Aznavour N, Zimmer L, Descarries L. Unchanged density of 5-HT(1A) autoreceptors on the plasma membrane of nucleus raphe dorsalis neurons in rats chronically treated with fluoxetine. Neuroscience 2007; 151:692-700. [PMID: 18166275 DOI: 10.1016/j.neuroscience.2007.11.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 11/14/2007] [Accepted: 11/19/2007] [Indexed: 11/18/2022]
Abstract
5-HT(1A) autoreceptors regulate the firing of 5-HT neurons and their release of 5-HT. In previous immuno-electron microscopic studies, we have demonstrated an internalization of 5-HT(1A) autoreceptors in the nucleus raphe dorsalis (NRD) of rats, after the acute administration of a single dose of the specific agonist 8-hydroxy-2-(di-n-propylamine)tetralin (8-OH-DPAT) or of the selective 5-HT reuptake inhibitor, fluoxetine. Twenty-four hours after either treatment, the receptors were back in normal density on the plasma membrane of NRD neurons. Here, we examined the subcellular localization of these receptors and the in vivo binding of the 5-HT(1A) radioligand 4,2-(methoxyphenyl)-1-[2-(N-2-pyridinyl)-p-fluorobenzamido]ethylpiperazine labeled with [(18)F]fluorine ([(18)F]MPPF) after chronic fluoxetine treatment (10 mg/kg daily for 3 weeks, by minipump). Unexpectedly, after such a treatment, there were no more differences between treated and control rats in either the density of plasma membrane labeling of NRD dendrites, or in the in vivo binding of [(18)F]MPPF, as measured with beta-microprobes. This was in keeping with earlier reports of an unchanged density of 5-HT(1A) receptor binding sites after chronic fluoxetine treatment, but quite unexpected from the strong electrophysiological and biochemical evidence for a desensitization of 5-HT(1A) autoreceptors under such conditions. Indeed, when the fluoxetine-treated rats were challenged with a single dose of 8-OH-DPAT, there was no internalization of the 5-HT(1A) autoreceptors, at variance with the controls. Interestingly, several laboratories have reported an uncoupling of 5-HT(1A) autoreceptors from their G protein in the NRD of rats chronically treated with fluoxetine. Therefore, the best explanation for our results is that, after repeated internalization and retargeting, functional 5-HT(1A) autoreceptors are replaced by receptors uncoupled from their G protein on the plasma membrane of NRD 5-HT neurons. Thus, the regulatory function of these autoreceptors may depend on a dynamic balance among their production, activation, internalization and recycling to the plasma membrane in inactivated (desensitized) form.
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Affiliation(s)
- M Riad
- Department of Pathology, and Groupe de recherche sur le système nerveux central, Faculty of Medicine, Université de Montréal, CP 6128, Succursale Centre-ville, Montreal, QC, Canada H3C 3J7
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Starr KR, Price GW, Watson JM, Atkinson PJ, Arban R, Melotto S, Dawson LA, Hagan JJ, Upton N, Duxon MS. SB-649915-B, a novel 5-HT1A/B autoreceptor antagonist and serotonin reuptake inhibitor, is anxiolytic and displays fast onset activity in the rat high light social interaction test. Neuropsychopharmacology 2007; 32:2163-72. [PMID: 17356576 DOI: 10.1038/sj.npp.1301341] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Preclinically, the combination of an SSRI and 5-HT autoreceptor antagonist has been shown to reduce the time to onset of anxiolytic activity compared to an SSRI alone. In accordance with this, clinical data suggest the coadministration of an SSRI and (+/-) pindolol can decrease the time to onset of anxiolytic/antidepressant activity. Thus, the dual-acting novel SSRI and 5-HT(1A/B) receptor antagonist, SB-649915-B, has been assessed in acute and chronic preclinical models of anxiolysis. SB-649915-B (0.1-1.0 mg/kg, i.p.) significantly reduced ultrasonic vocalization in male rat pups separated from their mothers (ED(50) of 0.17 mg/kg). In the marmoset human threat test SB-649915-B (3.0 and 10 mg/kg, s.c.) significantly reduced the number of postures with no effect on locomotion. In the rat high light social interaction (SI), SB-649915-B (1.0-7.5 mg/kg, t.i.d.) and paroxetine (3.0 mg/kg, once daily) were orally administered for 4, 7, and 21 days. Ex vivo inhibition of [(3)H]5-HT uptake was also measured following SI. SB-649915-B and paroxetine had no effect on SI after 4 days. In contrast to paroxetine, SB-649915-B (1.0 and 3.0 mg/kg, p.o., t.i.d.) significantly (p<0.05) increased SI time with no effect on locomotion, indicative of an anxiolytic-like profile on day 7. Anxiolysis was maintained after chronic (21 days) administration by which time paroxetine also increased SI significantly. 5-HT uptake was inhibited by SB-649915-B at all time points to a similar magnitude as that seen with paroxetine. In conclusion, SB-649915-B is acutely anxiolytic and reduces the latency to onset of anxiolytic behavior compared to paroxetine in the SI model.
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Affiliation(s)
- Kathryn R Starr
- Schizophrenia and Bipolar Research, Psychiatry Centre of Excellence in Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Essex CM19 5AW, UK
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Unceta N, Barrondo S, Ruiz de Azúa I, Gómez-Caballero A, Goicolea MA, Sallés J, Barrio RJ. Determination of fluoxetine, norfluoxetine and their enantiomers in rat plasma and brain samples by liquid chromatography with fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 852:519-28. [PMID: 17329174 DOI: 10.1016/j.jchromb.2007.02.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 02/01/2007] [Accepted: 02/06/2007] [Indexed: 11/26/2022]
Abstract
Fluoxetine (FLX) and norfluoxetine (NFLX) racemic mixtures were determined by reversed-phase liquid chromatography with fluorescence detection (lambda(exc)=227 nm, lambda(em)=305 nm). The calibration curves prepared from drug-free plasma and brain were linear in the range of 5-1000 ng ml(-1) and 100-40,000 ng g(-1) for doped samples, with detection limits of 3.2 and 2.1 ng ml(-1) in plasma and 31.5 and 26.1 ng g(-1) in brain tissue for FLX and NFLX, respectively. Enantiomer determination was carried out through normal phase HPLC-FD (lambda(exc)=224 nm, lambda(em)=336 nm) after precolumn chiral derivatization with R-1-(1-naphthyl)ethyl isocyanate. Standard curves also prepared in a drug-free matrix were linear for each enantiomer over the range of 2-1000 ng ml(-1) and 20-7000 ng g(-1) with detection limits for the four compounds ranging between 0.2 and 0.5 ng ml(-1) in plasma and between 3.0 and 8.2 ng g(-1) in brain tissue. In both methods the analytes were isolated from the biological matrix by a new solid-phase extraction procedure with recovery in plasma and brain over 90 and 87%, respectively. The repeatability of this extraction procedure was satisfactory within-day and between-day with CV<9.1%. This study also offered the opportunity to obtain an assessment of the potential relationships between the concentration of individual enantiomers of FLX and NFLX in plasma and brain tissue after chronic treatment with racemic FLX at a dose intended to mimic the human plasma concentration of FLX in standard clinical conditions, and therefore should make for more reliable extrapolation of neurochemical findings in other species.
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Affiliation(s)
- Nora Unceta
- Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, Vitoria-Gasteiz, Spain
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Hughes ZA, Starr KR, Scott CM, Newson MJ, Sharp T, Watson JM, Hagan JJ, Dawson LA. Simultaneous blockade of 5-HT1A/B receptors and 5-HT transporters results in acute increases in extracellular 5-HT in both rats and guinea pigs: in vivo characterization of the novel 5-HT1A/B receptor antagonist/5-HT transport inhibitor SB-649915-B. Psychopharmacology (Berl) 2007; 192:121-33. [PMID: 17265079 DOI: 10.1007/s00213-006-0691-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 12/21/2006] [Indexed: 11/26/2022]
Abstract
RATIONALE The delay in onset and treatment resistance of subpopulations of depressed patients to conventional serotonin reuptake inhibitors has lead to new drug development strategies to produce agents with improved antidepressant efficacy. OBJECTIVES We report the in vivo characterization of the novel 5-HT(1A/1B) autoreceptor antagonist/5-HT transporter inhibitor (6-[(1-{2-[(2-methyl-5-quinolinyl)oxy]ethyl}-4-piperidinyl)methyl]-2H-1,4-benzoxazin-3(4H)-one), SB-649915-B. MATERIALS AND METHODS Ex vivo binding was used to ascertain 5-HT(1A) receptor and serotonin transporter occupancy. 8-OH-DPAT-induced hyperlocomotion and SKF-99101-induced elevation of seizure threshold were used as markers of central blockade of 5-HT(1A) and 5-HT(1B) receptors, respectively. In vivo electrophysiology in the rat dorsal raphe and microdialysis in freely moving guinea pigs and rats were used to evaluate the functional outcome of SB-649915-B. RESULTS SB-649915-B (1-10 mg/kg p.o.) produced a dose-related inhibition of 5-HT(1A) receptor radioligand binding and inhibited ex vivo [(3)H]5-HT uptake in both guinea pig and rat cortex. SB-649915-B (0.1-10 mg/kg p.o.) reversed both 8-OH-DPAT-induced hyperlocomotor activity and SKF-99101-induced elevation of seizure threshold in the rat, demonstrating in vivo blockade of both 5-HT(1A) and 5-HT(1B) receptors, respectively. SB-649915-B (0.1-3 mg/kg i.v.) produced no change in raphe 5-HT neuronal cell firing per se but attenuated the inhibitory effect of 8-OH-DPAT. Acute administration of SB-649915-B resulted in increases (approximately two- to threefold) in extracellular 5-HT in the cortex of rats and the dentate gyrus and cortex of guinea pigs. CONCLUSIONS Based on these data, one may speculate that the 5-HT autoreceptor antagonist/5-HT transport inhibitor SB-649915-B will have therapeutic efficacy in the treatment of affective disorders with the potential for a faster onset of action compared to current selective serotonin reuptake inhibitors.
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Affiliation(s)
- Zoë A Hughes
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park (North), Harlow, Essex, CM19 5AW, UK
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Rosenzweig-Lipson S, Beyer CE, Hughes ZA, Khawaja X, Rajarao SJ, Malberg JE, Rahman Z, Ring RH, Schechter LE. Differentiating antidepressants of the future: Efficacy and safety. Pharmacol Ther 2007; 113:134-53. [PMID: 17010443 DOI: 10.1016/j.pharmthera.2006.07.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Accepted: 07/18/2006] [Indexed: 11/17/2022]
Abstract
There have been significant advances in the treatment of depression since the serendipitous discovery that modulating monoaminergic neurotransmission may be a pathological underpinning of the disease. Despite these advances, particularly over the last 15years with the introduction of selective serotonin and/or norepinephrine reuptake inhibitors (SNRI), there still remain multiple unmet clinical needs that would represent substantial improvements to current treatment regimens. In terms of efficacy there have been improvements in the percentage of patients achieving remission but this can still be dramatically improved and, in fact, issues still remain with relapse. Furthermore, advances are still required in terms of improving the onset of efficacy as well as addressing the large proportion of patients who remain treatment resistant. While this is not well understood, collective research in the area suggests the disease is heterogeneous in terms of the multiple parameters related to etiology, pathology and response to pharmacological agents. In addition to efficacy further therapeutic advances will also need to address such issues as cognitive impairment, pain, sexual dysfunction, nausea and emesis, weight gain and potential cardiovascular effects. With these unmet needs in mind, the next generation of antidepressants will need to differentiate themselves from the current array of therapeutics for depression. There are multiple strategies for addressing unmet needs that are currently being investigated. These range from combination monoaminergic approaches to subtype selective agents to novel targets that include mechanisms to modulate neuropeptides and excitatory amino acids (EAA). This review will discuss the many facets of differentiation and potential strategies for the development of novel antidepressants.
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Watson JM, Dawson LA. Characterization of the potent 5-HT(1A/B) receptor antagonist and serotonin reuptake inhibitor SB-649915: preclinical evidence for hastened onset of antidepressant/anxiolytic efficacy. CNS DRUG REVIEWS 2007; 13:206-23. [PMID: 17627673 PMCID: PMC6726354 DOI: 10.1111/j.1527-3458.2007.00012.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
An increase in brain serotonin (5-HT) levels is thought to be a key mechanism of action responsible for generating antidepressant efficacy. It has been proven that selective serotonin reuptake inhibitors are effective antidepressants, but the delay to therapeutic onset of these agents is thought to be due to the time required for 5-HT1A, and possibly 5-HT1B, autoreceptors to desensitize. Therefore, an agent incorporating 5-HT reuptake inhibition coupled with 5-HT1A and/or 5-HT1B autoreceptor antagonism may provide a fast-acting clinical agent. The current studies review the profile of SB-649915 (6-[(1-{2-[(2-methylquinolin-5-yl)oxy]ethyl}piperidin-4-yl)methyl]-2H-1,4-benzoxazin-3(4H)-one), a novel compound with high affinity for human (h) 5-HT1A and 5-HT1B receptors (pKi values of 8.6 and 8.0, respectively) as well as the (h) 5-HT transporter (SERT) (pKi value of 9.3). SB-649915 behaved as an antagonist at both 5-HT1A and 5-HT1B receptors in vitro and in vivo, reversing 5-HT, (+)8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) and SKF99101-induced functional/behavioral responses. Furthermore, it inhibited [3H]5-HT reuptake in rat cortical synaptosomes, in vitro and ex vivo. In electrophysiological studies SB-649915 had no effect on rat dorsal raphe neuronal cell firing per se, but reversed 8-OH-DPAT-induced inhibition of firing both in vitro and in vivo. In addition, in a microdialysis study, it produced an acute increase in extracellular 5-HT in forebrain structures of the rat. Finally, SB-649915 demonstrated acute anxiolytic activity in both rodent and non-human primate and reduced the latency to onset of anxiolytic behavior, compared to paroxetine, in the rat social interaction paradigm. In summary, SB-649915 is a novel, potent 5-HT1A/1B autoreceptor antagonist, and 5-HT reuptake inhibitor. This particular pharmacological profile provides a novel mechanism that could offer fast-acting antidepressant activity.
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Affiliation(s)
- Jeannette M Watson
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Harlow, Essex, UK.
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Parsey RV, Oquendo MA, Ogden RT, Olvet DM, Simpson N, Huang YY, Van Heertum RL, Arango V, Mann JJ. Altered serotonin 1A binding in major depression: a [carbonyl-C-11]WAY100635 positron emission tomography study. Biol Psychiatry 2006; 59:106-13. [PMID: 16154547 DOI: 10.1016/j.biopsych.2005.06.016] [Citation(s) in RCA: 257] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 05/25/2005] [Accepted: 06/10/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Serotonin 1A receptors (5-HT(1A)) are implicated in the pathophysiology of major depressive disorder (MDD) and in the action of selective serotonin reuptake inhibitors (SSRI). SSRI desensitize 5-HT(1A) and down-regulate 5-HT transporters (5-HTT) with the latter persisting for weeks after discontinuation of SSRI. MDD subjects are more likely to be homozygous for the functional 5-HT(1A) G(-1019) allele of the promoter polymorphism and are postulated to have higher 5-HT(1A) than healthy volunteers (controls). We measure 5-HT(1A) in MDD, assess the effects of antidepressant exposure (AE), and examine the role of the C(-1019)G polymorphism. METHODS Genotyped and determined 5-HT(1A) binding potential (BP) by positron emission tomography (PET) using [carbonyl-C-11]-WAY-100635 in 28 medication-free MDD subjects during a current major depressive episode and 43 controls. RESULTS No difference in BP between controls and MDD subjects (p = .235). There was a difference in BP comparing the controls, antidepressant naive (AN) MDD subjects, and subjects with AE across all regions (p = .013). Post hoc testing reveals higher BP in AN compared to controls (p = .008) and to AE (p = .007). The GG genotype is overrepresented in MDD subjects (p = .059), and BP appears higher with the G allele. CONCLUSIONS AN have higher 5-HT(1A) than controls and AE suggesting a model of depression characterized by an over expression of autoinhibitory somatodendritic 5-HT(1A) receptors, perhaps due to the higher expressing G allele, that may result in reduced terminal field 5-HT release. AE appears to have long-term effects on 5-HT(1A).
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MESH Headings
- Adolescent
- Adult
- Antidepressive Agents/therapeutic use
- Carbon Radioisotopes/metabolism
- Depressive Disorder, Major/diagnostic imaging
- Depressive Disorder, Major/drug therapy
- Depressive Disorder, Major/genetics
- Depressive Disorder, Major/metabolism
- Female
- Humans
- Male
- Piperazines/metabolism
- Polymorphism, Genetic
- Positron-Emission Tomography
- Promoter Regions, Genetic/genetics
- Pyridines/metabolism
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/genetics
- Receptor, Serotonin, 5-HT1A/metabolism
- Reference Values
- Serotonin Antagonists/metabolism
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Affiliation(s)
- Ramin V Parsey
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York, USA.
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