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Ozols AB, Wei J, Campbell JM, Hu C, Qiu S, Gallitano AL. Activity of prefrontal cortex serotonin 2A receptor expressing neurons is necessary for the head-twitch response of mice to psychedelic drug DOI in a sex-dependent manner. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.21.595211. [PMID: 38826361 PMCID: PMC11142205 DOI: 10.1101/2024.05.21.595211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Serotonin 2A receptors (5-HT 2A Rs) mediate the effects of psychedelic drugs. 5-HT 2A R agonists, such as (-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI), that produce a psychedelic experience in humans induce a head-twitch response (HTR) behavior in rodents. However, it is unknown whether the activity of 5-HT 2A R expressing neurons is sufficient to produce the HTR in the absence of an agonist, or in which brain region 5-HT 2A Rs control the HTR. Here, we use an optogenetic approach to examine whether activation of 5-HT 2A R expressing neurons in the mouse prefrontal cortex (PFC) is sufficient to induce HTRs alone, or may augment the HTR produced by DOI, and if inhibition of these neurons prevents DOI-induced HTRs in mice. We crossed Htr2a -Cre mice to Cre-dependent optogenetic lines Ai32 (channelrhodopsin) and Ai39 (halorhodopsin) to selectively activate and inhibit (respectively) 5-HT 2A R-expressing neurons in the PFC of adult mice. We found that optogenetic stimulation of PFC 5-HT 2A R expressing neurons in the absence of an agonist does not increase HTRs in mice. In both male and female Ai32 mice that received vehicle, there was no difference in HTRs in mice that expressed Htr2a -Cre compared with control mice, indicating that optogenetic activation of 5-HT 2A R+ cells in the PFC was not sufficient to produce HTRs in the absence of an agonist. In female mice, activation of PFC 5-HT 2A R expressing neurons augmented the HTR produced by DOI. However, this result was not seen in male mice. In contrast, inhibition of 5-HT 2A R expressing neurons in the PFC prevented the increase in HTR produced by DOI in male, but not in female, mice. Together, these findings suggest that activation of 5-HT 2A Rs in the PFC is not sufficient to induce HTRs in the absence of a 5-HT 2A R agonist but is necessary for induction of HTRs by a 5-HT 2A R agonist in a sex-dependent manner.
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2
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Conn K, Milton LK, Huang K, Munguba H, Ruuska J, Lemus MB, Greaves E, Homman-Ludiye J, Oldfield BJ, Foldi CJ. Psilocybin restrains activity-based anorexia in female rats by enhancing cognitive flexibility: contributions from 5-HT1A and 5-HT2A receptor mechanisms. Mol Psychiatry 2024:10.1038/s41380-024-02575-9. [PMID: 38678087 DOI: 10.1038/s41380-024-02575-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/16/2024] [Accepted: 04/19/2024] [Indexed: 04/29/2024]
Abstract
Psilocybin has shown promise for alleviating symptoms of depression and is currently in clinical trials for the treatment of anorexia nervosa (AN), a condition that is characterised by persistent cognitive inflexibility. Considering that enhanced cognitive flexibility after psilocybin treatment is reported to occur in individuals with depression, it is plausible that psilocybin could improve symptoms of AN by breaking down cognitive inflexibility. A mechanistic understanding of the actions of psilocybin is required to tailor the clinical application of psilocybin to individuals most likely to respond with positive outcomes. This can only be achieved using incisive neurobiological approaches in animal models. Here, we use the activity-based anorexia (ABA) rat model and comprehensively assess aspects of reinforcement learning to show that psilocybin (post-acutely) improves body weight maintenance in female rats and facilitates cognitive flexibility, specifically via improved adaptation to the initial reversal of reward contingencies. Further, we reveal the involvement of signalling through the serotonin (5-HT) 1 A and 5-HT2A receptor subtypes in specific aspects of learning, demonstrating that 5-HT1A antagonism negates the cognitive enhancing effects of psilocybin. Moreover, we show that psilocybin elicits a transient increase and decrease in cortical transcription of these receptors (Htr2a and Htr1a, respectively), and a further reduction in the abundance of Htr2a transcripts in rats exposed to the ABA model. Together, these findings support the hypothesis that psilocybin could ameliorate cognitive inflexibility in the context of AN and highlight a need to better understand the therapeutic mechanisms independent of 5-HT2A receptor binding.
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Affiliation(s)
- K Conn
- Monash University, Department of Physiology, 26 Innovation Walk, Clayton, VIC, 3800, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
| | - L K Milton
- Monash University, Department of Physiology, 26 Innovation Walk, Clayton, VIC, 3800, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
| | - K Huang
- Monash University, Department of Physiology, 26 Innovation Walk, Clayton, VIC, 3800, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
| | - H Munguba
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, 10065, USA
| | - J Ruuska
- University of Helsinki, Yliopistonkatu 4, 00100, Helsinki, Finland
| | - M B Lemus
- Monash University, Department of Physiology, 26 Innovation Walk, Clayton, VIC, 3800, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
| | - E Greaves
- Monash University, Department of Physiology, 26 Innovation Walk, Clayton, VIC, 3800, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
| | - J Homman-Ludiye
- Monash Micro Imaging, Monash University, 15 Innovation Walk, Clayton, VIC, 3800, Australia
| | - B J Oldfield
- Monash University, Department of Physiology, 26 Innovation Walk, Clayton, VIC, 3800, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia
| | - C J Foldi
- Monash University, Department of Physiology, 26 Innovation Walk, Clayton, VIC, 3800, Australia.
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, Clayton, VIC, 3800, Australia.
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3
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Chen Z, Yu J, Wang H, Xu P, Fan L, Sun F, Huang S, Zhang P, Huang H, Gu S, Zhang B, Zhou Y, Wan X, Pei G, Xu HE, Cheng J, Wang S. Flexible scaffold-based cheminformatics approach for polypharmacological drug design. Cell 2024; 187:2194-2208.e22. [PMID: 38552625 DOI: 10.1016/j.cell.2024.02.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 02/04/2024] [Accepted: 02/27/2024] [Indexed: 04/28/2024]
Abstract
Effective treatments for complex central nervous system (CNS) disorders require drugs with polypharmacology and multifunctionality, yet designing such drugs remains a challenge. Here, we present a flexible scaffold-based cheminformatics approach (FSCA) for the rational design of polypharmacological drugs. FSCA involves fitting a flexible scaffold to different receptors using different binding poses, as exemplified by IHCH-7179, which adopted a "bending-down" binding pose at 5-HT2AR to act as an antagonist and a "stretching-up" binding pose at 5-HT1AR to function as an agonist. IHCH-7179 demonstrated promising results in alleviating cognitive deficits and psychoactive symptoms in mice by blocking 5-HT2AR for psychoactive symptoms and activating 5-HT1AR to alleviate cognitive deficits. By analyzing aminergic receptor structures, we identified two featured motifs, the "agonist filter" and "conformation shaper," which determine ligand binding pose and predict activity at aminergic receptors. With these motifs, FSCA can be applied to the design of polypharmacological ligands at other receptors.
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Affiliation(s)
- Zhangcheng Chen
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Jing Yu
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Huan Wang
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Peiyu Xu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Luyu Fan
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Fengxiu Sun
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Sijie Huang
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Pei Zhang
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | | | - Shuo Gu
- ComMedX, Beijing 100094, China
| | | | - Yue Zhou
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | | | - Gang Pei
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - H Eric Xu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| | - Jianjun Cheng
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
| | - Sheng Wang
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
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Huang C, van Wijnen AJ, Im HJ. Serotonin Transporter (5-Hydroxytryptamine Transporter, SERT, SLC6A4) and Sodium-dependent Reuptake Inhibitors as Modulators of Pain Behaviors and Analgesic Responses. THE JOURNAL OF PAIN 2024; 25:618-631. [PMID: 37852405 DOI: 10.1016/j.jpain.2023.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 10/20/2023]
Abstract
The serotonin transporter (5-hydroxytryptamine transporter [5-HTT], Serotonin Transporter (SERT), SLC6A4) modulates the activity of serotonin via sodium-dependent reuptake. Given the established importance of serotonin in the control of pain, 5-HTT has received much interest in studies of pain states and as a pharmacological target for serotonin reuptake inhibitors (SRIs). Animal models expressing varying levels of 5-HTT activity show marked differences in pain behaviors and analgesic responses, as well as many serotonin-related physiological effects. In humans, functional nucleotide variations in the SLC6A4 gene, which encodes the serotonin transporter 5-HTT, are associated with certain pathologic pain conditions and differences in responses to pharmacological therapy. These findings collectively reflect the importance of 5-HTT in the intricate physiology and management of pain, as well as the scientific and clinical challenges that need to be considered for the optimization of 5-HTT-related analgesic therapies. PERSPECTIVE: The serotonin transporter 5-HTT/SCL6A4 is sensitive to pharmacological SRIs. Experimental studies on the physiological functions of serotonin, as well as genetic mouse models and clinical phenotype/genotype correlations of nucleotide variation in the human 5-HTT/SCL6A4 gene, provide new insights for the use of SRIs in chronic pain management.
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Affiliation(s)
- Cary Huang
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois; Department of Anesthesiology, NewYork-Presbyterian/Weill Cornell Medical Center, New York, New York.
| | - Andre J van Wijnen
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois; Department of Biochemistry, University of Vermont, Burlington, Vermont.
| | - Hee-Jeong Im
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center (JBVAMC), Chicago, Illinois.
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5
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Psilocybin for Depression: From Credibility to Feasibility, What's Missing? Pharmaceuticals (Basel) 2022; 16:ph16010068. [PMID: 36678564 PMCID: PMC9861656 DOI: 10.3390/ph16010068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/03/2023] Open
Abstract
Psilocybin has been suggested as a promising transdiagnostic treatment strategy for a wide range of psychiatric disorders. Recent findings showed that psychedelic-assisted/"psycholitic" psychotherapy should provide significant and sustained alleviation of depressive symptoms. However, to date, there have been several study limitations (e.g., small sample sizes, blinding, limited follow-up, highly screened treatment populations) and some health/political issues, including practitioners' experience, lack of standardized protocols, psychedelics' legal status, ethical concerns, and potential psychological/psychopathological/medical untoward effects. The focus here is on a range of clinical and methodological issues, also aiming at outlining some possible suggestions. We are confident that newer evidence, more precise protocols, and eventual reclassification policies may allow a better understanding of the real potential of psilocybin as a transdiagnostic therapeutic molecule.
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6
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Glatfelter GC, Pottie E, Partilla JS, Sherwood AM, Kaylo K, Pham DNK, Naeem M, Sammeta VR, DeBoer S, Golen JA, Hulley EB, Stove CP, Chadeayne AR, Manke DR, Baumann MH. Structure-Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice. ACS Pharmacol Transl Sci 2022; 5:1181-1196. [PMID: 36407948 PMCID: PMC9667540 DOI: 10.1021/acsptsci.2c00177] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Indexed: 11/06/2022]
Abstract
4-Phosphoryloxy-N,N-dimethyltryptamine (psilocybin) is a naturally occurring tertiary amine found in many mushroom species. Psilocybin is a prodrug for 4-hydroxy-N,N-dimethyltryptamine (psilocin), which induces psychedelic effects via agonist activity at the serotonin (5-HT) 2A receptor (5-HT2A). Several other 4-position ring-substituted tryptamines are present in psilocybin-containing mushrooms, including the secondary amine 4-phosphoryloxy-N-methyltryptamine (baeocystin) and the quaternary ammonium 4-phosphoryloxy-N,N,N-trimethyltryptamine (aeruginascin), but these compounds are not well studied. Here, we investigated the structure-activity relationships for psilocybin, baeocystin, and aeruginascin, as compared to their 4-acetoxy and 4-hydroxy analogues, using in vitro and in vivo methods. Broad receptor screening using radioligand binding assays in transfected cells revealed that secondary and tertiary tryptamines with either 4-acetoxy or 4-hydroxy substitutions display nanomolar affinity for most human 5-HT receptor subtypes tested, including the 5-HT2A and the serotonin 1A receptor (5-HT1A). The same compounds displayed affinity for 5-HT2A and 5-HT1A in mouse brain tissue in vitro and exhibited agonist efficacy in assays examining 5-HT2A-mediated calcium mobilization and β-arrestin 2 recruitment. In mouse experiments, only the tertiary amines psilocin, psilocybin, and 4-acetoxy-N,N-dimethyltryptamine (psilacetin) induced head twitch responses (ED50 0.11-0.29 mg/kg) indicative of psychedelic-like activity. Head twitches were blocked by 5-HT2A antagonist pretreatment, supporting 5-HT2A involvement. Both secondary and tertiary amines decreased body temperature and locomotor activity at higher doses, the effects of which were blocked by 5-HT1A antagonist pretreatment. Across all assays, the pharmacological effects of 4-acetoxy and 4-hydroxy compounds were similar, and these compounds were more potent than their 4-phosphoryloxy counterparts. Importantly, psilacetin appears to be a prodrug for psilocin that displays substantial serotonin receptor activities of its own.
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Affiliation(s)
- Grant C. Glatfelter
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
| | - Eline Pottie
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, 9000 Ghent, Belgium
| | - John S. Partilla
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
| | | | - Kristi Kaylo
- Usona
Institute, Madison, Wisconsin 53711, United States
| | - Duyen N. K. Pham
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Marilyn Naeem
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Vamshikrishna Reddy Sammeta
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Stacie DeBoer
- Department
of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - James A. Golen
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Elliott B. Hulley
- Department
of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Christophe P. Stove
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, 9000 Ghent, Belgium
| | | | - David R. Manke
- Department
of Chemistry & Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | - Michael H. Baumann
- Designer
Drug Research Unit, National Institute on
Drug Abuse Intramural Research Program, Baltimore, Maryland 21224, United States
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7
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Erkizia-Santamaría I, Alles-Pascual R, Horrillo I, Meana J, Ortega J. Serotonin 5-HT2A, 5-HT2c and 5-HT1A receptor involvement in the acute effects of psilocybin in mice. In vitro pharmacological profile and modulation of thermoregulation and head-twich response. Biomed Pharmacother 2022; 154:113612. [DOI: 10.1016/j.biopha.2022.113612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/12/2022] [Accepted: 08/24/2022] [Indexed: 11/02/2022] Open
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8
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Glatfelter GC, Chojnacki MR, McGriff SA, Wang T, Baumann MH. Automated Computer Software Assessment of 5-Hydroxytryptamine 2A Receptor-Mediated Head Twitch Responses from Video Recordings of Mice. ACS Pharmacol Transl Sci 2022; 5:321-330. [PMID: 35592434 PMCID: PMC9112414 DOI: 10.1021/acsptsci.1c00237] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Indexed: 02/08/2023]
Abstract
Psychedelics are a class of drugs that produce unique subjective effects via agonist actions at the 5-hydroxytryptamine 2A receptor (5-HT2A). The 5-HT2A-mediated head twitch response (HTR) in rodents is used as a reliable proxy for psychedelic drug activity in humans, but existing methods for measuring HTRs require surgery or time-consuming visual scoring. In the present work, we validated a simple noninvasive method for quantitating HTRs using computer-based analysis of experimental video recordings. Male C57BL/6J mice received injections of the 5-HT2 receptor agonist (±)2,5-dimethoxy-4-iodoamphetamine (DOI; 0.03-3 mg/kg, s.c.) and were placed into cylindrical arenas. High frame rate videos were recorded via cameras mounted above the arenas. Antagonist experiments, which entailed pretreatment with the 5-HT2A antagonist M100907 (0.01 or 0.1 mg/kg s.c.) prior to DOI (1 mg/kg s.c.), were also recorded. The experimental videos were analyzed for HTRs using a newly developed feature of a commercial software package and compared to visual scoring carried out by trained observers. As expected, DOI produced dose-related increases in HTRs, which were blocked by M100907. Computer scoring was positively correlated with visual scoring, and no statistical difference between the two methods was found. The software captured nearly all visually observed HTRs, false positives induced by other behaviors (e.g., grooming) were rare and easily identified, and results were improved by optimizing lighting conditions. Our findings demonstrate the utility of combining high frame rate video recordings with commercial software analyses to measure HTRs, validating an additional reliable method to study psychedelic-like drug activity in mice.
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Affiliation(s)
- Grant C. Glatfelter
- Designer
Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland 21224, United States
| | - Michael R. Chojnacki
- Designer
Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland 21224, United States
| | - Shelby A. McGriff
- Designer
Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland 21224, United States
| | - Tianpeng Wang
- Clever
Sys Inc., Reston, Virginia 20190, United
States
| | - Michael H. Baumann
- Designer
Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland 21224, United States
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9
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Sun Y, Chebolu S, Henry D, Lankireddy S, Darmani NA. An ontogenic study of receptor mechanisms by which acute administration of low-doses of methamphetamine suppresses DOI-induced 5-HT 2A-receptor mediated head-twitch response in mice. BMC Neurosci 2022; 23:2. [PMID: 34983399 PMCID: PMC8725525 DOI: 10.1186/s12868-021-00686-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 12/17/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Methamphetamine (MA) is a non-selective monoamine releaser and thus releases serotonin (5-HT), norepinephrine (NE) and dopamine (DA) from corresponding nerve terminals into synapses. DOI ((±)-2, 5-dimethoxy-4-iodoamphetamine) is a direct-acting serotonergic 5-HT2A/C receptor agonist and induces the head-twitch response (HTR) via stimulation of 5-HT2A receptor in mice. While more selective serotonin releasers such as d-fenfluramine evoke the HTR, monoamine reuptake blockers (e.g., cocaine) suppress the DOI-evoked HTR via indirect stimulation of serotonergic 5-HT1A- and adrenergic ɑ2-receptors. Since the induction of HTR by DOI is age-dependent, we investigated whether: (1) during development MA can evoke the HTR by itself, and (2) acute pretreatment with either the selective 5-HT2A receptor antagonist EMD 281014 or low-doses of MA can: (i) modulate the DOI-induced HTR in mice across postnatal days 20, 30 and 60, and (ii) alter the DOI-induced c-fos expression in mice prefrontal cortex (PFC). To further explore the possible modulatory effect of MA on DOI-induced HTR, we investigated whether blockade of inhibitory serotonergic 5-HT1A- or adrenergic ɑ2-receptors by corresponding selective antagonists (WAY 100635 or RS 79948, respectively), can prevent the effect of MA on DOI-induced HTR during aging. RESULTS Although neither EMD 281014 nor MA by themselves could evoke the HTR, acute pretreatment with either EMD 281014 (0.01, 0.05 and 0.1 mg/kg, i.p.) or MA (1, 2.5, 5 mg/kg, i.p.), dose-dependently suppressed the DOI-induced HTR across ages. While WAY 100635 significantly reversed the inhibitory effect of MA in 20- and 30-day old mice, RS 79948 failed to significantly counter MA's inhibitory effect. Moreover, DOI significantly increased c-fos expressions in several PFC regions. EMD 281014 prevented the DOI-induced increases in c-fos expression. Despite the inhibitory effect of MA on DOI-induced HTR, MA alone or in combination with DOI, significantly increased c-fos expression in several regions of the PFC. CONCLUSION The suppressive effect of MA on the DOI-evoked HTR appears to be mainly due to functional interactions between the HTR-inducing 5-HT2A receptor and the inhibitory 5-HT1A receptor. The MA-induced increase in c-fos expression in different PFC regions may be due to MA-evoked increases in synaptic concentrations of 5-HT, NE and/or DA.
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Affiliation(s)
- Yina Sun
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA, 91766, USA
| | - Seetha Chebolu
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA, 91766, USA
| | - Denise Henry
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA, 91766, USA
| | - Sandeep Lankireddy
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA, 91766, USA
| | - Nissar A Darmani
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA, 91766, USA.
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10
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Kaswan NK, Mohammed Izham NAB, Tengku Mohamad TAS, Sulaiman MR, Perimal EK. Cardamonin Modulates Neuropathic Pain through the Possible Involvement of Serotonergic 5-HT1A Receptor Pathway in CCI-Induced Neuropathic Pain Mice Model. Molecules 2021; 26:3677. [PMID: 34208700 PMCID: PMC8234694 DOI: 10.3390/molecules26123677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 12/14/2022] Open
Abstract
Cardamonin, a naturally occurring chalcone isolated from Alpinia species has shown to possess strong anti-inflammatory and anti-nociceptive activities. Previous studies have demonstrated that cardamonin exerts antihyperalgesic and antiallodynic properties in chronic constriction injury (CCI)-induced neuropathic pain animal model. However, the mechanisms underlying cardamonin's effect have yet to be fully understood. The present study aims to investigate the involvement of the serotonergic system in cardamonin induced antihyperalgesic and antiallodynic effects in CCI-induced neuropathic pain mice model. The neuropathic pain symptoms in the CCI mice model were assessed using Hargreaves Plantar test and von-Frey filament test on day 14 post-surgery. Central depletion of serotonin along the descending serotonergic pathway was done using ρ-chlorophenylalanine (PCPA, 100 mg/kg, i.p.), an inhibitor of serotonin synthesis for four consecutive days before cardamonin treatment, and was found to reverse the antihyperalgesic and antiallodynic effect produced by cardamonin. Pretreatment of the mice with several 5-HT receptor subtypes antagonists: methiothepin (5-HT1/6/77 receptor antagonist, 0.1 mg/kg), WAY 100635 (5-HT1A receptor antagonist, 1 mg/kg), isamoltane (5-HT1B receptor antagonist, 2.5 mg/kg), ketanserin (5-HT2A receptor antagonist, 0.3 mg/kg), and ondansetron (5-HT3 receptor antagonist, 0.5 mg/kg) were shown to abolish the effect of cardamonin induced antihyperalgesic and antiallodynic effects. Further evaluation of the 5-HT1A receptor subtype protein expressions reveals that cardamonin significantly upregulated its expression in the brainstem and spinal cord. Our results suggest that the serotonergic pathway is essential for cardamonin to exert its antineuropathic effect in CCI mice through the involvement of the 5-HT1A receptor subtype in the central nervous system.
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Affiliation(s)
- Nur Khalisah Kaswan
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM), Serdang 43400, Selangor, Malaysia; (N.K.K.); (N.A.B.M.I.); (T.A.S.T.M.); (M.R.S.)
| | - Noor Aishah Binti Mohammed Izham
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM), Serdang 43400, Selangor, Malaysia; (N.K.K.); (N.A.B.M.I.); (T.A.S.T.M.); (M.R.S.)
| | - Tengku Azam Shah Tengku Mohamad
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM), Serdang 43400, Selangor, Malaysia; (N.K.K.); (N.A.B.M.I.); (T.A.S.T.M.); (M.R.S.)
| | - Mohd Roslan Sulaiman
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM), Serdang 43400, Selangor, Malaysia; (N.K.K.); (N.A.B.M.I.); (T.A.S.T.M.); (M.R.S.)
| | - Enoch Kumar Perimal
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM), Serdang 43400, Selangor, Malaysia; (N.K.K.); (N.A.B.M.I.); (T.A.S.T.M.); (M.R.S.)
- Centre of Excellence for Nanoscale BioPhotonics, Australian Research Council, University of Adelaide, Adelaide, SA 5005, Australia
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11
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Sharma A, Mehan S. Targeting PI3K-AKT/mTOR signaling in the prevention of autism. Neurochem Int 2021; 147:105067. [PMID: 33992742 DOI: 10.1016/j.neuint.2021.105067] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/29/2021] [Accepted: 05/02/2021] [Indexed: 12/16/2022]
Abstract
PI3K-AKT/mTOR signaling pathway represents an essential signaling mechanism for mammalian enzyme-related receptors in transducing signals or biological processes such as cell development, differentiation, cell survival, protein synthesis, and metabolism. Upregulation of the PI3K-AKT/mTOR signaling pathway involves many human brain abnormalities, including autism and other neurological dysfunctions. Autism is a neurodevelopmental disorder associated with behavior and psychiatric illness. This research-based review discusses the functional relationship between the neuropathogenic factors associated with PI3K-AKT/mTOR signaling pathway. Ultimately causes autism-like conditions associated with genetic alterations, neuronal apoptosis, mitochondrial dysfunction, and neuroinflammation. Therefore, inhibition of the PI3K-AKT/mTOR signaling pathway may have an effective therapeutic value for autism treatment. The current review also summarizes the involvement of PI3K-AKT/mTOR signaling pathway inhibitors in the treatment of autism and other neurodegenerative disorders.
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Affiliation(s)
- Aarti Sharma
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Sidharth Mehan
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India.
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12
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Lee MY, Lin BF, Chan MH, Chen HH. Increased behavioral and neuronal responses to a hallucinogenic drug after adolescent toluene exposure in mice: Effects of antipsychotic treatment. Toxicology 2020; 445:152602. [PMID: 32980479 DOI: 10.1016/j.tox.2020.152602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/19/2020] [Accepted: 09/22/2020] [Indexed: 01/23/2023]
Abstract
Toluene has been characterized as a non-classical hallucinogen drug through activation of 5-HT2A receptors and antagonism of NMDA receptors. It remains unclear whether psychotic symptoms after long-term and intense toluene exposure are associated with abnormalities in 5-HT2A receptor function. The present study examined whether the responses to a hallucinogenic 5-HT2A receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) were altered in a mouse model of toluene psychosis. Male NMRI mice were subchronically treated with toluene during adolescence. Reciprocal social interaction test and novel object recognition test were conducted to confirm the persistent behavioral deficits in adulthood. Subsequently, DOI-induced head twitch, c-Fos and Egr-2 expression, field potentials in the medial prefrontal cortex (mPFC), and the levels of 5-HT2A, 5-HT1A and mGlu2 receptors in the mPFC were monitored. Toluene exposure during adolescence produced social and memory impairments and enhanced DOI-induced behavioral, molecular and electrophysiological responses, but did not change the levels of 5-HT2A, 5-HT1A or mGlu2 receptors in the mPFC. Moreover, the effects of haloperidol and risperidone on the behavioral deficits and hyper-responsiveness to DOI after adolescent toluene exposure were compared. When administered after adolescent toluene exposure, risperidone could reverse social withdrawal, cognitive impairment and hypersensitivity to DOI, whereas haloperidol was only beneficial for social withdrawal. These findings suggest that increased functionality of 5-HT2A receptors may play a critical role in solvent-induced psychosis and recommend the antipsychotics with more selective 5-HT2A receptor antagonism as the first-line treatment for solvent-induced psychosis.
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Affiliation(s)
- Mei-Yi Lee
- Center for Neuropsychiatric Research, National Health Research Institutes, 35 Keyan Rd. Zhunan, Miaoli, 35053, Taiwan
| | - Bih-Fen Lin
- Department of Laboratory Medicine and Biotechnology School of Medicine, Tzu Chi University, No. 701, Sec. 3, Zhongyang Rd., Hualien, 97004, Taiwan
| | - Ming-Huan Chan
- Institute of Neuroscience, National Chengchi University, NO. 64, Sec. 2, Zhinan Rd., Taipei, 11605, Taiwan; Research Center for Mind, Brain, and Learning, National Chengchi University, NO. 64, Sec. 2, Zhinan Rd., Taipei, 11605, Taiwan; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, 40402, Taiwan.
| | - Hwei-Hsien Chen
- Center for Neuropsychiatric Research, National Health Research Institutes, 35 Keyan Rd. Zhunan, Miaoli, 35053, Taiwan; Institute of Neuroscience, National Chengchi University, NO. 64, Sec. 2, Zhinan Rd., Taipei, 11605, Taiwan; Ph.D. Program in Tissue Engineering and Regenerative Medicine, National Chung Hsing University, No. 145, Xingda Rd., Taichung, 40227, Taiwan.
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13
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Commons KG, Linnros SE. Delayed Antidepressant Efficacy and the Desensitization Hypothesis. ACS Chem Neurosci 2019. [PMID: 30807103 DOI: 10.1021/acschemneuro.8b00698)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Many conventional antidepressants can quickly raise the levels of extracellular serotonin, yet their positive effects on mood ensues only weeks later. This delay in efficacy is a clinical problem that has proven difficult to overcome. Early investigation noted that the initial increases in extracellular serotonin engaged strong feedback inhibition of serotonin neurons via 5-HT1A autoreceptors, resulting in a profound reduction in their firing rate. Over the course of chronic treatment, however, firing rate returned to normal and the inhibition via 5-HT1A receptor agonists was attenuated. The coincident timeline of these phenomena led to the influential hypothesis that the relationship was causal and that gradual loss of feedback inhibition mediated by 5-HT1A receptors was critical to the delayed therapeutic onset. Simple and appealing, the desensitization hypothesis has taken strong hold, yet much of the supporting evidence is circumstantial and there are several observations that would refute a causal relationship. In particular, even though 5-HT1A receptors may desensitize, there is evidence that feedback inhibition mediated by remaining receptors persists. That is, baseline serotonin firing rate returns to normal not because of 5-HT1A desensitization but rather despite ongoing feedback inhibition. Thus, while 5-HT1A receptors remain important for emotional behavior, it may be other slow-adaptive changes triggered by antidepressants that allow for therapeutic effects, such as those involving glutamatergic synaptic plasticity.
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Affiliation(s)
- Kathryn G Commons
- Department of Anesthesiology, Perioperative and Pain Medicine , Boston Children's Hospital , Boston , Massachusetts 02115 , United States.,Department of Anesthesia , Harvard Medical School , Boston , Massachusetts 02115 , United States
| | - Sofia E Linnros
- Department of Anesthesiology, Perioperative and Pain Medicine , Boston Children's Hospital , Boston , Massachusetts 02115 , United States.,Department of Anesthesia , Harvard Medical School , Boston , Massachusetts 02115 , United States
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14
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Commons KG, Linnros SE. Delayed Antidepressant Efficacy and the Desensitization Hypothesis. ACS Chem Neurosci 2019; 10:3048-3052. [PMID: 30807103 DOI: 10.1021/acschemneuro.8b00698] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Many conventional antidepressants can quickly raise the levels of extracellular serotonin, yet their positive effects on mood ensues only weeks later. This delay in efficacy is a clinical problem that has proven difficult to overcome. Early investigation noted that the initial increases in extracellular serotonin engaged strong feedback inhibition of serotonin neurons via 5-HT1A autoreceptors, resulting in a profound reduction in their firing rate. Over the course of chronic treatment, however, firing rate returned to normal and the inhibition via 5-HT1A receptor agonists was attenuated. The coincident timeline of these phenomena led to the influential hypothesis that the relationship was causal and that gradual loss of feedback inhibition mediated by 5-HT1A receptors was critical to the delayed therapeutic onset. Simple and appealing, the desensitization hypothesis has taken strong hold, yet much of the supporting evidence is circumstantial and there are several observations that would refute a causal relationship. In particular, even though 5-HT1A receptors may desensitize, there is evidence that feedback inhibition mediated by remaining receptors persists. That is, baseline serotonin firing rate returns to normal not because of 5-HT1A desensitization but rather despite ongoing feedback inhibition. Thus, while 5-HT1A receptors remain important for emotional behavior, it may be other slow-adaptive changes triggered by antidepressants that allow for therapeutic effects, such as those involving glutamatergic synaptic plasticity.
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Affiliation(s)
- Kathryn G. Commons
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts 02115, United States
- Department of Anesthesia, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Sofia E. Linnros
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts 02115, United States
- Department of Anesthesia, Harvard Medical School, Boston, Massachusetts 02115, United States
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15
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Kulikova EA, Khotskin NV, Illarionova NB, Sorokin IE, Bazhenova EY, Kondaurova EM, Volcho KP, Khomenko TM, Salakhutdinov NF, Ponimaskin E, Naumenko VS, Kulikov AV. Inhibitor of Striatal-Enriched Protein Tyrosine Phosphatase, 8-(Trifluoromethyl)-1,2,3,4,5-Benzopentathiepin-6-Amine hydrochloride (TC-2153), Produces Antidepressant-Like Effect and Decreases Functional Activity and Protein Level of 5-HT 2A Receptor in the Brain. Neuroscience 2018; 394:220-231. [PMID: 30367948 DOI: 10.1016/j.neuroscience.2018.10.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/05/2018] [Accepted: 10/16/2018] [Indexed: 11/25/2022]
Abstract
The serotoninergic 5-HT2A receptor is involved in the mechanism of depression and antidepressant drugs action. Earlier we showed that striatal-enriched protein tyrosine phosphatase (STEP) inhibitor - 8-(trifluoromethyl)-1,2,3,4,5-benzopentathiepin-6-amine hydrochloride (TC-2153) affects both the brain serotoninergic system and the brain-derived neurotropic factor that are known to be involved in the psychopathology of depression. In the present study we investigated the effects of chronic TC-2153 administration on behavior in the standard battery of tests as well as the effects of acute and chronic TC-2153 treatment on the brain 5-HT2A receptors in mice. We obtained a prominent antidepressant-like effect of chronic TC-2153 treatment in the forced swim test without any adverse side effects on locomotor activity, anxiety, exploration, motor skill and obsessive-compulsive-like behavior. Moreover, both acute and chronic TC-2153 administration inhibited the functional activity of 5-HT2A receptors estimated by the number of 2,5-dimethoxy-4-iodoamphetamine (DOI, agonist of 5-HT2A receptors)-induced head-twitches. TC-2153 treatment also attenuated the DOI-induced c-fos expression in cortical and hippocampal neurons and reduced the 5-HT2A receptor protein level in the hippocampus and frontal cortex, but not in the striatum. Taken together, our combined data demonstrate that the antidepressant effect of STEP inhibitor TC-2153 could be mediated by its inhibitory properties towards the 5-HT2A receptor-mediated signaling.
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Affiliation(s)
- E A Kulikova
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia.
| | - N V Khotskin
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia
| | - N B Illarionova
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia
| | - I E Sorokin
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia
| | - E Y Bazhenova
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia
| | - E M Kondaurova
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia
| | - K P Volcho
- Novosibirsk Institute of Organic Chemistry, Siberian Division of Russian Academy of Sciences, Novosibirsk, Russia
| | - T M Khomenko
- Novosibirsk Institute of Organic Chemistry, Siberian Division of Russian Academy of Sciences, Novosibirsk, Russia
| | - N F Salakhutdinov
- Novosibirsk Institute of Organic Chemistry, Siberian Division of Russian Academy of Sciences, Novosibirsk, Russia
| | - E Ponimaskin
- Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - V S Naumenko
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia
| | - A V Kulikov
- Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Science, Novosibirsk, Russia
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16
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Babb JA, Linnros SE, Commons KG. Evidence for intact 5-HT 1A receptor-mediated feedback inhibition following sustained antidepressant treatment in a rat model of depression. Neuropharmacology 2018; 141:139-147. [PMID: 30170082 DOI: 10.1016/j.neuropharm.2018.08.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 08/06/2018] [Accepted: 08/25/2018] [Indexed: 01/12/2023]
Abstract
Serotonin (5-HT) neurons are strongly implicated in mood disorders such as depression and are importantly regulated by feedback inhibition mediated by 5-HT1A receptors. These receptors may play a role, albeit a poorly understood one, in the generation of mood disorders, treatment response to antidepressants and delayed therapeutic efficacy. Here we sought to gain insight into the role of 5-HT1A receptor-mediated feedback inhibition in these processes by studying Fos protein expression within serotonin neurons in a rat model of stress-related mood disorder, early life maternal separation (MS), combined with two-week treatment with the antidepressant fluoxetine (FLX) in adulthood. We gauged 5-HT1A receptor-mediated feedback inhibition by the ability of the antagonist, WAY-100635 (WAY), to disinhibit Fos expression in 5-HT neurons. We found that two-week FLX treatment dramatically inhibited Fos expression in serotonin neurons and that this effect was reversed by blocking 5-HT1A receptors with WAY. Together these observations reveal that after prolonged exposure to SSRIs, endogenous 5-HT1A receptors continue to exert feedback inhibition of serotonin neurons. Furthermore we found unique effects of pharmacological treatments after MS in that the WAY effect was greatest in MS rats treated with FLX, a phenomenon selective to the rostral 2/3 of the dorsal raphe nucleus (B7). These results indicate that the balance between activation and feedback inhibition of serotonin neurons in B7 is altered and uniquely sensitive to FLX after early-life stress.
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Affiliation(s)
- Jessica A Babb
- Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA; Department of Anesthesia, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA.
| | - Sofia E Linnros
- Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA; Department of Pharmaceutical Biosciences, Uppsala University, 751 05 Uppsala, Sweden.
| | - Kathryn G Commons
- Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA; Department of Anesthesia, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA.
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17
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Garcia LP, Witteveen JS, Middelman A, van Hulten JA, Martens GJM, Homberg JR, Kolk SM. Perturbed Developmental Serotonin Signaling Affects Prefrontal Catecholaminergic Innervation and Cortical Integrity. Mol Neurobiol 2018; 56:1405-1420. [PMID: 29948943 PMCID: PMC6400880 DOI: 10.1007/s12035-018-1105-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 05/03/2018] [Indexed: 11/26/2022]
Abstract
Proper development of the medial prefrontal cortex (mPFC), crucial for correct cognitive functioning, requires projections from, among others, the serotonergic (5-HT) and catecholaminergic systems, but it is unclear how these systems influence each other during development. Here, we describe the parallel development of the 5-HT and catecholaminergic prefrontal projection systems in rat and demonstrate a close engagement of both systems in the proximity of Cajal-Retzius cells. We further show that in the absence of the 5-HT transporter (5-HTT), not only the developing 5-HT but also the catecholaminergic system, including their projections towards the mPFC, are affected. In addition, the layer identity of the mPFC neurons and reelin-positive interneuron number and integration are altered in the absence of the 5-HTT. Together, our data demonstrate a functional interplay between the developing mPFC 5-HT and catecholaminergic systems, and call for a holistic approach in studying neurotransmitter systems-specific developmental consequences for adult behavior, to eventually allow the design of better treatment strategies for neuropsychiatric disorders.
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Affiliation(s)
- Lidiane P Garcia
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Josefine S Witteveen
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Anthonieke Middelman
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Cognitive Neuroscience, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Josephus A van Hulten
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Gerard J M Martens
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands
| | - Judith R Homberg
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Cognitive Neuroscience, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Sharon M Kolk
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Department of Molecular Animal Physiology, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, Geert Grooteplein Zuid 28, 6525 GA, Nijmegen, The Netherlands.
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18
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Benvenga MJ, Chaney SF, Baez M, Britton TC, Hornback WJ, Monn JA, Marek GJ. Metabotropic Glutamate 2 Receptors Play a Key Role in Modulating Head Twitches Induced by a Serotonergic Hallucinogen in Mice. Front Pharmacol 2018; 9:208. [PMID: 29599719 PMCID: PMC5862811 DOI: 10.3389/fphar.2018.00208] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 02/23/2018] [Indexed: 11/29/2022] Open
Abstract
There is substantial evidence that glutamate can modulate the effects of 5-hydroxytryptamine2A (5-HT2A) receptor activation through stimulation of metabotropic glutamate2/3 (mGlu2/3) receptors in the prefrontal cortex. Here we show that constitutive deletion of the mGlu2 gene profoundly attenuates an effect of 5-HT2A receptor activation using the mouse head twitch response (HTR). MGlu2 and mGlu3 receptor knockout (KO) as well as age-matched ICR (CD-1) wild type (WT) mice were administered (±)1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and observed for head twitch activity. DOI failed to produce significant head twitches in mGlu2 receptor KO mice at a dose 10-fold higher than the peak effective dose in WT or mGlu3 receptor KO mice. In addition, the mGlu2/3 receptor agonist LY379268, and the mGlu2 receptor positive allosteric modulator (PAM) CBiPES, potently blocked the HTR to DOI in WT and mGlu3 receptor KO mice. Conversely, the mGlu2/3 receptor antagonist LY341495 (10 mg/kg) increased the HTR produced by DOI (3 mg/kg) in mGlu3 receptor KO mice. Finally, the mGlu2 receptor potentiator CBiPES was able to attenuate the increase in the HTR produced by LY341495 in mGlu3 receptor KO mice. Taken together, all of these results are consistent with the hypothesis that that DOI-induced head twitches are modulated by mGlu2 receptor activation. These results also are in keeping with a critical autoreceptor function for mGlu2 receptors in the prefrontal cortex with differential effects of acute vs. chronic perturbation (e.g., constitutive mGlu2 receptor KO mice). The robust attenuation of DOI-induced head twitches in the mGlu2 receptor KO mice appears to reflect the critical role of glutamate in ongoing regulation of 5-HT2A receptors in the prefrontal cortex. Future experiments with inducible knockouts for the mGlu2 receptor and/or selective mGlu3 receptor agonists/PAMs/antagonists could provide an important tools in understanding glutamatergic modulation of prefrontal cortical 5-HT2A receptor function.
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Affiliation(s)
- Mark J Benvenga
- Neuroscience Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, United States.,Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, United States
| | - Stephen F Chaney
- Neuroscience Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, United States
| | - Melvyn Baez
- Neuroscience Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, United States
| | - Thomas C Britton
- Discovery Chemistry Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, United States
| | - William J Hornback
- Discovery Chemistry Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, United States
| | - James A Monn
- Discovery Chemistry Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, United States
| | - Gerard J Marek
- Neuroscience Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, United States
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19
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Receptor binding profiles and behavioral pharmacology of ring-substituted N,N-diallyltryptamine analogs. Neuropharmacology 2018; 142:231-239. [PMID: 29499272 DOI: 10.1016/j.neuropharm.2018.02.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/09/2018] [Accepted: 02/26/2018] [Indexed: 12/18/2022]
Abstract
Substantial effort has been devoted toward understanding the psychopharmacological effects of tryptamine hallucinogens, which are thought to be mediated by activation of 5-HT2A and 5-HT1A receptors. Recently, several psychoactive tryptamines based on the N,N-diallyltryptamine (DALT) scaffold have been encountered as recreational drugs. Despite the apparent widespread use of DALT derivatives in humans, little is known about their pharmacological properties. We compared the binding affinities of DALT and its 2-phenyl-, 4-acetoxy-, 4-hydroxy-, 5-methoxy-, 5-methoxy-2-methyl-, 5-fluoro-, 5-fluoro-2-methyl-, 5-bromo-, and 7-ethyl-derivatives at 45 receptor and transporter binding sites. Additionally, studies in C57BL/6 J mice examined whether these substances induce the head twitch response (HTR), a 5-HT2A receptor-mediated response that is widely used as a behavioral proxy for hallucinogen effects in humans. Most of the test drugs bound to serotonin receptors, σ sites, α2-adrenoceptors, dopaminergic D3 receptors, histaminergic H1 receptors, and the serotonin transporter. DALT and several of the ring-substituted derivatives were active in the HTR assay with the following rank order of potency: 4-acetoxy-DALT > 5-fluoro-DALT > 5-methoxy-DALT > 4-hydroxy-DALT > DALT > 5-bromo-DALT. 2-Phenyl-DALT, 5-methoxy-2-methyl-DALT, 5-fluoro-2-methyl-DALT, and 7-ethyl-DALT did not induce the HTR. HTR potency was not correlated with either 5-HT1A or 5-HT2A receptor binding affinity, but a multiple regression analysis indicated that 5-HT2A and 5-HT1A receptors make positive and negative contributions, respectively, to HTR potency (R2 = 0.8729). In addition to supporting the established role of 5-HT2A receptors in the HTR, these findings are consistent with evidence that 5-HT1A activation by tryptamine hallucinogens buffers their effects on HTR. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.
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20
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Brandt SD, Kavanagh PV, Twamley B, Westphal F, Elliott SP, Wallach J, Stratford A, Klein LM, McCorvy JD, Nichols DE, Halberstadt AL. Return of the lysergamides. Part IV: Analytical and pharmacological characterization of lysergic acid morpholide (LSM-775). Drug Test Anal 2018; 10:310-322. [PMID: 28585392 PMCID: PMC6230476 DOI: 10.1002/dta.2222] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 05/31/2017] [Accepted: 06/01/2017] [Indexed: 01/30/2023]
Abstract
Lysergic acid diethylamide (LSD) is perhaps one of the best-known psychoactive substances and many structural modifications of this prototypical lysergamide have been investigated. Several lysergamides were recently encountered as 'research chemicals' or new psychoactive substances (NPS). Although lysergic acid morpholide (LSM-775) appeared on the NPS market in 2013, there is disagreement in the literature regarding the potency and psychoactive properties of LSM-775 in humans. The present investigation attempts to address the gap of information that exists regarding the analytical profile and pharmacological effects of LSM-775. A powdered sample of LSM-775 was characterized by X-ray crystallography, nuclear magnetic resonance spectroscopy (NMR), gas chromatography mass spectrometry (GC-MS), high mass accuracy electrospray MS/MS, high performance liquid chromatography (HPLC) diode array detection, HPLC quadrupole MS, and GC solid-state infrared analysis. Screening for receptor affinity and functional efficacy revealed that LSM-775 acts as a nonselective agonist at 5-HT1A and 5-HT2A receptors. Head twitch studies were conducted in C57BL/6J mice to determine whether LSM-775 activates 5-HT2A receptors and produces hallucinogen-like effects in vivo. LSM-775 did not induce the head twitch response unless 5-HT1A receptors were blocked by pretreatment with the antagonist WAY-100,635 (1 mg/kg, subcutaneous). These findings suggest that 5-HT1A activation by LSM-775 masks its ability to induce the head twitch response, which is potentially consistent with reports in the literature indicating that LSM-775 is only capable of producing weak LSD-like effects in humans.
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Affiliation(s)
- Simon D. Brandt
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Pierce V. Kavanagh
- Department of Pharmacology and Therapeutics, School of Medicine, Trinity Centre for Health Sciences, Dublin 8, Ireland
| | - Brendan Twamley
- School of Chemistry, Trinity College Dublin, Dublin 2, Ireland
| | - Folker Westphal
- Section Narcotics/Toxicology, State Bureau of Criminal Investigation Schleswig-Holstein, Kiel, Germany
| | | | - Jason Wallach
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, University of the Sciences, Philadelphia, Pennsylvania, USA
| | | | - Landon M. Klein
- Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - John D. McCorvy
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - David E. Nichols
- Division of Chemical Biology and Medicinal Chemistry, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Adam L. Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, California, USA
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Abstract
Because of the ethical and regulatory hurdles associated with human studies, much of what is known about the psychopharmacology of hallucinogens has been derived from animal models. However, developing reliable animal models has proven to be a challenging task due to the complexity and variability of hallucinogen effects in humans. This chapter focuses on three animal models that are frequently used to test the effects of hallucinogens on unconditioned behavior: head twitch response (HTR), prepulse inhibition of startle (PPI), and exploratory behavior. The HTR has demonstrated considerable utility in the neurochemical actions of hallucinogens. However, the latter two models have clearer conceptual bridges to human phenomenology. Consistent with the known mechanism of action of hallucinogens in humans, the behavioral effects of hallucinogens in rodents are mediated primarily by activation of 5-HT2A receptors. There is evidence, however, that other receptors may play secondary roles. The structure-activity relationships (SAR) of hallucinogens are reviewed in relation to each model, with a focus on the HTR in rats and mice.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA.
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Mark A Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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Najar F, Nasehi M, Haeri-Rohani SA, Zarrindast MR. The involvement of medial septum 5-HT1 and 5-HT2 receptors on ACPA-induced memory consolidation deficit: possible role of TRPC3, TRPC6 and TRPV2. J Psychopharmacol 2015; 29:1200-8. [PMID: 26464456 DOI: 10.1177/0269881115609021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present study evaluates the roles of serotonergic receptors of the medial septum on amnesia induced by arachidonylcyclopropylamide (ACPA; as selective cannabinoid CB1 receptor agonist) in adult male Wistar rats. Cannulae were implanted in the medial septum of the brain of the rats. The animals were trained in a passive avoidance learning apparatus, and were tested 24 hours after training for step-through latency. Results indicated that post-training medial septum administration of CP94253 (5-HT1B/1D receptor agonist) and cinancerine (as 5-HT2 receptor antagonist) reduced the step-through latency showing an amnesic response, while GR127935 (5-HT1B/1D receptor antagonist) and αm5htm (as 5-HT2A/2B/2D receptor agonist) did not alter memory consolidation by themselves. On continuing the test, the results showed that CP94253 increased and GR127935 did not alter ACPA (0.02 µg/rat)-induced memory impairment, respectively. Other data indicated that αm5htm induced a modulatory effect, while cinancerine restored ACPA-induced amnesia. Using SKF-96365 (inhibitor of transient receptor potential TRPC3/6 and TRPV2 channels) demonstrated that TRPC3, TRPC3 and TRPV2 channels have a significant role, according to our results.
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Affiliation(s)
- Farzaneh Najar
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad Nasehi
- Cognitive and Neuroscience Research Center (CNRC), Medical Genomics Research Center and School of Advanced Sciences in Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran
| | - Seyed-Ali Haeri-Rohani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad-Reza Zarrindast
- Cognitive and Neuroscience Research Center (CNRC), Medical Genomics Research Center and School of Advanced Sciences in Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran Department of Pharmacology School of Medicine, Tehran University of Basic Sciences, Tehran, Iran Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran Substance Abuse and Dependence Research Center, University of School Welfare and Rehabilitation Sciences, Tehran Iran
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23
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Biased signalling: the instinctive skill of the cell in the selection of appropriate signalling pathways. Biochem J 2015; 470:155-67. [DOI: 10.1042/bj20150358] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
GPCRs (G-protein-coupled receptors) are members of a family of proteins which are generally regarded as the largest group of therapeutic drug targets. Ligands of GPCRs do not usually activate all cellular signalling pathways linked to a particular seven-transmembrane receptor in a uniform manner. The fundamental idea behind this concept is that each ligand has its own ability, while interacting with the receptor, to activate different signalling pathways (or a particular set of signalling pathways) and it is this concept which is known as biased signalling. The importance of biased signalling is that it may selectively activate biological responses to favour therapeutically beneficial signalling pathways and to avoid adverse effects. There are two levels of biased signalling. First, bias can arise from the ability of GPCRs to couple to a subset of the available G-protein subtypes: Gαs, Gαq/11, Gαi/o or Gα12/13. These subtypes produce the diverse effects of GPCRs by targeting different effectors. Secondly, biased GPCRs may differentially activate G-proteins or β-arrestins. β-Arrestins are ubiquitously expressed and function to terminate or inhibit classic G-protein signalling and initiate distinct β-arrestin-mediated signalling processes. The interplay of G-protein and β-arrestin signalling largely determines the cellular consequences of the administration of GPCR-targeted drugs. In the present review, we highlight the particular functionalities of biased signalling and discuss its biological effects subsequent to GPCR activation. We consider that biased signalling is potentially allowing a choice between signalling through ‘beneficial’ pathways and the avoidance of ‘harmful’ ones.
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Activation of 5-HT2a receptors in the basolateral amygdala promotes defeat-induced anxiety and the acquisition of conditioned defeat in Syrian hamsters. Neuropharmacology 2014; 90:102-12. [PMID: 25458113 DOI: 10.1016/j.neuropharm.2014.11.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 11/11/2014] [Accepted: 11/22/2014] [Indexed: 01/14/2023]
Abstract
Conditioned defeat is a model in Syrian hamsters (Mesocricetus auratus) in which normal territorial aggression is replaced by increased submissive and defensive behavior following acute social defeat. The conditioned defeat response involves both a fear-related memory for a specific opponent as well as anxiety-like behavior indicated by avoidance of novel conspecifics. We have previously shown that systemic injection of a 5-HT2a receptor antagonist reduces the acquisition of conditioned defeat. Because neural activity in the basolateral amygdala (BLA) is critical for the acquisition of conditioned defeat and BLA 5-HT2a receptors can modulate anxiety but have a limited effect on emotional memories, we investigated whether 5-HT2a receptor modulation alters defeat-induced anxiety but not defeat-related memories. We injected the 5-HT2a receptor antagonist MDL 11,939 (0 mM, 1.7 mM or 17 mM) or the 5-HT2a receptor agonist TCB-2 (0 mM, 8 mM or 80 mM) into the BLA prior to social defeat. We found that injection of MDL 11,939 into the BLA impaired acquisition of the conditioned defeat response and blocked defeat-induced anxiety in the open field, but did not significantly impair avoidance of former opponents in the Y-maze. Furthermore, we found that injection of TCB-2 into the BLA increased the acquisition of conditioned defeat and increased anxiety-like behavior in the open field, but did not alter avoidance of former opponents. Our data suggest that 5-HT2a receptor signaling in the BLA is both necessary and sufficient for the development of conditioned defeat, likely via modulation of defeat-induced anxiety.
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Long-lasting alterations in 5-HT2A receptor after a binge regimen of methamphetamine in mice. Int J Neuropsychopharmacol 2014; 17:1647-58. [PMID: 24763081 DOI: 10.1017/s1461145714000455] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The repeated administration of methamphetamine (MA) to animals in a single-day 'binge' dosing regimen produces damage to dopamine and serotonin terminals and psychosis-like behaviours similar to those observed in MA abusers. The present study aimed to examine the effects of MA binge exposure on 5-HT2A receptors, the subtype of serotonin receptors putatively involved in psychosis. ICR male mice were treated with MA (4 × 5 mg/kg) or saline at 2 h intervals. Recognition memory and social behaviours were sequentially evaluated by a novel location recognition test, a novel object recognition test, a social interaction and a nest-building test to confirm the persistent cognitive and behavioural impairments after this dosing regimen. Subsequently, a hallucinogenic 5-HT2A/2C receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI)-induced head-twitch, molecular and electrophysiological responses were monitored. Finally, the levels of 5-HT2C, 5-HT1A, 5-HT2A and mGlu2 receptors in the medial prefrontal cortex were determined. MA binge exposure produced recognition memory impairment, reduced social behaviours, and increased DOI-induced head-twitch response, c-Fos and Egr-2 expression and field potentials in the medial prefrontal cortex. Furthermore, MA binge exposure increased 5-HT2A and decreased mGlu2 receptor expression in the medial frontal cortex, whereas 5-HT2C and 5-HT1A receptors were unaffected. These data reveal that the increased behavioural, molecular and electrophysiological responses to DOI might be associated with an up-regulation of 5-HT2A receptors in the medial prefrontal cortex after MA binge exposure. Identifying the biochemical alterations that parallel the behavioural changes in a mouse model of MA binge exposure may facilitate targeting therapies for treatment of MA-related psychiatric disorders.
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26
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Gibbs ME, Hertz L. Serotonin mediation of early memory formation via 5-HT2B receptor-induced glycogenolysis in the day-old chick. Front Pharmacol 2014; 5:54. [PMID: 24744730 PMCID: PMC3978258 DOI: 10.3389/fphar.2014.00054] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 03/13/2014] [Indexed: 11/13/2022] Open
Abstract
Investigation of the effects of serotonin on memory formation in the chick revealed an action on at least two 5-HT receptors. Serotonin injected intracerebrally produced a biphasic effect on memory consolidation with enhancement at low doses and inhibition at higher doses. The non-selective 5-HT receptor antagonist methiothepin and the selective 5-HT2B/C receptor antagonist SB221284 both inhibited memory, suggesting actions of serotonin on at least two different receptor subtypes. The 5-HT2B/C and astrocyte-specific 5-HT receptor agonist, fluoxetine and paroxetine, enhanced memory and the effect was attributed to glycogenolysis. Inhibition of glycogenolysis with a low dose of DAB (1,4-dideoxy-1,4-imino-D-arabinitol) prevented both serotonin and fluoxetine from enhancing memory during short-term memory but not during intermediate memory. The role of serotonin on the 5-HT2B/C receptor appears to involve glycogen breakdown in astrocytes during short-term memory, whereas other published evidence attributes the second period of glycogenolysis to noradrenaline.
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Affiliation(s)
- Marie E Gibbs
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University Parkville, VIC, Australia
| | - Leif Hertz
- Department of Clinical Pharmacology, China Medical University Shenyang, China
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27
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Saunders C, Siuta M, Robertson SD, Davis AR, Sauer J, Matthies HJG, Gresch PJ, Airey D, Lindsley CW, Schetz JA, Niswender KD, Veenstra-Vanderweele JM, Galli A. Neuronal ablation of p-Akt at Ser473 leads to altered 5-HT1A/2A receptor function. Neurochem Int 2013; 73:113-121. [PMID: 24090638 DOI: 10.1016/j.neuint.2013.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 09/16/2013] [Accepted: 09/19/2013] [Indexed: 02/08/2023]
Abstract
The serotonergic system regulates a wide range of behavior, including mood and impulsivity, and its dysregulation has been associated with mood disorders, autism spectrum disorder, and addiction. Diabetes is a risk factor for these conditions. Insulin resistance in the brain is specifically associated with susceptibility to psychostimulant abuse. Here, we examined whether phosphorylation of Akt, a key regulator of the insulin signaling pathway, controls serotonin (5-HT) signaling. To explore how impairment in Akt function regulates 5-HT homeostasis, we used a brain-specific rictor knockout (KO) mouse model of impaired neuronal phosphorylation of Akt at Ser473. Cortical 5-HT1A and 5-HT2A receptor binding was significantly elevated in rictor KO mice. Concomitant with this elevated receptor expression, the 5-HT1A receptor agonist 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) led to an increased hypothermic response in rictor KO mice. The increased cortical 5-HT1A receptor density was associated with higher 5-HT1A receptor levels on the cortical cell surface. In contrast, rictor KO mice displayed significantly reduced head-twitch response (HTR) to the 5-HT2A/C agonist 2,5-dimethoxy-4-iodoamphetamine (DOI), with evidence of impaired 5-HT2A/C receptor signaling. In vitro, pharmacological inhibition of Akt significantly increased 5-HT1A receptor expression and attenuated DOI-induced 5-HT2A receptor signaling, thereby lending credence to the observed in vivo cross-talk between neuronal Akt signaling and 5-HT receptor regulation. These data reveal that defective central Akt function alters 5-HT signaling as well as 5-HT-associated behaviors, demonstrating a novel role for Akt in maintaining neuronal 5-HT receptor function.
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Affiliation(s)
- Christine Saunders
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Michael Siuta
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN
| | - Sabrina D Robertson
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN
| | - Adeola R Davis
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN
| | - Jennifer Sauer
- Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN
| | - Heinrich J G Matthies
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN
| | - Paul J Gresch
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - David Airey
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - John A Schetz
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, TX
| | - Kevin D Niswender
- Department of Medicine Vanderbilt University Medical Center, Nashville, TN
| | - Jeremy M Veenstra-Vanderweele
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN.,Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN
| | - Aurelio Galli
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN.,Department of Neuroscience Program in Substance Abuse, Vanderbilt University Medical Center, Nashville, TN
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Haberzettl R, Bert B, Fink H, Fox MA. Animal models of the serotonin syndrome: a systematic review. Behav Brain Res 2013; 256:328-45. [PMID: 24004848 DOI: 10.1016/j.bbr.2013.08.045] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 08/26/2013] [Accepted: 08/28/2013] [Indexed: 11/16/2022]
Abstract
The serotonin syndrome (SS) is a potentially life-threatening disorder in humans which is induced by ingestion of an overdose or by combination of two or more serotonin (5-HT)-enhancing drugs. In animals, acute administration of direct and indirect 5-HT agonists also leads to a set of behavioral and autonomic responses. In the current review, we provide an overview of the existing versions of the animal model of the SS. With a focus on studies in rats and mice, we analyze the frequency of behavioral and autonomic responses following administration of 5-HT-enhancing drugs and direct 5-HT agonists administered alone or in combination, and we briefly discuss the receptor mediation of these responses. Considering species differences, we identify a distinct set of behavioral and autonomic responses that are consistently observed following administration of direct and indirect 5-HT agonists. Finally, we discuss the importance of a standardized assessment of SS responses in rodents and the utility of animal models of the SS in translational studies, and provide suggestions for future research.
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Affiliation(s)
- Robert Haberzettl
- Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, Koserstrasse 20, 14195 Berlin, Germany
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29
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Araragi N, Mlinar B, Baccini G, Gutknecht L, Lesch KP, Corradetti R. Conservation of 5-HT1A receptor-mediated autoinhibition of serotonin (5-HT) neurons in mice with altered 5-HT homeostasis. Front Pharmacol 2013; 4:97. [PMID: 23935583 PMCID: PMC3731744 DOI: 10.3389/fphar.2013.00097] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/17/2013] [Indexed: 12/23/2022] Open
Abstract
Firing activity of serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) is controlled by inhibitory somatodendritic 5-HT1A autoreceptors. This autoinhibitory mechanism is implicated in the etiology of disorders of emotion regulation, such as anxiety disorders and depression, as well as in the mechanism of antidepressant action. Here, we investigated how persistent alterations in brain 5-HT availability affect autoinhibition in two genetically modified mouse models lacking critical mediators of serotonergic transmission: 5-HT transporter knockout (Sert-/-) and tryptophan hydroxylase-2 knockout (Tph2-/-) mice. The degree of autoinhibition was assessed by loose-seal cell-attached recording in DRN slices. First, application of the 5-HT1A-selective agonist R(+)-8-hydroxy-2-(di-n-propylamino)tetralin showed mild sensitization and marked desensitization of 5-HT1A receptors in Tph2-/- mice and Sert-/- mice, respectively. While 5-HT neurons from Tph2-/- mice did not display autoinhibition in response to L-tryptophan, autoinhibition of these neurons was unaltered in Sert-/- mice despite marked desensitization of their 5-HT1A autoreceptors. When the Tph2-dependent 5-HT synthesis step was bypassed by application of 5-hydroxy-L-tryptophan (5-HTP), neurons from both Tph2-/- and Sert-/- mice decreased their firing rates at significantly lower concentrations of 5-HTP compared to wildtype controls. Our findings demonstrate that, as opposed to the prevalent view, sensitivity of somatodendritic 5-HT1A receptors does not predict the magnitude of 5-HT neuron autoinhibition. Changes in 5-HT1A receptor sensitivity may rather be seen as an adaptive mechanism to keep autoinhibition functioning in response to extremely altered levels of extracellular 5-HT resulting from targeted inactivation of mediators of serotonergic signaling.
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Affiliation(s)
- Naozumi Araragi
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Wuerzburg Wuerzburg, Germany
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30
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Fox MA, Panessiti MG, Hall FS, Uhl GR, Murphy DL. An evaluation of the serotonin system and perseverative, compulsive, stereotypical, and hyperactive behaviors in dopamine transporter (DAT) knockout mice. Psychopharmacology (Berl) 2013; 227:685-95. [PMID: 23417514 DOI: 10.1007/s00213-013-2988-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 01/17/2013] [Indexed: 12/11/2022]
Abstract
RATIONALE Mice lacking the dopamine transporter (DAT) display major behavioral alterations that include hyperactivity, perseverative locomotor patterns, and reduced prepulse inhibition of the acoustic startle reflex. OBJECTIVES The objectives of this study were to investigate perseverative, compulsive, stereotypical, and hyperactive behaviors, as well as serotonin and its involvement with these behaviors, in DAT gene-altered mice. RESULTS In the open field, mean turn angle and meandering were decreased in DAT knockout (DAT-KO) mice. DAT-KO mice displayed increased hyperactivity, increased velocity, less time immobile, and a failure to habituate over time in the open field unlike their DAT wildtype (DAT-WT) and heterozygous (DAT-HET) littermates. DAT-KO mice buried fewer marbles than DAT-WT and -HET mice in an assessment of compulsive-like behaviors, likely due to extreme hyperactivity and related inattention. Stereotypical head weaving was increased in untreated DAT-KO mice. Following administration of the 5-HT1A/7 agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), stereotypical head weaving and forepaw treading were increased more in DAT-KO mice than in DAT-WT or -HET mice. By contrast, head twitches induced by treatment with the 5-HT2A/2C agonist (±)-2,5-dimethoxy-4-iodophenyl-2-aminopropane (DOI) were similar in mice of all three DAT genotypes. 5-HT1A autoreceptor function was intact in DAT-KO mice. Compared to DAT-WT mice, serotonin levels were increased in DAT-HET and -KO mice in frontal cortex and hippocampus, respectively, and serotonin turnover rates were increased ∼30 % in the striatum of DAT-KO mice. CONCLUSIONS These findings extend and confirm prior behavioral and biochemical characterization of DAT-KO mice. Hyperactivity, stereotypy, and perseverative behaviors are increased in these mice, with brain-area specific increases in serotonin levels and serotonin turnover, and marked increases in postsynaptic 5-HT1A receptor-mediated stereotypic responses.
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Affiliation(s)
- Meredith A Fox
- Laboratory of Clinical Science, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Building 10-3D41, MSC 1264, Bethesda, MD 20892, USA.
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Halberstadt AL, Geyer MA. Characterization of the head-twitch response induced by hallucinogens in mice: detection of the behavior based on the dynamics of head movement. Psychopharmacology (Berl) 2013; 227:727-39. [PMID: 23407781 PMCID: PMC3866102 DOI: 10.1007/s00213-013-3006-z] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 01/21/2013] [Indexed: 02/05/2023]
Abstract
RATIONALE The head-twitch response (HTR) is a rapid side-to-side rotational head movement that occurs in rats and mice after administration of serotonergic hallucinogens and other 5-HT2A agonists. The HTR is widely used as a behavioral assay for 5-HT2A activation and to probe for interactions between the 5-HT2A receptor and other transmitter systems. OBJECTIVE High-speed video recordings were used to analyze the head movement that occurs during head twitches in C57BL/6J mice. Experiments were also conducted in C57BL/6J mice to determine whether a head-mounted magnet and a magnetometer coil could be used to detect the HTR induced by serotonergic hallucinations based on the dynamics of the response. RESULTS Head movement during the HTR was highly rhythmic and occurred within a specific frequency range (mean head movement frequency of 90.3 Hz). Head twitches produced wave-like oscillations of magnetometer coil voltage that matched the frequency of head movement during the response. The magnetometer coil detected the HTR induced by the serotonergic hallucinogens 2,5-dimethoxy-4-iodoamphetamine (DOI; 0.25, 0.5, and 1.0 mg/kg, i.p.) and lysergic acid diethylamide (LSD; 0.05, 0.1, 0.2, and 0.4 mg/kg, i.p.) with extremely high sensitivity and specificity. Magnetometer coil recordings demonstrated that the non-hallucinogenic compounds (+)-amphetamine (2.5 and 5.0 mg/kg, i.p.) and lisuride (0.8, 1.6, and 3.2 mg/kg, i.p.) did not induce the HTR. CONCLUSIONS These studies confirm that a magnetometer coil can be used to detect the HTR induced by hallucinogens. The use of magnetometer-based HTR detection provides a high-throughput, semi-automated assay for this behavior, and offers several advantages over traditional assessment methods.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0804, USA.
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Stewart AM, Cachat J, Gaikwad S, Robinson KS, Gebhardt M, Kalueff AV. Perspectives on experimental models of serotonin syndrome in zebrafish. Neurochem Int 2013; 62:893-902. [DOI: 10.1016/j.neuint.2013.02.018] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 02/10/2013] [Accepted: 02/14/2013] [Indexed: 01/07/2023]
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Bulley S, Liu Y, Ripps H, Shen W. Taurine activates delayed rectifier Kv channels via a metabotropic pathway in retinal neurons. J Physiol 2012; 591:123-32. [PMID: 23045337 DOI: 10.1113/jphysiol.2012.243147] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Taurine is one of the most abundant amino acids in the retina, throughout the CNS, and in heart and muscle cells. In keeping with its broad tissue distribution, taurine serves as a modulator of numerous basic processes, such as enzyme activity, cell development, myocardial function and cytoprotection. Despite this multitude of functional roles, the precise mechanism underlying taurine's actions has not yet been identified. In this study we report findings that indicate a novel role for taurine in the regulation of voltage-gated delayed rectifier potassium (K(V)) channels in retinal neurons by means of a metabotropic receptor pathway. The metabotropic taurine response was insensitive to the Cl(-) channel blockers, picrotoxin and strychnine, but it was inhibited by a specific serotonin 5-HT(2A) receptor antagonist, MDL11939. Moreover, we found that taurine enhanced K(V) channels via intracellular protein kinase C-mediated pathways. When 5-HT(2A) receptors were expressed in human embryonic kidney cells, taurine and AL34662, a non-specific 5-HT(2) receptor activator, produced a similar regulation of K(IR) channels. In sum, this study provides new evidence that taurine activates a serotonin system, apparently via 5-HT(2A) receptors and related intracellular pathways.
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Affiliation(s)
- Simon Bulley
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA
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Renoir T, Pang TYC, Zajac MS, Chan G, Du X, Leang L, Chevarin C, Lanfumey L, Hannan AJ. Treatment of depressive-like behaviour in Huntington's disease mice by chronic sertraline and exercise. Br J Pharmacol 2012; 165:1375-89. [PMID: 21718306 DOI: 10.1111/j.1476-5381.2011.01567.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Depression is the most common psychiatric disorder in Huntington's disease (HD) patients. Women are more prone to develop depression and such susceptibility might be related to 5-hydroxytryptaminergic (serotonergic) dysregulation. EXPERIMENTAL APPROACH We performed tests of depression-related behaviours on female R6/1 HD mice that had been chronically treated with sertraline or provided with running-wheels. Functional assessments of 5-HT(1A) and 5-HT(2A) receptors were performed by measuring behavioural and physiological responses following administration of specific agonists, in combination with analysis of hippocampal gene expression. Finally we assessed the effect of exercise on hippocampal cell proliferation. KEY RESULTS Female HD mice recorded increased immobility time in the forced-swimming test, reduced saccharin preference and a hyperthermic response to stress compared with wild-type animals. These alterations were improved by chronic sertraline treatment. Wheel-running also resulted in similar improvements with the exception of saccharin preference but failed to correct the hippocampal cell proliferation deficits displayed by HD mice. The benefits of sertraline treatment and exercise involved altered 5-HT(1A) autoreceptor function, as demonstrated by modulation of the exaggerated 8-OH-DPAT-induced hypothermia exhibited by female HD mice. On the other hand, sertraline treatment was unable to restore the reduced 5-HT(1A) and 5-HT(2) heteroceptor function observed in HD animals. CONCLUSIONS AND IMPLICATIONS We report for the first time a crucial role for 5-HT(1A) autoreceptor function in mediating the sex-specific depressive-like phenotype of female R6/1 HD mice. Our data further support a differential effect of chronic sertraline treatment and exercise on hippocampal cell proliferation despite common behavioural benefits.
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Affiliation(s)
- Thibault Renoir
- Howard Florey Institute, Florey Neuroscience Institutes, University of Melbourne, Parkville, Victoria, Australia.
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Genetic variation in 5-hydroxytryptamine transporter expression causes adaptive changes in 5-HT₄ receptor levels. Int J Neuropsychopharmacol 2012; 15:1099-107. [PMID: 21846421 DOI: 10.1017/s1461145711001258] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Genetic variation in 5-HT transporter (5-HTT) expression is a key risk factor for psychiatric disorder and has been linked to changes in the expression of certain 5-HT receptor subtypes. This study investigated the effect of variation in 5-HTT expression on 5-HT₄ receptor levels in both 5-HTT knockout (KO) and overexpressing (OE) mice using autoradiography with the selective 5-HT₄ receptor radioligand, [³H]SB207145. Compared to wild-type (5-HTT⁺/⁺) controls, homozygous 5-HTT KO mice (5-HTT⁻/⁻) had reduced 5-HT₄ receptor binding site density in all brain regions examined (35-65% of 5-HTT⁺/⁺). In contrast, the density of 5-HT₄ receptor binding sites was not significantly different between heterozygous 5-HTT KO mice (5-HTT⁻/⁺) and 5-HTT⁺/⁺ mice. The 5-HT synthesis inhibitor p-chlorophenylalanine (250 mg/kg twice daily for 3 d) abolished the difference in 5-HT₄ binding between 5-HTT⁻/⁻ and 5-HTT⁺/⁺ mice in all brain regions. Compared to wild-type (WT) littermate controls, 5-HTT OE mice had increased 5-HT₄ binding density across all brain regions, except amygdala (118-164% of WT) and this difference between genotypes was reduced by the 5-HTT inhibitor, fluoxetine (20 mg/kg twice daily, 3 d). Together, these findings suggest that variation in 5-HTT expression causes adaptive changes in 5-HT₄ receptor levels which are directly linked to alterations in 5-HT availability.
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Williams AA, Ingram WM, Levine S, Resnik J, Kamel CM, Lish JR, Elizalde DI, Janowski SA, Shoker J, Kozlenkov A, González-Maeso J, Gallitano AL. Reduced levels of serotonin 2A receptors underlie resistance of Egr3-deficient mice to locomotor suppression by clozapine. Neuropsychopharmacology 2012; 37:2285-98. [PMID: 22692564 PMCID: PMC3422493 DOI: 10.1038/npp.2012.81] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 04/06/2012] [Accepted: 04/26/2012] [Indexed: 02/06/2023]
Abstract
The immediate-early gene early growth response 3 (Egr3) is associated with schizophrenia and expressed at reduced levels in postmortem patients' brains. We have previously reported that Egr3-deficient (Egr3(-/-)) mice display reduced sensitivity to the sedating effects of clozapine compared with wild-type (WT) littermates, paralleling the heightened tolerance of schizophrenia patients to antipsychotic side effects. In this study, we have used a pharmacological dissection approach to identify a neurotransmitter receptor defect in Egr3(-/-) mice that may mediate their resistance to the locomotor suppressive effects of clozapine. We report that this response is specific to second-generation antipsychotic agents (SGAs), as first-generation medications suppress the locomotor activity of Egr3(-/-) and WT mice to a similar degree. Further, in contrast to the leading theory that sedation by clozapine results from anti-histaminergic effects, we show that H1 histamine receptors are not responsible for this effect in C57BL/6 mice. Instead, selective serotonin 2A receptor (5HT(2A)R) antagonists ketanserin and MDL-11939 replicate the effect of SGAs, repressing the activity in WT mice at a dosage that fails to suppress the activity of Egr3(-/-) mice. Radioligand binding revealed nearly 70% reduction in 5HT(2A)R expression in the prefrontal cortex of Egr3(-/-) mice compared with controls. Egr3(-/-) mice also exhibit a decreased head-twitch response to 5HT(2A)R agonist 1-(2,5-dimethoxy 4-iodophenyl)-2-amino propane (DOI). These findings provide a mechanism to explain the reduced sensitivity of Egr3(-/-) mice to the locomotor suppressive effects of SGAs, and suggest that 5HT(2A)Rs may also contribute to the sedating properties of these medications in humans. Moreover, as the deficit in cortical 5HT(2A)R in Egr3(-/-) mice aligns with numerous studies reporting decreased 5HT(2A)R levels in the brains of schizophrenia patients, and the gene encoding the 5HT(2A)R is itself a leading schizophrenia candidate gene, these findings suggest a potential mechanism by which putative dysfunction in EGR3 in humans may influence risk for schizophrenia.
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Affiliation(s)
| | - Wendy M Ingram
- Department of Molecular and Cell Biology, Life Sciences Addition, University of California, Berkeley, CA, USA
| | - Sarah Levine
- University of Arizona College of Medicine—Tucson, Tucson, AZ, USA
| | - Jack Resnik
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, USA
| | - Christy M Kamel
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, USA
| | - James R Lish
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, USA
| | - Diana I Elizalde
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, USA
| | - Scott A Janowski
- University of Arizona College of Medicine—Tucson, Tucson, AZ, USA
| | - Joseph Shoker
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, USA
| | - Alexey Kozlenkov
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, USA
| | - Javier González-Maeso
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, USA
- Department of Neurology, Mount Sinai School of Medicine, New York, NY, USA
| | - Amelia L Gallitano
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, USA
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37
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Canal CE, Morgan D. Head-twitch response in rodents induced by the hallucinogen 2,5-dimethoxy-4-iodoamphetamine: a comprehensive history, a re-evaluation of mechanisms, and its utility as a model. Drug Test Anal 2012; 4:556-76. [PMID: 22517680 DOI: 10.1002/dta.1333] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/09/2012] [Accepted: 01/10/2012] [Indexed: 11/06/2022]
Abstract
Two primary animal models persist for assessing hallucinogenic potential of novel compounds and for examining the pharmacological and neurobiological substrates underlying the actions of classical hallucinogens, the two-lever drug discrimination procedure and the drug-induced head-twitch response (HTR) in rodents. The substituted amphetamine hallucinogen, serotonin 2 (5-HT(2) ) receptor agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI) has emerged as the most popular pharmacological tool used in HTR studies of hallucinogens. Synthesizing classic, recent, and relatively overlooked findings, addressing ostensibly conflicting observations, and considering contemporary theories in receptor and behavioural pharmacology, this review provides an up-to-date and comprehensive synopsis of DOI and the HTR model, from neural mechanisms to utility for understanding psychiatric diseases. Also presented is support for the argument that, although both the two-lever drug discrimination and the HTR models in rodents are useful for uncovering receptors, interacting proteins, intracellular signalling pathways, and neurochemical processes affected by DOI and related classical hallucinogens, results from both models suggest they are not reporting hallucinogenic experiences in animals.
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Affiliation(s)
- Clint E Canal
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA.
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38
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Abstract
5-Hydroxytryptamine (5-HT or serotonin) is an important neurotransmitter for a number of brain functions and widely distributed throughout the brain. Physiological and pharmacological relationship between 5-HT1A receptors and serotonin transporter (5-HTT) in the regulation of 5-HT neurotransmission has now been documented. A relationship between 5-HT1A receptors and 5-HTT is also suggested by the pathophysiology of depression and the mechanism of action of antidepressants. We have scanned 42 healthy adults with both [11C] WAY-100635 and [11C] DASB to investigate the anatomical co-distribution of multiple serotonergic markers. We hypothesized that lower 5-HTT densities in the dorsal raphe nucleus (DRN) and limbic regions will be accompanied by lower 5-HT1A receptor density in the same regions, contributing to the 5-HT1A receptor desensitization. In addition, variations in DRN 5-HT1A receptor density can theoretically influence the density and/or function of other serotonin receptor subtypes and the 5-HTT consequent to changes in serotonergic tone. In a comparatively large sample of volunteers, we have shown that the relationship between 5-HT1A and 5-HTT PET indices was complex. We were unable to demonstrate robust, intra-regional relationships between 5-HT1A and 5-HTT densities. Inter-regionally, DRN 5-HT1A receptors were related to cortical (temporal and frontal regions) and paralimbic (insula), but not limbic 5-HTT. This latter finding may reflect differences in 5-HT tone between individuals, and highlights probable substrates sensitive to variations in DRN 5-HT function.
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39
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Neumann ID, Wegener G, Homberg JR, Cohen H, Slattery DA, Zohar J, Olivier JDA, Mathé AA. Animal models of depression and anxiety: What do they tell us about human condition? Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:1357-75. [PMID: 21129431 DOI: 10.1016/j.pnpbp.2010.11.028] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 10/24/2010] [Accepted: 11/19/2010] [Indexed: 01/07/2023]
Abstract
While modern neurobiology methods are necessary they are not sufficient to elucidate etiology and pathophysiology of affective disorders and develop new treatments. Achievement of these goals is contingent on applying cutting edge methods on appropriate disease models. In this review, the authors present four rodent models with good face-, construct-, and predictive-validity: the Flinders Sensitive rat line (FSL); the genetically "anxious" High Anxiety-like Behavior (HAB) line; the serotonin transporter knockout 5-HTT(-/-) rat and mouse lines; and the post-traumatic stress disorder (PTSD) model induced by exposure to predator scent, that they have employed to investigate the nature of depression and anxiety.
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Affiliation(s)
- I D Neumann
- Dept of Behavioural Neuroendocrinology, Faculty of Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
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40
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Gould GG, Hensler JG, Burke TF, Benno RH, Onaivi ES, Daws LC. Density and function of central serotonin (5-HT) transporters, 5-HT1A and 5-HT2A receptors, and effects of their targeting on BTBR T+tf/J mouse social behavior. J Neurochem 2011; 116:291-303. [PMID: 21070242 PMCID: PMC3012263 DOI: 10.1111/j.1471-4159.2010.07104.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BTBR mice are potentially useful tools for autism research because their behavior parallels core social interaction impairments and restricted-repetitive behaviors. Altered regulation of central serotonin (5-HT) neurotransmission may underlie such behavioral deficits. To test this, we compared 5-HT transporter (SERT), 5-HT(1A) and 5-HT(2A) receptor densities among BTBR and C57 strains. Autoradiographic [(3) H] cyanoimipramine (1 nM) binding to SERT was 20-30% lower throughout the adult BTBR brain as compared to C57BL/10J mice. In hippocampal membrane homogenates, [(3) H] citalopram maximal binding (B(max) ) to SERT was 95 ± 13 fmol/mg protein in BTBR and 171 ± 20 fmol/mg protein in C57BL/6J mice, and the BTBR dissociation constant (K(D) ) was 2.0 ± 0.3 nM versus 1.1 ± 0.2 in C57BL/6J mice. Hippocampal 5-HT(1A) and 5-HT(2A) receptor binding was similar among strains. However, 8-OH-DPAT-stimulated [(35) S] GTPγS binding in the BTBR hippocampal CA(1) region was 28% higher, indicating elevated 5-HT(1A) capacity to activate G-proteins. In BTBR mice, the SERT blocker, fluoxetine (10 mg/kg) and the 5-HT(1A) receptor partial-agonist, buspirone (2 mg/kg) enhanced social interactions. The D(2) /5-HT(2) receptor antagonist, risperidone (0.1 mg/kg) reduced marble burying, but failed to improve sociability. Overall, altered SERT and/or 5-HT(1A) functionality in hippocampus could contribute to the relatively low sociability of BTBR mice.
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MESH Headings
- Animals
- Brain/drug effects
- Brain/metabolism
- Brain/physiology
- Buspirone/pharmacology
- Fluoxetine/pharmacology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Protein Binding/physiology
- Protein Transport
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptor, Serotonin, 5-HT1A/physiology
- Receptor, Serotonin, 5-HT2A/metabolism
- Receptor, Serotonin, 5-HT2A/physiology
- Serotonin Plasma Membrane Transport Proteins/metabolism
- Serotonin Plasma Membrane Transport Proteins/physiology
- Social Behavior
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Affiliation(s)
- Georgianna G Gould
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA.
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Jennings KA, Lesch KP, Sharp T, Cragg SJ. Non-linear relationship between 5-HT transporter gene expression and frequency sensitivity of 5-HT signals. J Neurochem 2010; 115:965-73. [PMID: 20854367 DOI: 10.1111/j.1471-4159.2010.07001.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Much evidence suggests that variation in expression of the 5-hydroxytryptamine (5-HT) transporter (5-HTT) is linked to risk of psychiatric illness, but the neurobiological basis of this association is uncertain. In this study, we investigated the impact of variation in 5-HTT expression on subsecond fluctuations in extracellular 5-HT concentrations ([5-HT](o) ). Stimulus-evoked [5-HT](o) was detected using fast-scan cyclic voltammetry at carbon-fibre microelectrodes in the substantia nigra in brain slices from 5-HTT knockout (KO) and 5-HTT over-expressing (OE) mice. Compared with wild-type (WT) controls, evoked [5-HT](o) was greater in KO and less in OE mice. In WT controls, evoked [5-HT](o) was frequency-sensitive; however, in both KO and OE mice, evoked [5-HT](o) showed a striking loss of frequency sensitivity. The latter was observed in WT mice after application of a 5-HTT blocker. These data show that while variation in 5-HTT expression modified the peak magnitude of [5-HT](o) evoked by any given stimulus in a gene dose dependent manner, there was a non-linear relationship between 5-HTT expression and frequency sensitivity. Overall, the findings suggest that variation in 5-HTT expression has a marked effect on frequency sensitivity which is a fundamental property of normal 5-HT transmission.
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