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Rahdar M, Davoudi S, Dehghan S, Javan M, Hosseinmardi N, Behzadi G, Janahmadi M. Reversal of electrophysiological and behavioral deficits mediated by 5-HT7 receptor upregulation following LP-211 treatment in an autistic-like rat model induced by prenatal valproic acid exposure. Neuropharmacology 2024; 257:110057. [PMID: 38964596 DOI: 10.1016/j.neuropharm.2024.110057] [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: 03/10/2024] [Revised: 06/11/2024] [Accepted: 06/27/2024] [Indexed: 07/06/2024]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by alterations and imbalances in multiple brain neurochemical systems, particularly the serotonergic neurotransmission. This includes changes in serotonin (5-HT) levels, aberrations in 5-HT transporter activity, and decreased synthesis and expression of 5-HT receptors (5-HT7Rs). The exact role of the brain 5-HT system in the development of ASD remains unclear, with conflicting evidence on its involvement. Recently, we have reported research has shown a significant decrease in serotonergic neurons originating from the raphe nuclei and projecting to the CA1 region of the dorsal hippocampus in autistic-like rats. Additionally, we have shown that chronic activation of 5-HT7Rs reverses the effects of autism induction on synaptic plasticity. However, the functional significance of 5-HT7Rs at the cellular level is still not fully understood. This study presents new evidence indicating an upregulation of 5-HT7R in the CA1 subregion of the hippocampus following the induction of autism. The present account also demonstrates that activation of 5-HT7R with its agonist LP-211 can reverse electrophysiological abnormalities in hippocampal pyramidal neurons in a rat model of autism induced by prenatal exposure to VPA. Additionally, in vivo administration of LP-211 resulted in improvements in motor coordination, novel object recognition, and a reduction in stereotypic behaviors in autistic-like offspring. The findings suggest that dysregulated expression of 5-HT7Rs may play a role in the pathophysiology of ASD, and that agonists like LP-211 could potentially be explored as a pharmacological treatment for autism spectrum disorder.
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Affiliation(s)
- Mona Rahdar
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shima Davoudi
- Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Samaneh Dehghan
- Stem Cell and Regenerative Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Javan
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Narges Hosseinmardi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Gila Behzadi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Neuroscience Research Center and Dep. of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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2
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Luo YJ, Bao H, Crowther A, Li YD, Chen ZK, Tart DS, Asrican B, Zhang L, Song J. Sex-specific expression of distinct serotonin receptors mediates stress vulnerability of adult hippocampal neural stem cells in mice. Cell Rep 2024; 43:114140. [PMID: 38656873 PMCID: PMC11193935 DOI: 10.1016/j.celrep.2024.114140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/14/2023] [Accepted: 04/08/2024] [Indexed: 04/26/2024] Open
Abstract
Women are more vulnerable to stress and have a higher likelihood of developing mood disorders. The serotonin (5HT) system has been highly implicated in stress response and mood regulation. However, sex-dependent mechanisms underlying serotonergic regulation of stress vulnerability remain poorly understood. Here, we report that adult hippocampal neural stem cells (NSCs) of the Ascl1 lineage (Ascl1-NSCs) in female mice express functional 5HT1A receptors (5HT1ARs), and selective deletion of 5HT1ARs in Ascl1-NSCs decreases the Ascl1-NSC pool only in females. Mechanistically, 5HT1AR deletion in Ascl1-NSCs of females leads to 5HT-induced depolarization mediated by upregulation of 5HT7Rs. Furthermore, repeated restraint stress (RRS) impairs Ascl1-NSC maintenance through a 5HT1AR-mediated mechanism. By contrast, Ascl1-NSCs in males express 5HT7R receptors (5HT7Rs) that are downregulated by RRS, thus maintaining the Ascl1-NSC pool. These findings suggest that sex-specific expression of distinct 5HTRs and their differential interactions with stress may underlie sex differences in stress vulnerability.
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Affiliation(s)
- Yan-Jia Luo
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Hechen Bao
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Andrew Crowther
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Curriculum, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Ya-Dong Li
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA; Songjiang Research Institute, Songjiang Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Emotions and Affective Disorders, Shanghai 201699, China
| | - Ze-Ka Chen
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Dalton S Tart
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Brent Asrican
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Libo Zhang
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Juan Song
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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Shu Y, Hasenstaub A, McCormick DA. The h-current controls cortical recurrent network activity through modulation of dendrosomatic communication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548753. [PMID: 37502942 PMCID: PMC10370005 DOI: 10.1101/2023.07.12.548753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
A fundamental feature of the cerebral cortex is the ability to rapidly turn on and off maintained activity within ensembles of neurons through recurrent excitation balanced by inhibition. Here we demonstrate that reduction of the h-current, which is especially prominent in pyramidal cell dendrites, strongly increases the ability of local cortical networks to generate maintained recurrent activity. Reduction of the h-current resulted in hyperpolarization and increase in input resistance of both the somata and apical dendrites of layer 5 pyramidal cells, while strongly increasing the dendrosomatic transfer of low (<20 Hz) frequencies, causing an increased responsiveness to dynamic clamp-induced recurrent network-like activity injected into the dendrites and substantially increasing the duration of spontaneous Up states. We propose that modulation of the h-current may strongly control the ability of cortical networks to generate recurrent persistent activity and the formation and dissolution of neuronal ensembles.
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Affiliation(s)
- Yousheng Shu
- The Fudan University Fenglin Campus, 131 Dong’an Road, Xuhui District, Shanghai
| | - Andrea Hasenstaub
- Department of Otolaryngology-Head and Neck Surgery (OHNS), University of California, San Francisco, 675 Nelson Rising Lane, #514B, San Francisco CA 94158
| | - David A. McCormick
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510; Institute of Neuroscience, University of Oregon, Eugene, OR 97403
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4
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Zhang K, Han Y, Zhang P, Zheng Y, Cheng A. Comparison of fluorescence biosensors and whole-cell patch clamp recording in detecting ACh, NE, and 5-HT. Front Cell Neurosci 2023; 17:1166480. [PMID: 37333890 PMCID: PMC10272411 DOI: 10.3389/fncel.2023.1166480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 05/15/2023] [Indexed: 06/20/2023] Open
Abstract
The communication between neurons and, in some cases, between neurons and non-neuronal cells, through neurotransmission plays a crucial role in various physiological and pathological processes. Despite its importance, the neuromodulatory transmission in most tissues and organs remains poorly understood due to the limitations of current tools for direct measurement of neuromodulatory transmitters. In order to study the functional roles of neuromodulatory transmitters in animal behaviors and brain disorders, new fluorescent sensors based on bacterial periplasmic binding proteins (PBPs) and G-protein coupled receptors have been developed, but their results have not been compared to or multiplexed with traditional methods such as electrophysiological recordings. In this study, a multiplexed method was developed to measure acetylcholine (ACh), norepinephrine (NE), and serotonin (5-HT) in cultured rat hippocampal slices using simultaneous whole-cell patch clamp recordings and genetically encoded fluorescence sensor imaging. The strengths and weaknesses of each technique were compared, and the results showed that both techniques did not interfere with each other. In general, genetically encoded sensors GRABNE and GRAB5HT1.0 showed better stability compared to electrophysiological recordings in detecting NE and 5-HT, while electrophysiological recordings had faster temporal kinetics in reporting ACh. Moreover, genetically encoded sensors mainly report the presynaptic neurotransmitter release while electrophysiological recordings provide more information of the activation of downstream receptors. In sum, this study demonstrates the use of combined techniques to measure neurotransmitter dynamics and highlights the potential for future multianalyte monitoring.
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Affiliation(s)
- Kun Zhang
- Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Frontiers Science Center of Cellular Homeostasis and Human Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yanfei Han
- Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Frontiers Science Center of Cellular Homeostasis and Human Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peng Zhang
- Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Frontiers Science Center of Cellular Homeostasis and Human Diseases, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuqiong Zheng
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Aobing Cheng
- Department of Anesthesiology, Guangzhou First People’s Hospital, South China University of Technology, Guangzhou, Guangdong, China
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5
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Kitayama E, Kimura M, Ouchi T, Furusawa M, Shibukawa Y. Functional Expression of IP, 5-HT 4, D 1, A 2A, and VIP Receptors in Human Odontoblast Cell Line. Biomolecules 2023; 13:879. [PMID: 37371459 DOI: 10.3390/biom13060879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/26/2023] [Accepted: 05/18/2023] [Indexed: 06/29/2023] Open
Abstract
Odontoblasts are involved in sensory generation as sensory receptor cells and in dentin formation. We previously reported that an increase in intracellular cAMP levels by cannabinoid 1 receptor activation induces Ca2+ influx via transient receptor potential vanilloid subfamily member 1 channels in odontoblasts, indicating that intracellular cAMP/Ca2+ signal coupling is involved in dentinal pain generation and reactionary dentin formation. Here, intracellular cAMP dynamics in cultured human odontoblasts were investigated to understand the detailed expression patterns of the intracellular cAMP signaling pathway activated by the Gs protein-coupled receptor and to clarify its role in cellular functions. The presence of plasma membrane Gαs as well as prostaglandin I2 (IP), 5-hydroxytryptamine 5-HT4 (5-HT4), dopamine D1 (D1), adenosine A2A (A2A), and vasoactive intestinal polypeptide (VIP) receptor immunoreactivity was observed in human odontoblasts. In the presence of extracellular Ca2+, the application of agonists for the IP (beraprost), 5-HT4 (BIMU8), D1 (SKF83959), A2A (PSB0777), and VIP (VIP) receptors increased intracellular cAMP levels. This increase in cAMP levels was inhibited by the application of the adenylyl cyclase (AC) inhibitor SQ22536 and each receptor antagonist, dose-dependently. These results suggested that odontoblasts express Gs protein-coupled IP, 5-HT4, D1, A2A, and VIP receptors. In addition, activation of these receptors increased intracellular cAMP levels by activating AC in odontoblasts.
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Affiliation(s)
- Eri Kitayama
- Department of Physiology, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan
- Department of Endodontics, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Maki Kimura
- Department of Physiology, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Takehito Ouchi
- Department of Physiology, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Masahiro Furusawa
- Department of Endodontics, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Yoshiyuki Shibukawa
- Department of Physiology, Tokyo Dental College, 2-9-18, Kanda-Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan
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6
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Wulff AB, Nichols CD, Thompson SM. Preclinical perspectives on the mechanisms underlying the therapeutic actions of psilocybin in psychiatric disorders. Neuropharmacology 2023; 231:109504. [PMID: 36921889 DOI: 10.1016/j.neuropharm.2023.109504] [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: 02/02/2023] [Revised: 02/14/2023] [Accepted: 03/11/2023] [Indexed: 03/14/2023]
Abstract
Psychedelic compounds have shown extraordinary potential in treating a wide range of neuropsychiatric disorders. Psilocybin, for example, has now been shown in several clinical trials to induce a rapid (within days) and persistent (3-12 months) improvement in human treatment-resistant depression and other neuropsychiatric conditions. Here we review the preclinical models and experimental approaches that have been used to study the neurobiological actions of psychedelic drugs. We further summarize the insights these studies have provided into the possible mechanisms underlying the induction of their therapeutic actions, including the receptors to which psychedelics bind and the second messenger signaling cascades that they activate. We also discuss potential biological processes that psychedelics may alter to produce the lasting amelioration of symptoms, including improvements in synaptic structure and function and suppression of inflammation. Improved mechanistic understanding of psychedelic drug actions will aid in the advancement of these promising new medicines.
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Affiliation(s)
- Andreas B Wulff
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Charles D Nichols
- Department of Pharmacology and Experimental Therapeutics, LSU Health Sciences Center, New Orleans, LA, 70112, USA
| | - Scott M Thompson
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA; Department of Psychiatry, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
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7
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Wu X, Yan Q, Liu L, Xue X, Yao W, Li X, Li W, Ding S, Xia Y, Zhang D, Zhu F. Domesticated HERV-W env contributes to the activation of the small conductance Ca 2+-activated K + type 2 channels via decreased 5-HT4 receptor in recent-onset schizophrenia. Virol Sin 2023; 38:9-22. [PMID: 36007838 PMCID: PMC10006216 DOI: 10.1016/j.virs.2022.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022] Open
Abstract
The human endogenous retroviruses type W family envelope (HERV-W env) gene is located on chromosome 7q21-22. Our previous studies show that HERV-W env is elevated in schizophrenia and HERV-W env can increase calcium influx. Additionally, the 5-HTergic system and particularly 5-hydroxytryptamine (5-HT) receptors play a prominent role in the pathogenesis and treatment of schizophrenia. 5-hydroxytryptamine receptor 4 (5-HT4R) agonist can block calcium channels. However, the underlying relationship between HERV-W env and 5-HT4R in the etiology of schizophrenia has not been revealed. Here, we used enzyme-linked immunosorbent assay to detect the concentration of HERV-W env and 5-HT4R in the plasma of patients with schizophrenia and we found that there were decreased levels of 5-HT4R and a negative correlation between 5-HT4R and HERV-W env in schizophrenia. Overexpression of HERV-W env decreased the transcription and protein levels of 5-HT4R but increased small conductance Ca2+-activated K+ type 2 channels (SK2) expression levels. Further studies revealed that HERV-W env could interact with 5-HT4R. Additionally, luciferase assay showed that an essential region (-364 to -176 from the transcription start site) in the SK2 promoter was required for HERV-W env-induced SK2 expression. Importantly, 5-HT4R participated in the regulation of SK2 expression and promoter activity. Electrophysiological recordings suggested that HERV-W env could increase SK2 channel currents and the increase of SK2 currents was inhibited by 5-HT4R. In conclusion, HERV-W env could activate SK2 channels via decreased 5-HT4R, which might exhibit a novel mechanism for HERV-W env to influence neuronal activity in schizophrenia.
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Affiliation(s)
- Xiulin Wu
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Qiujin Yan
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | | | - Xing Xue
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Wei Yao
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Xuhang Li
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Wenshi Li
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Shuang Ding
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yaru Xia
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Dongyan Zhang
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Fan Zhu
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China; Hubei Province Key Laboratory of Allergy & Immunology, Wuhan University, Wuhan, 430071, China.
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8
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Bardoni R. Serotonergic 5-HT 7 Receptors as Modulators of the Nociceptive System. Curr Neuropharmacol 2023; 21:1548-1557. [PMID: 36453491 PMCID: PMC10472814 DOI: 10.2174/1570159x21666221129101800] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 10/18/2022] [Accepted: 11/01/2022] [Indexed: 12/03/2022] Open
Abstract
The biogenic amine serotonin modulates pain perception by activating several types of serotonergic receptors, including the 5-HT7 type. These receptors are widely expressed along the pain axis, both peripherally, on primary nociceptors, and centrally, in the spinal cord and the brain. The role of 5-HT7 receptors in modulating pain has been explored in vivo in different models of inflammatory and neuropathic pain. While most studies have reported an antinociceptive effect of 5-HT7 receptor activation, some authors have suggested a pronociceptive action. Differences in pain models, animal species and gender, receptor types, agonists, and route of administration could explain these discrepancies. In this mini-review, some of the main findings concerning the function of 5-HT7 receptors in the pain system have been presented. The expression patterns of the receptors at the different levels of the pain axis, along with the cellular mechanisms involved in their activity, have been described. Alterations in receptor expression and/or function in different pain models and the role of 5-HT7 receptors in controlling pain transmission have also been discussed. Finally, some of the future perspectives in this field have been outlined.
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Affiliation(s)
- Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena, and Reggio Emilia, Modena, Italy
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9
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Comitato A, Lacivita E, Leopoldo M, Bardoni R. 5-HT7 Receptors Regulate Excitatory-Inhibitory Balance in Mouse Spinal Cord Dorsal Horn. Front Mol Neurosci 2022; 15:946159. [PMID: 35875663 PMCID: PMC9298498 DOI: 10.3389/fnmol.2022.946159] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/13/2022] [Indexed: 11/30/2022] Open
Abstract
Serotonergic receptors of the 5-HT7 type (5-HT7Rs) are widely expressed in the central nervous system (CNS), where they modulate several functions, such as pain. Behavioral experiments in vivo have shown both anti- and pro-nociceptive actions of 5-HT7Rs, although an analgesic effect seems to be prevalent. In the spinal cord dorsal horn, the mechanisms involved in 5-HT7R-mediated synaptic modulation are still poorly understood, especially those regarding the control of synaptic inhibition. The present study investigated the modulation exerted by 5-HT7Rs on dorsal horn excitatory and inhibitory synaptic circuits, by performing patch-clamp recordings from lamina II neurons in mouse spinal cord slices. Our results show that applying the selective 5-HT7 agonist LP-211 facilitates glutamatergic release by enhancing the frequency of spontaneous postsynaptic currents (sEPSCs) and increasing the peak amplitude of excitatory postsynaptic currents (EPSCs) evoked by dorsal root stimulation. The effects on sEPSCs were still observed in the presence of the 5-HT1A antagonist WAY-100635, while the 5-HT7 antagonist SB-269970 blocked them. LP-211 was also able to increase the release of gamma-aminobutyric acid (GABA) and glycine, as shown by the increase of spontaneous inhibitory currents (sIPSC) frequency and evoked inhibitory postsynaptic currents (IPSC) amplitude. LP-211 was proved to be more effective in potentiating synaptic inhibition as compared to excitation: consistently, 5-HT7R activation significantly enhanced the excitability of tonic firing neurons, mainly corresponding to inhibitory interneurons. Our data bring new insights into the mechanisms of synaptic modulation mediated by 5-HT7Rs in the dorsal horn. Stronger impact on synaptic inhibition supports the hypothesis that these receptors may play an anti-nociceptive role in the spinal cord of naïve animals.
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Affiliation(s)
- Antonella Comitato
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Enza Lacivita
- Department of Pharmacy – Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Marcello Leopoldo
- Department of Pharmacy – Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- *Correspondence: Rita Bardoni,
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10
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Abstract
Cognitive impairment affects up to 80% of patients with Parkinson's disease (PD) and is associated with poor quality of life. PD cognitive dysfunction includes poor working memory, impairments in executive function and difficulty in set-shifting. The pathophysiology underlying cognitive impairment in PD is still poorly understood, but there is evidence to support involvements of the cholinergic, dopaminergic, and noradrenergic systems. Only rivastigmine, an acetyl- and butyrylcholinesterase inhibitor, is efficacious for the treatment of PD dementia, which limits management of cognitive impairment in PD. Whereas the role of the serotonergic system in PD cognition is less understood, through its interactions with other neurotransmitters systems, namely, the cholinergic system, it may be implicated in cognitive processes. In this chapter, we provide an overview of the pharmacological, clinical and pathological evidence that implicates the serotonergic system in mediating cognition in PD.
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11
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Lyman KA, Han Y, Zhou C, Renteria I, Besing GL, Kurz JE, Chetkovich DM. Hippocampal cAMP regulates HCN channel function on two time scales with differential effects on animal behavior. Sci Transl Med 2021; 13:eabl4580. [PMID: 34818058 DOI: 10.1126/scitranslmed.abl4580] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Kyle A Lyman
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Chicago, IL 60611, USA.,Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA.,Department of Neurology, Stanford University, 453 Quarry Road, Palo Alto, CA 94304, USA
| | - Ye Han
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Isabelle Renteria
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Gai-Linn Besing
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Jonathan E Kurz
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, 225 E. Chicago Ave., Chicago, IL 60611, USA
| | - Dane M Chetkovich
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
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12
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Solas M, Van Dam D, Janssens J, Ocariz U, Vermeiren Y, De Deyn PP, Ramirez MJ. 5-HT 7 receptors in Alzheimer's disease. Neurochem Int 2021; 150:105185. [PMID: 34555475 DOI: 10.1016/j.neuint.2021.105185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 09/01/2021] [Accepted: 09/12/2021] [Indexed: 10/20/2022]
Abstract
Even though the involvement of serotonin (5-hydroxytryptamine; 5-HT) and its receptors in Alzheimer's disease (AD) is widely accepted, data on the expression and the role of 5-HT7 receptors in AD is relatively limited. Therefore, the objective of the present work was to study the expression of serotonergic 5-HT7 receptors in postmortem samples of AD brains and correlate it with neurotransmitter levels, cognition and behavior. The study population consisted of clinically well-characterized and neuropathologically confirmed AD patients (n = 42) and age-matched control subjects (n = 18). Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and high-performance liquid chromatography were performed on Brodmann area (BA) 7, BA10, BA22, BA24, hippocampus, amygdala, thalamus and cerebellum to measure mRNA levels of 5-HT7 receptors (HTR7), as well as the concentrations of various monoamine neurotransmitters and their metabolites. Decreased levels of HTR7 mRNA were observed in BA10. A significant association was observed between HTR7 levels in BA10 and BEHAVE-AD cluster B (hallucinations) (rs(28) = 0.444, P < 0.05). In addition, a negative correlation was observed between HTR7 levels in BA10 and both MHPG concentrations in this brain region (rs(45) = -0.311; P < 0.05), and DOPAC levels in the amygdala (rs(42) = -0.311; P < 0.05). Quite surprisingly, no association was found between HTR7 levels and cognitive status. Altogether, this study supports the notion of the involvement of 5-HT7 receptors in psychotic symptoms in AD, suggesting the interest of testing antagonist acting at this receptor to specifically treat psychotic symptoms in this illness.
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Affiliation(s)
- Maite Solas
- Dpt Pharmacology and Toxicology, University of Navarra, 31008, Pamplona, Spain; IdISNA, Navarra Institute for Health Research, 31008, Pamplona, Spain
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Department of Neurology and Alzheimer Center Groningen, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Jana Janssens
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - U Ocariz
- Dpt Pharmacology and Toxicology, University of Navarra, 31008, Pamplona, Spain
| | - Yannick Vermeiren
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Department of Neurology and Alzheimer Center Groningen, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Peter Paul De Deyn
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Department of Neurology and Alzheimer Center Groningen, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Maria J Ramirez
- Dpt Pharmacology and Toxicology, University of Navarra, 31008, Pamplona, Spain; IdISNA, Navarra Institute for Health Research, 31008, Pamplona, Spain.
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13
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Bombardi C, Grandis A, Pivac N, Sagud M, Lucas G, Chagraoui A, Lemaire-Mayo V, De Deurwaerdère P, Di Giovanni G. Serotonin modulation of hippocampal functions: From anatomy to neurotherapeutics. PROGRESS IN BRAIN RESEARCH 2021; 261:83-158. [PMID: 33785139 DOI: 10.1016/bs.pbr.2021.01.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The hippocampal region receives a dense serotoninergic innervation originating from both medial and dorsal raphe nuclei. This innervation regulates hippocampal activity through the activation of distinct receptor families that are expressed in excitatory and inhibitory neurons, terminals of several afferent neurotransmitter systems, and glial cells. Preclinical and clinical studies indicate that hippocampal dysfunctions are involved in learning and memory deficits, dementia, Alzheimer's disease, epilepsy and mood disorders such as anxiety, depression and post-traumatic syndrome disorder, whereas the hippocampus participates also in the therapeutic mechanisms of numerous medicines. Not surprisingly, several drugs acting via 5-HT mechanisms are efficacious to some extent in some diseases and the link between 5-HT and the hippocampus although clear remains difficult to untangle. For this reason, we review reported data concerning the distribution and the functional roles of the 5-HT receptors in the hippocampal region in health and disease. The impact of the 5-HT systems on the hippocampal function is such that the research of new 5-HT mechanisms and drugs is still very active. It concerns notably drugs acting at the 5-HT1A,2A,2C,4,6 receptor subtypes, in addition to the already existing drugs including the selective serotonin reuptake inhibitors.
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Affiliation(s)
- Cristiano Bombardi
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
| | - Annamaria Grandis
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Nela Pivac
- Division of Molecular Medicine, Rudier Boskovic Institute, Zagreb, Croatia
| | - Marina Sagud
- Clinical Hospital Center Zagreb and School of Medicine University of Zagreb, Zagreb, Croatia
| | - Guillaume Lucas
- Neurocentre Magendie, INSERM 1215, Université de Bordeaux, Bordeaux, France
| | - Abdeslam Chagraoui
- Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine of Normandy (IRIB), Normandie University, UNIROUEN, INSERM U1239, Rouen, France; Department of Medical Biochemistry, Rouen University Hospital, Rouen, France
| | - Valérie Lemaire-Mayo
- Centre National de la Recherche Scientifique, Institut des Neurosciences Intégratives et Cognitives d'Aquitaine, UMR 5287, Bordeaux, France
| | - Philippe De Deurwaerdère
- Centre National de la Recherche Scientifique, Institut des Neurosciences Intégratives et Cognitives d'Aquitaine, UMR 5287, Bordeaux, France
| | - Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Neuroscience Division, School of Biosciences, Cardiff University, Cardiff, United Kingdom
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14
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Okubo R, Hasegawa T, Fukuyama K, Shiroyama T, Okada M. Current Limitations and Candidate Potential of 5-HT7 Receptor Antagonism in Psychiatric Pharmacotherapy. Front Psychiatry 2021; 12:623684. [PMID: 33679481 PMCID: PMC7930824 DOI: 10.3389/fpsyt.2021.623684] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/29/2021] [Indexed: 12/13/2022] Open
Abstract
Several mood-stabilizing atypical antipsychotics and antidepressants weakly block serotonin (5-HT) receptor type-7 (5-HT7R); however, the contributions of 5-HT7R antagonism to clinical efficacy and pathophysiology are yet to be clarified. A novel mood-stabilizing antipsychotic agent, lurasidone exhibits predominant binding affinity to 5-HT7R when compared with other monoamine receptors. To date, we have failed to discover the superior clinical efficacy of lurasidone on schizophrenia, mood, or anxiety disorders when compared with conventional mood-stabilizing atypical antipsychotics; however, numerous preclinical findings have indicated the possible potential of 5-HT7R antagonism against several neuropsychiatric disorders, as well as the generation of novel therapeutic options that could not be expected with conventional atypical antipsychotics. Traditional experimental techniques, electrophysiology, and microdialysis have demonstrated that the effects of 5-HT receptor type-1A (5-HT1AR) and 5-HT7R on neurotransmission are in contrast, but the effect of 5-HT1AR is more predominant than that of 5-HT7R, resulting in an insufficient understanding of the 5-HT7R function in the field of psychopharmacology. Accumulating knowledge regarding the pharmacodynamic profiles of 5-HT7R suggests that 5-HT7R is one of the key players in the establishment and remodeling of neural development and cytoarchitecture during the early developmental stage to the mature brain, and dysfunction or modulation of 5-HT7R is linked to the pathogenesis/pathophysiology of neuropsychiatric and neurodevelopmental disorders. In this review, to explore candidate novel applications for the treatment of several neuropsychiatric disorders, including mood disorders, schizophrenia, and other cognitive disturbance disorders, we discuss perspectives of psychopharmacology regarding the effects of 5-HT7R antagonism on transmission and intracellular signaling systems, based on preclinical findings.
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Affiliation(s)
- Ruri Okubo
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Toshiki Hasegawa
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Kouji Fukuyama
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Takashi Shiroyama
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Motohiro Okada
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
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15
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Siwiec M, Kusek M, Sowa JE, Tokarski K, Hess G. 5-HT 7 receptors increase the excitability of hippocampal CA1 pyramidal neurons by inhibiting the A-type potassium current. Neuropharmacology 2020; 177:108248. [PMID: 32736087 DOI: 10.1016/j.neuropharm.2020.108248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 06/11/2020] [Accepted: 07/20/2020] [Indexed: 11/30/2022]
Abstract
Accumulating evidence suggests a widespread role of serotonin 5-HT7 receptors (5-HT7Rs) in the physiology of cognitive and affective processing. However, we still lack insights into 5-HT7R electrophysiology. Studies analyzing the 5-HT7R-mediated changes in CA1 pyramidal neuron activity revealed that 5-HT7R activation leads to the opening of hyperpolarization-activated cyclic nucleotide-gated cation channels (HCNs). However, our group and others have shown that CA1 pyramidal cells increase their excitability following 5-HT7R activation, an effect which cannot be explained by HCN channel opening. This suggests a different ionic mechanism might be responsible. To investigate this, we performed whole-cell patch clamp recordings of CA1 pyramidal cells in rat brain slices. It was found that acute 5-HT7R activation increased membrane excitability and decreased spiking latency. Both effects were blocked by a selective 5-HT7R antagonist. Spike latency in CA1 pyramidal cells is known to be regulated by transient outward voltage-dependent A-type potassium channels. Subsequent voltage clamp recordings revealed that acute 5-HT7R activation inhibited A-type potassium currents. Pharmacological block of Kv4.2/4.3 potassium channel subunits prevented the 5-HT7R agonist-induced changes in excitability and spiking latency, whereas blocking HCN channels had no influence on these effects. Taken together, the results reveal an ionic mechanism previously not known to be associated with 5-HT7R activation. Inhibition of A-type potassium channels can fully account for increased CA1 pyramidal cell excitability after 5-HT7R activation. These results can help explain a number of behavioral and physiological findings and will hopefully lead to a better understanding of 5-HT7 receptor signaling in health and disease.
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Affiliation(s)
- Marcin Siwiec
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Krakow, Poland.
| | - Magdalena Kusek
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Krakow, Poland
| | - Joanna Ewa Sowa
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Krakow, Poland
| | - Krzysztof Tokarski
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Krakow, Poland
| | - Grzegorz Hess
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Krakow, Poland
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16
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Tang GB, Mi TW, Sun ML, Xu YJ, Yang SG, Du HZ, Saijilafu, Teng ZQ, Gao J, Liu CM. Overexpression of serotonin receptor 5b expression rescues neuronal and behavioral deficits in a mouse model of Kabuki syndrome. IBRO Rep 2020; 9:138-146. [PMID: 32775759 PMCID: PMC7394843 DOI: 10.1016/j.ibror.2020.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 07/03/2020] [Indexed: 12/11/2022] Open
Abstract
5-hydroxytryptamine receptor 5B (5-HT5B) is a gene coding for a G protein-coupled receptor (GPCR) that plays key roles in several neurodevelopmental disorders. Our previous study showed that disruption of 5-HT5B induced by lysine (K)-specific demethylase 6A (Kdm6a, also known as Utx) conditional knockout (cKO) in mouse hippocampus was associated with cognition deficits underlying intellectual disability in Kabuki syndrome (KS), a rare disease associated with multiple congenital and developmental abnormalities, especially neurobehavioral features. Here we show that Utx knockout (KO) in cultured hippocampal neurons leads to impaired neuronal excitability and calcium homeostasis. In addition, we show that 5-HT5B overexpression reverses dysregulation of neuronal excitability, intracellular calcium homeostasis, and long-term potentiation (LTP) in cultured Utx KO hippocampal neurons and hippocampal slices. More importantly, overexpression of 5-HT5B in Utx cKO mice results in reversal of abnormal anxiety-like behaviors and impaired spatial memory ability. Our findings therefore indicate that 5-HT5B, as a downstream target of Utx, functions to modulate electrophysiological outcomes, thereby affecting behavioral activities in KS mouse models.
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Affiliation(s)
- Gang-Bin Tang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Institute of Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ting-Wei Mi
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Institute of Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Man-Lian Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ya-Jie Xu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute of Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shu-Guang Yang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Institute of Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hong-Zhen Du
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Institute of Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Saijilafu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Orthopedic Institute, Soochow University, Suzhou, Jiangsu, China
| | - Zhao-Qian Teng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute of Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun Gao
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medicine Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Chang-Mei Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute of Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
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17
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Tanaka S, Tomita I, Seki S, Yamada S, Kogo M, Furusawa K. Serotonergic modulation of slow inward rectification in mesencephalic trigeminal neurons. Brain Res 2019; 1718:126-136. [PMID: 31085157 DOI: 10.1016/j.brainres.2019.05.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/23/2019] [Accepted: 05/10/2019] [Indexed: 11/29/2022]
Abstract
Inward rectification in response to membrane hyperpolarization is a prominent feature of mesencephalic trigeminal (Mes V) neurons and the hyperpolarization-activated inward current (Ih), as the basis of this property, regulates the spike discharge characteristics and input frequency preference (resonance) in these neurons, suggesting that Ih modulation is an important regulator of oral motor activity. To examine a possible contribution of serotonin (5-HT) to the modulation of Ih activation characteristics, in the present study, we investigated the modulatory effects of 5-HT receptor activation on Ih in postnatal day (P) 2-12 rat Mes V neurons by whole-cell patch-clamp recording. Bath application of 5-HT suppressed the Ih-dependent voltage sag and Ih conductance, but induced only a modest shift in the voltage dependence of Ih activation. This 5-HT-induced suppression of Ih was greater in P10-12 than P2-4 neurons, and involved the cAMP/protein kinase A (PKA) signaling pathway but not the PKC pathway. Pharmacological activation of the 5-HT1A receptor mimicked the effect of 5-HT, while modulation of other receptor subtypes, including 5-HT1B,1D, 5-HT2, and 5-HT3, had little or no effect on Ih. Low-frequency (<10 Hz) resonance at membrane potentials below the resting potential were reduced by 5-HT, suggesting that serotonergic Ih modulation can substantially alter the frequency preference to synaptic inputs. These results suggest that changes in resonance properties through serotonergic modulation of Ih may tune the firing of Mes V neurons to different afferent input frequencies and alter motor outputs to the jaw, thereby regulating oral motor activity.
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Affiliation(s)
- Susumu Tanaka
- Department of Oral and Maxillofacial Surgery, Matsumoto Dental University School of Dentistry, Shiojiri, Nagano 399-0781, Japan; The 1st Department of Oral and Maxillofacial Surgery, Osaka University, Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
| | - Ikuo Tomita
- Department of Oral and Maxillofacial Surgery, Matsumoto Dental University School of Dentistry, Shiojiri, Nagano 399-0781, Japan
| | - Soju Seki
- The 1st Department of Oral and Maxillofacial Surgery, Osaka University, Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Saori Yamada
- The 1st Department of Oral and Maxillofacial Surgery, Osaka University, Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
| | - Mikihiko Kogo
- The 1st Department of Oral and Maxillofacial Surgery, Osaka University, Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
| | - Kiyofumi Furusawa
- Department of Oral and Maxillofacial Surgery, Matsumoto Dental University School of Dentistry, Shiojiri, Nagano 399-0781, Japan
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18
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Zhao Y, Bijlsma EY, ter Heegde F, Verdouw MP, Garssen J, Newman-Tancredi A, Groenink L. Activation of somatodendritic 5-HT 1A autoreceptors reduces the acquisition and expression of cued fear in the rat fear-potentiated startle test. Psychopharmacology (Berl) 2019; 236:1171-1185. [PMID: 30539269 PMCID: PMC6591185 DOI: 10.1007/s00213-018-5124-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 11/14/2018] [Indexed: 11/29/2022]
Abstract
RATIONALE Fear conditioning is an important factor in the etiology of anxiety disorders. Previous studies have demonstrated a role for serotonin (5-HT)1A receptors in fear conditioning. However, the relative contribution of somatodendritic 5-HT1A autoreceptors and post-synaptic 5-HT1A heteroreceptors in fear conditioning is still unclear. OBJECTIVE To determine the role of pre- and post-synaptic 5-HT1A receptors in the acquisition and expression of cued and contextual conditioned fear. METHODS We studied the acute effects of four 5-HT1A receptor ligands in the fear-potentiated startle test. Male Wistar rats were injected with the 5-HT1A receptors biased agonists F13714 (0-0.16 mg/kg, IP), which preferentially activates somatodendritic 5-HT1A autoreceptors, or F15599 (0-0.16 mg/kg, IP), which preferentially activates cortical post-synaptic 5-HT1A heteroreceptors, with the prototypical 5-HT1A receptor agonist R(+)8-OH-DPAT (0-0.3 mg/kg, SC) or the 5-HT1A receptor antagonist WAY100,635 (0-1.0 mg/kg, SC). RESULTS F13714 (0.16 mg/kg) and R(+)-8-OH-DPAT (0.03 mg/kg) injected before training reduced cued fear acquisition. Pre-treatment with F15599 or WAY100,635 had no effect on fear learning. In the fear-potentiated startle test, F13714 (0.04-0.16 mg/kg) and R(+)-8-OH-DPAT (0.1-0.3 mg/kg) reduced the expression of cued and contextual fear, whereas F15599 had no effect. WAY100,635 (0.03-1.0 mg/kg) reduced the overall startle response. CONCLUSIONS The current findings indicate that activation of somatodendritic 5-HT1A autoreceptors reduces cued fear learning, whereas 5-HT1A receptors seem not involved in contextual fear learning. Moreover, activation of somatodendritic 5-HT1A autoreceptors may reduce cued and contextual fear expression, whereas we found no evidence for the involvement of cortical 5-HT1A heteroreceptors in the expression of conditioned fear.
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Affiliation(s)
- Yulong Zhao
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Elisabeth Y. Bijlsma
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Freija ter Heegde
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Monika P. Verdouw
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - J. Garssen
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | | | - Lucianne Groenink
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences (UIPS), Faculty of Science, Utrecht University, Utrecht, The Netherlands. .,Brain Center Rudolf Magnus (BCRM), UMC Utrecht, Utrecht, The Netherlands.
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Cortes-Altamirano JL, Olmos-Hernandez A, Jaime HB, Carrillo-Mora P, Bandala C, Reyes-Long S, Alfaro-Rodríguez A. Review: 5-HT1, 5-HT2, 5-HT3 and 5-HT7 Receptors and their Role in the Modulation of Pain Response in the Central Nervous System. Curr Neuropharmacol 2018; 16:210-221. [PMID: 28901281 PMCID: PMC5883380 DOI: 10.2174/1570159x15666170911121027] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 08/24/2017] [Accepted: 09/01/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The aim of this review was to identify the mechanisms by which serotonin receptors involved at the central level are able to modulate the nociceptive response. Pain is a defense mechanism of the body that entails physiological, anatomical, neurochemical, and psychological changes, and is defined as an unpleasant sensory and emotional experience with potential risk of tissue damage, comprising the leading cause of appointments with Physicians worldwide. Treatment for this symptom has generated several neuropharmacological lines of research, due to the different types of pain and the various drugs employed to treat this condition. Serotonin [5- HydroxyTryptamine (5-HT)] is a neurotransmitter with seven families (5-HT1-5-HT7) and approximately 15 receptor subtypes. Serotonin modulates neuronal activity; however, this neurotransmitter is related with a number of physiological processes, such as cardiovascular function, gastric motility, renal function, etc. On the other hand, several researches reported that serotonin modulates nociceptive response through 5-HT1, 5-HT2, 5-HT3, and 5-HT7 receptors in the Central Nervous System (CNS). METHOD In this review, a search was conducted on PubMed, ProQuest, EBSCO, and the Science Citation Index for studies evaluating the effects of 5-HT1, 5-HT2, 5-HT3, and 5-HT7 receptors in the CNS on the modulation of different types of pain. CONCLUSION We concluded that 5-HT1, 5-HT2, 5-HT3, and 5-HT7 receptors in the CNS modulate the pain, but this depends on the distribution of the receptors, dose of agonists or antagonists, administration route, pain type and duration in order to inhibit, excite, or even maintain the nociceptive response.
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Affiliation(s)
- Jose Luis Cortes-Altamirano
- PhD Program in Biological and Health Sciences, Universidad Autonoma Metropolitana Iztapalapa-Xochimilco- Cuajimalpa, Mexico, Calzada del Hueso 1100, Col. Villa Quietud, Mexico, D.F. 04960, Mexico
| | - Adriana Olmos-Hernandez
- Departament of Neurosciences, Instituto Nacional de Rehabilitacion, "Luis Guillermo Ibarra Ibarra", Secretaria de Salud, Col. Arenal de Guadalupe, Mexico, D.F. 14389, Mexico
| | - Herlinda Bonilla Jaime
- Departament of Reproductive Biology, Universidad Autonoma Metropolitana Campus Iztapalapa, Mexico, D.F. 09340, Mexico
| | - Paul Carrillo-Mora
- Departament of Neurosciences, Instituto Nacional de Rehabilitacion, "Luis Guillermo Ibarra Ibarra", Secretaria de Salud, Col. Arenal de Guadalupe, Mexico, D.F. 14389, Mexico
| | - Cindy Bandala
- Departament of Neurosciences, Instituto Nacional de Rehabilitacion, "Luis Guillermo Ibarra Ibarra", Secretaria de Salud, Col. Arenal de Guadalupe, Mexico, D.F. 14389, Mexico
| | - Samuel Reyes-Long
- Departament of Neurosciences, Instituto Nacional de Rehabilitacion, "Luis Guillermo Ibarra Ibarra", Secretaria de Salud, Col. Arenal de Guadalupe, Mexico, D.F. 14389, Mexico
| | - Alfonso Alfaro-Rodríguez
- Departament of Neurosciences, Instituto Nacional de Rehabilitacion, "Luis Guillermo Ibarra Ibarra", Secretaria de Salud, Col. Arenal de Guadalupe, Mexico, D.F. 14389, Mexico
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20
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The effect of chronic stimulation of serotonin receptor type 7 on recognition, passive avoidance memory, hippocampal long-term potentiation, and neuronal apoptosis in the amyloid β protein treated rat. Psychopharmacology (Berl) 2018; 235:1513-1525. [PMID: 29637287 DOI: 10.1007/s00213-018-4862-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 02/15/2018] [Indexed: 12/20/2022]
Abstract
RATIONALE Alzheimer's disease (AD) is a neurodegenerative disorder characterized by memory impairment, neuronal death, and synaptic loss in the hippocampus. Long-term potentiation (LTP), a type of synaptic plasticity, occurs during learning and memory. Serotonin receptor type 7 (5-HTR7) activation is suggested as a possible therapeutic target for AD. OBJECTIVE The aim of the present study was to examine the effects of chronic treatment with the 5-HTR7 agonist, AS19, on cognitive function, memory, hippocampal plasticity, amyloid beta (Aβ) plaque accumulation, and apoptosis in an adult rat model of AD. METHODS AD was induced in rats using Aβ (single 1 μg/μL intracerebroventricular (icv) injection during surgery). The following experimental groups were included: control, sham-operated, Aβ + saline (1 μL icv for 30 days), and Aβ + AS19 (1 μg/μL icv for 30 days) groups. The animals were tested for cognition and memory performance using the novel object recognition and passive avoidance tests, respectively. Next, anesthetized rats were placed in a stereotaxic apparatus for electrode implantation, and field potentials were recorded in the hippocampal dentate gyrus. Lastly, brains were removed and Aβ plaques and neuronal apoptosis were evaluated using Congo red staining and TUNEL assay, respectively. RESULTS Administration of AS19 in the Aβ rats increased the discrimination index of the novel object recognition test. Furthermore, AS19 treatment decreased time spent in the dark compartment during the passive avoidance test. AS19 also enhanced both the population spike (PS) amplitude and the field excitatory postsynaptic potential (fEPSP) slope evoked potentials of the LTP components. Aβ plaques and neuronal apoptosis were decreased in the AS19-treated Aβ rats. CONCLUSIONS These results indicate that chronic treatment with a 5-HTR7 agonist can prevent Aβ-related impairments in cognition and memory performance by alleviating Aβ plaque accumulation and neuronal apoptosis, hence improving neuronal plasticity. AS19 may be useful as a therapeutic agent for AD.
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21
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Sowa J, Kusek M, Siwiec M, Sowa JE, Bobula B, Tokarski K, Hess G. The 5-HT 7 receptor antagonist SB 269970 ameliorates corticosterone-induced alterations in 5-HT 7 receptor-mediated modulation of GABAergic transmission in the rat dorsal raphe nucleus. Psychopharmacology (Berl) 2018; 235:3381-3390. [PMID: 30267130 PMCID: PMC6267141 DOI: 10.1007/s00213-018-5045-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/19/2018] [Indexed: 11/29/2022]
Abstract
RATIONALE Chronic stress and corticosterone have been shown to affect serotonin (5-HT) neurotransmission; however, the influence of stress on the activity of the dorsal raphe nucleus (DRN), the main source of 5-HT in the forebrain, is not well understood. In particular, it is unknown if and how stress modifies DRN 5-HT7 receptors, which are involved in the modulation of the firing of local inhibitory interneurons responsible for regulating the activity of DRN projection cells. OBJECTIVES Our study aimed to investigate the effect of repeated corticosterone injections on the modulation of the inhibitory transmission within the DRN by 5-HT7 receptors and whether it could be reversed by treatment with a 5-HT7 receptor antagonist. METHODS Male Wistar rats received corticosterone injections repeated twice daily for 14 days. Spontaneous inhibitory postsynaptic currents (sIPSCs) were then recorded from DRN projection cells in ex vivo slice preparations obtained 24 h after the last injection. RESULTS Repeated corticosterone administration resulted in decreased frequency, but not amplitude, of sIPSCs in DRN projection cells. There were no changes in the excitability of these cells; however, corticosterone treatment suppressed the 5-HT7 receptor-mediated increase in sIPSC frequency. Administration of the 5-HT7 receptor antagonist SB 269970 for 7 days beginning on the eighth day of corticosterone treatment reversed the detrimental effects of corticosterone on 5-HT7 receptor reactivity and GABAergic transmission in the DRN. CONCLUSIONS Elevated corticosterone level reduces DRN 5HT7 receptor reactivity and decreases GABAergic transmission within the DRN, which can be reversed by the 5-HT7 receptor antagonist SB 269970.
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Affiliation(s)
- Joanna Sowa
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland
| | - Magdalena Kusek
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland
| | - Marcin Siwiec
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland
| | - Joanna Ewa Sowa
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland
| | - Bartosz Bobula
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland
| | - Krzysztof Tokarski
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland
| | - Grzegorz Hess
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland.
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The effects of the 5-HT7 receptor on hippocampal long-term potentiation and apoptosis in a rat model of Alzheimer’s disease. Brain Res Bull 2017; 135:85-91. [DOI: 10.1016/j.brainresbull.2017.10.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 10/01/2017] [Accepted: 10/03/2017] [Indexed: 12/29/2022]
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Zhou QG, Lee D, Ro EJ, Suh H. Regional-specific effect of fluoxetine on rapidly dividing progenitors along the dorsoventral axis of the hippocampus. Sci Rep 2016; 6:35572. [PMID: 27759049 PMCID: PMC5069667 DOI: 10.1038/srep35572] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 10/03/2016] [Indexed: 01/08/2023] Open
Abstract
Hippocampus-dependent cognitive and emotional function appears to be regionally dissociated along the dorsoventral (DV) axis of the hippocampus. Recent observations that adult hippocampal neurogenesis plays a critical role in both cognition and emotion raised an interesting question whether adult neurogenesis within specific subregions of the hippocampus contributes to these distinct functions. We examined the regional-specific and cell type-specific effects of fluoxetine, which requires adult hippocampal neurogenesis to function as an antidepressant, on the proliferation of hippocampal neural stem cells (NSCs). Fluoxetine specifically increased proliferation of NSCs located in the ventral region of the hippocampus while the mitotic index of NSCs in the dorsal portion of the hippocampus remained unaltered. Moreover, within the ventral hippocampus, type II NSC and neuroblast populations specifically responded to fluoxetine, showing increased proliferation; however, proliferation of type I NSCs was unchanged in response to fluoxetine. Activation or inhibition of serotonin receptor 1A (5-HTR1A) recapitulated or abolished the effect of fluoxetine on proliferation of type II NSCs and neuroblast populations in the ventral hippocampus. Our study showed that the effect of fluoxetine on proliferation is dependent upon the type and the position of the NSCs along the DV axis of the hippocampus.
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Affiliation(s)
- Qi-Gang Zhou
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Institution of Stem Cells and Neuroregeneration, Department of Pharmacology, Pharmacy College, Nanjing Medical University, Nanjing, P.R. China
| | - Daehoon Lee
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Eun Jeoung Ro
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Hoonkyo Suh
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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Morton RA, Valenzuela CF. Third Trimester Equivalent Alcohol Exposure Reduces Modulation of Glutamatergic Synaptic Transmission by 5-HT1A Receptors in the Rat Hippocampal CA3 Region. Front Neurosci 2016; 10:266. [PMID: 27375424 PMCID: PMC4896948 DOI: 10.3389/fnins.2016.00266] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/26/2016] [Indexed: 01/05/2023] Open
Abstract
Fetal alcohol exposure has been associated with many neuropsychiatric disorders that have been linked to altered serotonin (5-hydroxytryptamine; 5-HT) signaling, including depression and anxiety. During the first 2 weeks of postnatal life in rodents (equivalent to the third trimester of human pregnancy) 5-HT neurons undergo significant functional maturation and their axons reach target regions in the forebrain (e.g., cortex and hippocampus). The objective of this study was to identify the effects of third trimester ethanol (EtOH) exposure on hippocampal 5-HT signaling. Using EtOH vapor inhalation chambers, we exposed rat pups to EtOH for 4 h/day from postnatal day (P) 2 to P12. The average serum EtOH concentration in the pups was 0.13 ± 0.04 g/dl (legal intoxication limit in humans = 0.08 g/dl). We used brain slices to assess the modulatory actions of 5-HT on field excitatory postsynaptic potentials in the hippocampal CA3 region at P13-P15. Application of the GABAA/glycine receptor antagonist, picrotoxin, caused broadening of field excitatory postsynaptic potentials (fEPSPs), an effect that was reversed by application of 5-HT in slices from air exposed rats. However, this effect of 5-HT was absent in EtOH exposed animals. In slices from naïve animals, application of a 5-HT1A receptor antagonist blocked the effect of 5-HT on the fEPSPs recorded in presence of picrotoxin, suggesting that third trimester ethanol exposure acts by inhibiting the function of these receptors. Studies indicate that 5-HT1A receptors play a critical role in the development of hippocampal circuits. Therefore, inhibition of these receptors by third trimester ethanol exposure could contribute to the pathophysiology of fetal alcohol spectrum disorders.
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Affiliation(s)
- Russell A Morton
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA
| | - C Fernando Valenzuela
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center Albuquerque, NM, USA
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25
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Andreetta F, Carboni L, Grafton G, Jeggo R, Whyment AD, van den Top M, Hoyer D, Spanswick D, Barnes NM. Hippocampal 5-HT7 receptors signal phosphorylation of the GluA1 subunit to facilitate AMPA receptor mediated-neurotransmission in vitro and in vivo. Br J Pharmacol 2016; 173:1438-51. [PMID: 26773257 PMCID: PMC4831309 DOI: 10.1111/bph.13432] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/21/2015] [Accepted: 01/12/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE The 5-HT7 receptor is a GPCR that is the target of a broad range of antidepressant and antipsychotic drugs. Various studies have demonstrated an ability of the 5-HT7 receptor to modulate glutamatergic neurotransmission and cognitive processes although the potential impact upon AMPA receptors has not been investigated directly. The purposes of the present study were to investigate a direct modulation of the GluA1 AMPA receptor subunit and determine how this might influence AMPA receptor function. EXPERIMENTAL APPROACH The influence of pharmacological manipulation of the 5-HT7 receptor system upon phosphorylation of GluA1 subunits was assessed by Western blotting of fractionated proteins from hippocampal neurones in culture (or proteins resident at the neurone surface) and the functional impact assessed by electrophysiological recordings in rat hippocampus in vitro and in vivo. KEY RESULTS 5-HT7 receptor activation increased cAMP and relative pCREB levels in cultures of rat hippocampal neurones along with an increase in phosphorylation (Ser845) of the GluA1 AMPA receptor subunit evident in whole neurone extracts and within the neurone surface compartment. Electrophysiological recordings in rat hippocampus demonstrated a 5-HT7 receptor-mediated increase in AMPA receptor-mediated neurotransmission in vitro and in vivo. CONCLUSIONS AND IMPLICATIONS The 5-HT7 receptor-mediated phosphorylation of the GluA1 AMPA receptor provides a molecular mechanism consistent with the 5-HT7 receptor-mediated increase in AMPA receptor-mediated neurotransmission.
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Affiliation(s)
- Filippo Andreetta
- Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
- Neurosciences CEDD, GlaxoSmithKline Medicine Research Centre, Verona, Italy
| | - Lucia Carboni
- Neurosciences CEDD, GlaxoSmithKline Medicine Research Centre, Verona, Italy
| | - Gillian Grafton
- Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | | | | | | | - Daniel Hoyer
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Vic., Australia
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia
- Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | | | - Nicholas M Barnes
- Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Vic., Australia
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Orsolini L, Tomasetti C, Valchera A, Iasevoli F, Buonaguro EF, Vellante F, Fornaro M, Fiengo A, Mazza M, Vecchiotti R, Perna G, de Bartolomeis A, Martinotti G, Di Giannantonio M, De Berardis D. New advances in the treatment of generalized anxiety disorder: the multimodal antidepressant vortioxetine. Expert Rev Neurother 2016; 16:483-95. [PMID: 27050932 DOI: 10.1586/14737175.2016.1173545] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Generalized Anxiety Disorder (GAD) is a persistent condition characterized by chronic anxiety, exaggerated worry and tension, mainly comorbid with Major Depressive Disorder (MDD). Currently, selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors are recommended as first-line treatment of GAD. However, some patients may not respond to the treatment or discontinue due to adverse effects. Vortioxetine (VRX) is a multimodal antidepressant with a unique mechanism of action, by acting as 5-HT3A, 5-HT1D and 5-HT7 receptor antagonist, partial agonist at the 5-HT1A and 5-HT1B receptors and inhibitor at the 5-HT transporter. Preliminary clinical trials showed contrasting findings in terms of improvement of the anxiety symptomatology and/or cognitive impairment. Here, we aim to systematically review the evidence currently available on the efficacy, safety and tolerability of VRX in the treatment of GAD. The generalizability of results on the efficacy of VRX in patients with anxiety symptomatology and GAD is limited due to few and contrasting RCTs so far available. Only two studies, of which one prevention relapse trial, reported a significant improvement in anxiety symptomatology compared to three with negative findings.
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Affiliation(s)
- Laura Orsolini
- a School of Life and Medical Sciences , University of Hertfordshire , Hatfield , UK.,b Villa San Giuseppe Hospital , Hermanas Hospitalarias , Ascoli Piceno , Italy.,c Polyedra Research Group , Teramo , Italy.,d Department of Psychiatry and Neuropsychology , University of Maastricht , Maastricht , The Netherlands
| | - Carmine Tomasetti
- c Polyedra Research Group , Teramo , Italy.,e NHS, Department of Mental Health ASL Teramo, Psychiatric Service of Diagnosis and Treatment , Hospital 'Maria SS dello Splendore' , Giulianova , Italy.,f Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, Reproductive and Odontostomatogical Sciences , University of Naples 'Federico II' , Napoli , Italy
| | - Alessandro Valchera
- b Villa San Giuseppe Hospital , Hermanas Hospitalarias , Ascoli Piceno , Italy.,c Polyedra Research Group , Teramo , Italy
| | - Felice Iasevoli
- c Polyedra Research Group , Teramo , Italy.,f Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, Reproductive and Odontostomatogical Sciences , University of Naples 'Federico II' , Napoli , Italy
| | - Elisabetta Filomena Buonaguro
- c Polyedra Research Group , Teramo , Italy.,f Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, Reproductive and Odontostomatogical Sciences , University of Naples 'Federico II' , Napoli , Italy
| | - Federica Vellante
- c Polyedra Research Group , Teramo , Italy.,g NHS, Department of Mental Health ASL Teramo, Psychiatric Service of Diagnosis and Treatment , Hospital 'G. Mazzini' , Teramo , Italy.,h Department of Neuroscience and Imaging , University 'G. d'Annunzio' , Chieti , Italy
| | - Michele Fornaro
- c Polyedra Research Group , Teramo , Italy.,i New York Psychiatric Institute , Columbia University , New York , NY , USA
| | | | - Monica Mazza
- c Polyedra Research Group , Teramo , Italy.,j Department of Life, Health and Environmental Sciences , University of L'Aquila , L'Aquila , Italy
| | - Roberta Vecchiotti
- b Villa San Giuseppe Hospital , Hermanas Hospitalarias , Ascoli Piceno , Italy.,c Polyedra Research Group , Teramo , Italy.,d Department of Psychiatry and Neuropsychology , University of Maastricht , Maastricht , The Netherlands
| | - Giampaolo Perna
- d Department of Psychiatry and Neuropsychology , University of Maastricht , Maastricht , The Netherlands.,k Hermanas Hospitalarias, FoRiPsi, Department of Clinical Neurosciences , Villa San Benedetto Menni , Albese con Cassano , Como , Italy.,l Department of Psychiatry and Behavioral Sciences , Leonard Miller School of Medicine, University of Miami , Coral Gables , Florida , USA
| | - Andrea de Bartolomeis
- f Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, Reproductive and Odontostomatogical Sciences , University of Naples 'Federico II' , Napoli , Italy
| | - Giovanni Martinotti
- i New York Psychiatric Institute , Columbia University , New York , NY , USA
| | | | - Domenico De Berardis
- c Polyedra Research Group , Teramo , Italy.,g NHS, Department of Mental Health ASL Teramo, Psychiatric Service of Diagnosis and Treatment , Hospital 'G. Mazzini' , Teramo , Italy.,i New York Psychiatric Institute , Columbia University , New York , NY , USA
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27
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Balakrishnan S, Niebert M, Richter DW. Rescue of Cyclic AMP Mediated Long Term Potentiation Impairment in the Hippocampus of Mecp2 Knockout (Mecp2(-/y) ) Mice by Rolipram. Front Cell Neurosci 2016; 10:15. [PMID: 26869885 PMCID: PMC4737891 DOI: 10.3389/fncel.2016.00015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 01/15/2016] [Indexed: 11/13/2022] Open
Abstract
Rett syndrome (RTT) patients experience learning difficulties and memory loss. Analogous deficits of hippocampal plasticity are reported in mouse models of RTT. To elucidate the underlying pathophysiology, we studied long term potentiation (LTP) at the CA3 to CA1 synapses in the hippocampus in acute brain slices from WT and Mecp2(-/y) mice, by either activating cAMP dependent pathway or using high frequency stimulation, by means of patch clamp. We have observed that, the NMDA channel current characteristics remain unchanged in the Mecp2(-/y) mice. The adenylyl cyclase (AC) agonist forskolin evoked a long lasting potentiation of evoked EPSCs in WT CA1 neurons, but only minimally enhanced the EPSCs in the Mecp2(-/y) mice. This weaker potentiation in Mecp2 (-/) (y) mice was ameliorated by application of phosphodiesterase 4 inhibitor rolipram. The hyperpolarization activated cyclic nucleotide gated channel current (I h) was potentiated to similar extent by forskolin in both phenotypes. Multiple tetanus induced cAMP-dependent plasticity was also impaired in the Mecp2 (-/) (y) mice, and was also partially rescued by rolipram. Western blot analysis of CA region of Mecp2 (-/) (y) mice hippocampus revealed more than twofold up-regulation of protein kinase A (PKA) regulatory subunits, while the expression of the catalytic subunit remained unchanged. We hypothesize that the overexpressed PKA regulatory subunits buffer cAMP and restrict the PKA mediated phosphorylation of target proteins necessary for LTP. Blocking the degradation of cAMP, thereby saturating the regulatory subunits alleviated this defect.
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Affiliation(s)
- Saju Balakrishnan
- Institute for Neuro and Sensory Physiology, University of Göttingen Göttingen, Germany
| | - Marcus Niebert
- Institute for Neuro and Sensory Physiology, University of Göttingen Göttingen, Germany
| | - Diethelm W Richter
- Institute for Neuro and Sensory Physiology, University of Göttingen Göttingen, Germany
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Ohno Y, Shimizu S, Tokudome K, Kunisawa N, Sasa M. New insight into the therapeutic role of the serotonergic system in Parkinson's disease. Prog Neurobiol 2015; 134:104-21. [DOI: 10.1016/j.pneurobio.2015.09.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 08/17/2015] [Accepted: 09/05/2015] [Indexed: 11/30/2022]
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29
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Zhang QJ, Du CX, Tan HH, Zhang L, Li LB, Zhang J, Niu XL, Liu J. Activation and blockade of serotonin7 receptors in the prelimbic cortex regulate depressive-like behaviors in a 6-hydroxydopamine-induced Parkinson's disease rat model. Neuroscience 2015; 311:45-55. [PMID: 26470809 DOI: 10.1016/j.neuroscience.2015.10.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/16/2015] [Accepted: 10/08/2015] [Indexed: 01/27/2023]
Abstract
The role of serotonin7 (5-HT7) receptors in the regulation of depression is poorly understood, particularly in Parkinson's disease-associated depression. Here we examined whether 5-HT7 receptors in the prelimbic (PrL) sub-region of the ventral medial prefrontal cortex (mPFC) involve in the regulation of depressive-like behaviors in sham-operated rats and rats with unilateral 6-hydroxydopamine lesions of the medial forebrain bundle. The lesion induced depressive-like responses as measured by the sucrose preference and forced swim tests when compared to sham-operated rats. Intra-PrL injection of 5-HT7 receptor agonist AS19 (0.5, 1 and 2 μg/rat) increased sucrose consumption, and decreased immobility time in sham-operated and the lesioned rats, indicating the induction of antidepressant-like effects. Further, intra-PrL injection of 5-HT7 receptor antagonist SB269970 (1.5, 3 and 6 μg/rat) decreased sucrose consumption, and increased immobility time, indicating the induction of depressive-like responses. However, the doses producing these effects in the lesioned rats were higher than those in sham-operated rats. Neurochemical results showed that intra-PrL injection of AS19 (2 μg/rat) increased dopamine, 5-hydroxytryptamine (5-HT) and noradrenaline (NA) levels in the mPFC, habenula and ventral hippocampus (vHip) in sham-operated and the lesioned rats; whereas SB269970 (6 μg/rat) decreased 5-HT levels in the habenula and vHip, and the levels of NA in the mPFC, habenula and vHip in the two groups of rats. The results suggest that 5-HT7 receptors in the PrL play an important role in the regulation of these behaviors, which attribute to changes in monoamine levels in the limbic and limbic-related brain regions after activation and blockade of 5-HT7 receptors.
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Affiliation(s)
- Q J Zhang
- Department of Rehabilitation Medicine, The Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China
| | - C X Du
- Department of Rehabilitation Medicine, The Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China
| | - H H Tan
- Department of Rehabilitation Medicine, The Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China
| | - L Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - L B Li
- Department of Rehabilitation Medicine, The Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China
| | - J Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - X L Niu
- Department of Medicine, The Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China
| | - J Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
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Kusek M, Sowa J, Kamińska K, Gołembiowska K, Tokarski K, Hess G. 5-HT7 receptor modulates GABAergic transmission in the rat dorsal raphe nucleus and controls cortical release of serotonin. Front Cell Neurosci 2015; 9:324. [PMID: 26347612 PMCID: PMC4539517 DOI: 10.3389/fncel.2015.00324] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/05/2015] [Indexed: 01/17/2023] Open
Abstract
The 5-HT7 receptor is one of the several serotonin (5-HT) receptor subtypes that are expressed in the dorsal raphe nucleus (DRN). Some earlier findings suggested that 5-HT7 receptors in the DRN were localized on GABAergic interneurons modulating the activity of 5-HT projection neurons. The aim of the present study was to find out how the 5-HT7 receptor modulates the GABAergic synaptic input to putative 5-HT DRN neurons, and whether blockade of the 5-HT7 receptor would affect the release of 5-HT in the target structure. Male Wistar rats with microdialysis probes implanted in the prefrontal cortex (PFC) received injections of the 5-HT7 receptor antagonist (2R)-1-[(3-hydroxyphenyl)sulfonyl]-2-[2-(4-methyl-1-piperidinyl)ethyl]pyrrolidine hydrochloride (SB 269970), which induced an increase in the levels of 5-HT and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA) in the PFC. In another set of experiments whole-cell recordings from presumed projection neurons were carried out using DRN slices. SB 269970 application resulted in depolarization and in an increase in the firing frequency of the cells. In order to activate 5-HT7 receptors, 5-carboxamidotryptamine (5-CT) was applied in the presence of N-[2-[4-(2-methoxyphenyl)-1piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY100635). Hyperpolarization of cells and a decrease in the firing frequency were observed after activation of the 5-HT7 receptor. Blockade of 5-HT7 receptors caused a decrease in the mean frequency of spontaneous inhibitory postsynaptic currents (sIPSCs), while its activation induced an increase. The mechanism of these effects appears to involve tonically-active 5-HT7 receptors modulating firing and/or GABA release from inhibitory interneurons which regulate the activity of DRN serotonergic projection neurons.
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Affiliation(s)
- Magdalena Kusek
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Joanna Sowa
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Katarzyna Kamińska
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Krystyna Gołembiowska
- Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Krzysztof Tokarski
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland
| | - Grzegorz Hess
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences Krakow, Poland ; Institute of Zoology, Jagiellonian University Krakow, Poland
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31
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Stiedl O, Pappa E, Konradsson-Geuken Å, Ögren SO. The role of the serotonin receptor subtypes 5-HT1A and 5-HT7 and its interaction in emotional learning and memory. Front Pharmacol 2015; 6:162. [PMID: 26300776 PMCID: PMC4528280 DOI: 10.3389/fphar.2015.00162] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 07/20/2015] [Indexed: 11/13/2022] Open
Abstract
Serotonin [5-hydroxytryptamine (5-HT)] is a multifunctional neurotransmitter innervating cortical and limbic areas involved in cognition and emotional regulation. Dysregulation of serotonergic transmission is associated with emotional and cognitive deficits in psychiatric patients and animal models. Drugs targeting the 5-HT system are widely used to treat mood disorders and anxiety-like behaviors. Among the fourteen 5-HT receptor (5-HTR) subtypes, the 5-HT1AR and 5-HT7R are associated with the development of anxiety, depression and cognitive function linked to mechanisms of emotional learning and memory. In rodents fear conditioning and passive avoidance (PA) are associative learning paradigms to study emotional memory. This review assesses the role of 5-HT1AR and 5-HT7R as well as their interplay at the molecular, neurochemical and behavioral level. Activation of postsynaptic 5-HT1ARs impairs emotional memory through attenuation of neuronal activity, whereas presynaptic 5-HT1AR activation reduces 5-HT release and exerts pro-cognitive effects on PA retention. Antagonism of the 5-HT1AR facilitates memory retention possibly via 5-HT7R activation and evidence is provided that 5HT7R can facilitate emotional memory upon reduced 5-HT1AR transmission. These findings highlight the differential role of these 5-HTRs in cognitive/emotional domains of behavior. Moreover, the results indicate that tonic and phasic 5-HT release can exert different and potentially opposing effects on emotional memory, depending on the states of 5-HT1ARs and 5-HT7Rs and their interaction. Consequently, individual differences due to genetic and/or epigenetic mechanisms play an essential role for the responsiveness to drug treatment, e.g., by SSRIs which increase intrasynaptic 5-HT levels thereby activating multiple pre- and postsynaptic 5-HTR subtypes.
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Affiliation(s)
- Oliver Stiedl
- Department of Functional Genomics, Behavioral Neuroscience Group, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam - VU University Amsterdam Amsterdam, Netherlands ; Department of Molecular and Cellular Neurobiology, Behavioral Neuroscience Group, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam -VU University Amsterdam Amsterdam, Netherlands
| | - Elpiniki Pappa
- Department of Functional Genomics, Behavioral Neuroscience Group, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam - VU University Amsterdam Amsterdam, Netherlands ; Department of Molecular and Cellular Neurobiology, Behavioral Neuroscience Group, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam -VU University Amsterdam Amsterdam, Netherlands
| | | | - Sven Ove Ögren
- Department of Neuroscience, Karolinska Institutet Stockholm, Sweden
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Pittalà V, Siracusa MA, Salerno L, Romeo G, Modica MN, Madjid N, Ogren SO. Analysis of mechanisms for memory enhancement using novel and potent 5-HT1A receptor ligands. Eur Neuropsychopharmacol 2015; 25:1314-23. [PMID: 25963581 DOI: 10.1016/j.euroneuro.2015.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 04/15/2015] [Accepted: 04/21/2015] [Indexed: 11/28/2022]
Abstract
In light of the involvement of serotonergic 5-HT1A receptors in the mediation of the memory of aversive events, the potent and selective 5-HT1A receptor antagonists, MC18 fumarate and VP08/34 fumarate, were tested in the passive avoidance task (PA), a rodent model of instrumental conditioning. Either alone or in combination with the prototypical agonist 8-OH-DPAT, MC18 fumarate at doses (0.1, 0.3 and 1mg/kg given 15min prior to training) exerted a dose-dependent facilitation of PA memory retention. When administered 15min prior to 8-OH-DPAT (0.3 and 1mg/kg), MC18 fumarate at a dose of 0.3mg/kg, enhanced significantly the impairment of PA retention caused by 8-OH-DPAT (1mg/kg). However, VP08/34 fumarate given at the same doses exerted no statistically effect on PA retention memory. Furthermore, VP08/34 fumarate given 15min prior to 8-OH-DPAT (0.3 and 1mg/kg) only slightly enhanced the PA impairment induced by 8-OH-DPAT. In conclusion, the profile of MC18 fumarate is intriguing since it behaves in a manner which differs from both full receptor antagonists such as NAD-299 or partial receptor agonists. The results also illustrate the importance of subtle receptor interaction and probably ligand efficacy in determining the actions of two almost identical 5-HT1A receptor ligands in cognitive function such as instrumental learning.
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Affiliation(s)
- Valeria Pittalà
- Department of Drug Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy.
| | - Maria A Siracusa
- Department of Drug Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Loredana Salerno
- Department of Drug Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Romeo
- Department of Drug Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Maria N Modica
- Department of Drug Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Nather Madjid
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE-171 77 Stockholm, Sweden
| | - Sven Ove Ogren
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, SE-171 77 Stockholm, Sweden.
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Andrews PW, Bharwani A, Lee KR, Fox M, Thomson JA. Is serotonin an upper or a downer? The evolution of the serotonergic system and its role in depression and the antidepressant response. Neurosci Biobehav Rev 2015; 51:164-88. [DOI: 10.1016/j.neubiorev.2015.01.018] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 01/08/2015] [Accepted: 01/15/2015] [Indexed: 12/17/2022]
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Ciranna L, Catania MV. 5-HT7 receptors as modulators of neuronal excitability, synaptic transmission and plasticity: physiological role and possible implications in autism spectrum disorders. Front Cell Neurosci 2014; 8:250. [PMID: 25221471 PMCID: PMC4145633 DOI: 10.3389/fncel.2014.00250] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/06/2014] [Indexed: 12/22/2022] Open
Abstract
Serotonin type 7 receptors (5-HT7) are expressed in several brain areas, regulate brain development, synaptic transmission and plasticity, and therefore are involved in various brain functions such as learning and memory. A number of studies suggest that 5-HT7 receptors could be potential pharmacotherapeutic target for cognitive disorders. Several abnormalities of serotonergic system have been described in patients with autism spectrum disorder (ASD), including abnormal activity of 5-HT transporter, altered blood and brain 5-HT levels, reduced 5-HT synthesis and altered expression of 5-HT receptors in the brain. A specific role for 5-HT7 receptors in ASD has not yet been demonstrated but some evidence implicates their possible involvement. We have recently shown that 5-HT7 receptor activation rescues hippocampal synaptic plasticity in a mouse model of Fragile X Syndrome, a monogenic cause of autism. Several other studies have shown that 5-HT7 receptors modulate behavioral flexibility, exploratory behavior, mood disorders and epilepsy, which include core and co-morbid symptoms of ASD. These findings further suggest an involvement of 5-HT7 receptors in ASD. Here, we review the physiological roles of 5-HT7 receptors and their implications in Fragile X Syndrome and other ASD.
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Affiliation(s)
- Lucia Ciranna
- Department of Biomedical Sciences, University of Catania Catania, Italy
| | - Maria Vincenza Catania
- Institute of Neurological Sciences, the National Research Council of Italy (CNR) Catania, Italy ; Laboratory of Neurobiology, IRCCS Oasi Maria SS Troina, Italy
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Youn J, Hager T, Misane I, Pieneman AW, Jansen RF, Ogren SO, Meyer M, Stiedl O. Central 5-HT1A receptor-mediated modulation of heart rate dynamics and its adjustment by conditioned and unconditioned fear in mice. Br J Pharmacol 2014; 170:859-70. [PMID: 23902597 DOI: 10.1111/bph.12325] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 07/11/2013] [Accepted: 07/24/2013] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE The beat-by-beat fluctuation (dynamics) of heart rate (HR) depends on centrally mediated control of the autonomic nervous system (ANS) reflecting the physiological state of an organism. 5-HT1A receptors are implicated in affective disorders,associated with ANS dysregulation which increases cardiac risk but their role in autonomic HR regulation under physiological conditions is insufficiently characterized. EXPERIMENTAL APPROACH The effects of subcutaneously administered 5-HT1A receptor ligands on HR dynamics were investigated in C57BL/6 mice during stress-free conditions and emotional challenge (recall of fear conditioned to an auditory stimulus and novelty exposure) using time domain and non-linear HR analyses. KEY RESULTS Pre-training treatment with of 8-OH-DPAT (0.5 mg·kg(-1) , s.c.) prevented conditioned tachycardia in the retention test indicating impaired fear memory. Pretest 5-HT1A receptor activation by 8-OH-DPAT (0.5 but not 0.1 and 0.02 mg·kg(-1) ) caused bradycardia and increased HR variability. 8-OH-DPAT (0.5 mg·kg(-1) ) lowered the unconditioned and conditioned tachycardia from ∼750 to ∼550 bpm, without changing the conditioned HR response to the sound. 8-OH-DPAT induced profound QT prolongation and bradyarrhythmic episodes. Non-linear analysis indicated a pathological state of HR dynamics after 8-OH-DPAT (0.5 mg·kg(-1) ) with ANS hyperactivation impairing HR adaptability. The 5-HT1A receptor antagonist WAY-100635 (0.03 mg·kg(-1) ) blocked these effects of 8-OH-DPAT. CONCLUSIONS AND IMPLICATIONS Pre-training 5-HT1A receptor activation by 8-OH-DPAT (0.5 mg·kg(-1) ) impaired memory of conditioned auditory fear based on an attenuated HR increase, whereas pretest administration did not prevent the fear-conditioned HR increase but induced pathological HR dynamics through central ANS dysregulation with cardiac effects similar to acute SSRI overdose.
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Affiliation(s)
- Jiun Youn
- Behavioral Neuroscience Group, Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Amsterdam, The Netherlands
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Hu L, Santoro B, Saponaro A, Liu H, Moroni A, Siegelbaum S. Binding of the auxiliary subunit TRIP8b to HCN channels shifts the mode of action of cAMP. ACTA ACUST UNITED AC 2014; 142:599-612. [PMID: 24277603 PMCID: PMC3840918 DOI: 10.1085/jgp.201311013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hyperpolarization-activated cyclic nucleotide–regulated cation (HCN) channels generate the hyperpolarization-activated cation current Ih present in many neurons. These channels are directly regulated by the binding of cAMP, which both shifts the voltage dependence of HCN channel opening to more positive potentials and increases maximal Ih at extreme negative voltages where voltage gating is complete. Here we report that the HCN channel brain-specific auxiliary subunit TRIP8b produces opposing actions on these two effects of cAMP. In the first action, TRIP8b inhibits the effect of cAMP to shift voltage gating, decreasing both the sensitivity of the channel to cAMP (K1/2) and the efficacy of cAMP (maximal voltage shift); conversely, cAMP binding inhibits these actions of TRIP8b. These mutually antagonistic actions are well described by a cyclic allosteric mechanism in which TRIP8b binding reduces the affinity of the channel for cAMP, with the affinity of the open state for cAMP being reduced to a greater extent than the cAMP affinity of the closed state. In a second apparently independent action, TRIP8b enhances the action of cAMP to increase maximal Ih. This latter effect cannot be explained by the cyclic allosteric model but results from a previously uncharacterized action of TRIP8b to reduce maximal current through the channel in the absence of cAMP. Because the binding of cAMP also antagonizes this second effect of TRIP8b, application of cAMP produces a larger increase in maximal Ih in the presence of TRIP8b than in its absence. These findings may provide a mechanistic explanation for the wide variability in the effects of modulatory transmitters on the voltage gating and maximal amplitude of Ih reported for different neurons in the brain.
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Affiliation(s)
- Lei Hu
- Department of Neuroscience, 2 Department of Pharmacology, and 3 Howard Hughes Medical Institute, Columbia University, New York, NY 10032
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Abstract
Monoamine-based treatments for depression have evolved greatly over the past several years, but shortcomings such as suboptimal efficacy, treatment lag, and residual cognitive dysfunction are still significant. Preclinical and clinical studies using compounds directly targeting glutamatergic neurotransmission present new opportunities for antidepressant treatment, with ketamine having a surprisingly rapid and sustained antidepressant effect that is presumably mediated through glutamate-dependent mechanisms. While direct modulation of glutamate transmission for antidepressant and cognition-enhancing actions may be hampered by nonspecific effects, indirect modulation through the serotonin (5-HT) system may be a viable alternative approach. Based on localization and function, 5-HT can modulate glutamate neurotransmission at least through the 5-HT1A, 5-HT1B, 5-HT3, and 5-HT7 receptors, which presents a rational pharmacological opportunity for modulating glutamatergic transmission without the direct use of glutamatergic compounds. Combining one or more of these glutamate-modulating 5-HT targets with 5-HT transporter inhibition may offer new therapeutic opportunities. The multimodal compounds vortioxetine and vilazodone are examples of this approach with diverse mechanisms, and their different clinical effects will provide valuable insights into serotonergic modulation of glutamate transmission for the potential treatment of depression and associated cognitive dysfunction.
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Distribution of Serotonin 4(a) Receptors in the juvenile Rat Brain and Spinal Cord. J Chem Neuroanat 2014; 55:67-77. [DOI: 10.1016/j.jchemneu.2013.12.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 12/30/2013] [Accepted: 12/30/2013] [Indexed: 11/23/2022]
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Tokarski K, Bobula B, Grzegorzewska-Hiczwa M, Kusek M, Hess G. Stress- and antidepressant treatment-induced modifications of 5-HT₇ receptor functions in the rat brain. Pharmacol Rep 2013; 64:1305-15. [PMID: 23406741 DOI: 10.1016/s1734-1140(12)70928-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 10/24/2012] [Indexed: 01/07/2023]
Abstract
This paper summarizes a series of electrophysiological studies aimed at finding the effects of the activation of 5-HT(7) receptors on neuronal excitability as well as on excitatory and inhibitory synaptic transmission in the hippocampus and in the frontal cortex of the rat. These studies demonstrated that 5-HT(7) receptors play an important role in the modulation of the activity of the hippocampal network by regulating the excitability of pyramidal cells of the CA1 area, as well as via their effect on GABA and glutamatergic transmission. The reactivity of 5-HT(7) receptors in the hippocampus is decreased by repeated administration of antidepressant drugs and increased by a prolonged high level of corticosterone. More importantly, administration of antidepressant drug, imipramine, prevents the occurrence of corticosterone-induced changes in the function of hippocampal 5-HT(7) receptors. It has also been found that the blockade of 5-HT(7) receptors by the selective antagonist SB 269970, lasting for a few days, causes similar changes to those observed after long-term administration of antidepressants. Thus, it seems that the pharmacological blockade of 5-HT(7) receptors produces faster effects compared to classic antidepressant drugs. A similarity between the changes in the glutamatergic transmission induced by the blockade of 5 HT7 receptors and those caused by repeated administration of the antidepressant drug, imipramine, has also been found in the frontal cortex. It has also been shown that the changes in glutamatergic transmission and the impairment of long-term synaptic plasticity in the frontal cortex of animals subjected to repeated restraint stress are reversed by the blockade of 5-HT(7) receptors. Overall, these studies, together with the data provided by other investigators, support the hypothesis that 5-HT(7) receptor antagonists may become a prototype of a new class of antidepressant drugs. Such compounds will not function by blocking 5-HT reuptake, as many of the currently used drugs, but through a direct interaction with the 5-HT(7) receptor. This type of action is highly selective and usually does not require the occurrence of adaptive changes in neuronal functions, thus allowing for a much quicker therapeutic effect.
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Affiliation(s)
- Krzysztof Tokarski
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, PL 31-343 Kraków, Poland.
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40
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Human 5-HT₄receptor stimulation in atria of transgenic mice. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:357-67. [PMID: 23307014 DOI: 10.1007/s00210-013-0831-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 01/01/2013] [Indexed: 01/08/2023]
Abstract
In human atrium, serotonin (5-HT) exerts pleiotropic effects, which are thought to be mediated via 5-HT4 receptors. Here, we used transgenic mice (TG) that overexpress the human 5-HT4(a) receptor under control of the heart-specific α-myosin heavy chain promoter in the atria (and ventricles). Contractile studies were performed in isolated electrically driven left atrial preparations and spontaneously beating right atrial preparation of TG and littermate control mice (wild type (WT)). 5-HT increased force of contraction and phospholamban phosphorylation on serine 16 only in left atrial preparations from TG but not from WT. In contrast, β-adrenoceptor stimulation of left atrial preparations by isoprenaline increased force of contraction with similar pEC50 values and to a similar maximum extent in both TG and WT. The contractile effects of 5-HT in left atrial preparations from TG could be blocked by the 5-HT4 receptor-specific antagonists GR125487 or GR113808. In right atrial preparations from WT and TG, the β-adrenoceptor agonist isoprenaline exerted a positive chronotropic effect with similar pEC50 values and similar maximum effects. Only in right atrial preparations from TG but not WT, 5-HT exerted a positive chronotropic effect that could be attenuated by 5-HT4 receptor-specific antagonists. Finally, in left atrial preparations of TG, a higher incidence of arrhythmias was noted compared to WT. The present data indicate that the human 5-HT4 receptors expressed in mouse atria are functional. This is the first transgenic model to study this human receptor in the atrium ex vivo or in vivo.
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Tokarski K, Zelek-Molik A, Duszyńska B, Satała G, Bobula B, Kusek M, Chmielarz P, Nalepa I, Hess G. Acute and repeated treatment with the 5-HT7 receptor antagonist SB 269970 induces functional desensitization of 5-HT7 receptors in rat hippocampus. Pharmacol Rep 2012; 64:256-65. [PMID: 22661174 DOI: 10.1016/s1734-1140(12)70763-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 03/22/2012] [Indexed: 01/01/2023]
Abstract
BACKGROUND SB 269970, a 5-HT(7) receptor antagonist may produce a faster antidepressant-like effect in animal models, than do antidepressant drugs, e.g., imipramine. The present work was aimed at examining the effect of single and repeated (14 days) administration of SB 269970 on the 5-HT(7) receptor in the hippocampus. METHODS The reactivity of 5-HT(7) receptors was determined using 5-carboxamidotryptamine (5-CT), which increased the bursting frequency of spontaneous epileptiform activity in hippocampal slices. Additionally, the effects of SB 269970 administration on the affinity and density of 5-HT(7) receptors were investigated using [(3)H]-SB 269970 and the influence of SB 269970 and imipramine on mRNA expression levels of Gα(s) and Gα(12) mRNA were studied using RT-qPCR. RESULTS Acute and repeated treatment with SB 269970 led to attenuation of the excitatory effects of activation of 5-HT(7) receptors. Neither single nor repeated administration of SB 269970 changed the mean affinity of 5-HT(7) receptors for [(3)H]-SB 269970. Repeated, but not single, administration of SB 269970 decreased the maximum density of [(3)H]-SB 269970 binding sites. While administration of imipramine did not change the expression of mRNAs for Gα(s) and Gα(12) proteins after both single and repeated administration of SB 269970, a reduction in Gα(s) and Gα(12) mRNA expression levels was evident. CONCLUSIONS These findings indicate that even single administration of SB269970 induces functional desensitization of the 5-HT(7) receptor system, which precedes changes in the receptor density. This mechanism may be responsible for the rapid antidepressant-like effect of the 5-HT(7) antagonist in animal models.
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Affiliation(s)
- Krzysztof Tokarski
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, PL 31-343 Kraków, Poland.
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Locatelli F, Bottà L, Prestori F, Masetto S, D'Angelo E. Late-onset bursts evoked by mossy fibre bundle stimulation in unipolar brush cells: evidence for the involvement of H- and TRP-currents. J Physiol 2012; 591:899-918. [PMID: 23129798 DOI: 10.1113/jphysiol.2012.242180] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Synaptic transmission at central synapses has usually short latency and graded amplitude, thereby regulating threshold crossing and the probability of action potential generation. In the granular layer of the vestibulo-cerebellum, unipolar brush cells (UBCs) receive a giant synapse generating a stereotyped excitatory postsynaptic potential (EPSP)-burst complex with early-onset (∼2 ms) and high reliability. By using patch-clamp recordings in cerebellar slices of the rat vestibulo-cerebellum, we found that mossy fibre bundle stimulation also evoked (in ∼80% of cases) a late-onset burst (after tens to hundreds of milliseconds) independent of EPSP generation. Different from the early-onset, the late-onset burst delay decreased and its duration increased by raising stimulation intensity or the number of impulses. Although depending on synaptic activity, the late-onset response was insensitive to perfusion of APV ((2R)-5-amino-phosphonopentanoate), NBQX (2,3-dioxo-6-nitro-tetrahydrobenzo(f)quinoxaline-7-sulfonamide) and MCPG ((RS)-α-methyl-4-carboxyphenylglycine) and did not therefore depend on conventional glutamatergic transmission mechanisms. The late-onset response was initiated by a slow depolarizing ramp driven by activation of an H-current (sensitive to ZD7288 and Cs(+)) and of a TRP- (transient receptor potential) current (sensitive to SKF96365), while the high voltage-activated and high voltage-activated Ca(2+) currents (sensitive to nimodipine and mibefradil, respectively) played a negligible role. The late-onset burst was occluded by intracellular cAMP. These results indicate that afferent activity can regulate H- and TRP-current gating in UBCs generating synaptically driven EPSP-independent responses, in which the delay rather than amplitude is graded with the intensity of the input pattern. This modality of synaptic transmission may play an important role in regulating UBC activation and granular layer functions in the vestibulo-cerebellum.
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Affiliation(s)
- F Locatelli
- Department of Neuroscience, Via Mondino 2, I-27100 Pavia, Italy
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43
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Eriksson TM, Holst S, Stan TL, Hager T, Sjögren B, Ögren SO, Svenningsson P, Stiedl O. 5-HT1A and 5-HT7 receptor crosstalk in the regulation of emotional memory: Implications for effects of selective serotonin reuptake inhibitors. Neuropharmacology 2012; 63:1150-60. [DOI: 10.1016/j.neuropharm.2012.06.061] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/07/2012] [Accepted: 06/27/2012] [Indexed: 12/31/2022]
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Involvement of 5-HT7 receptors in the pathogenesis of temporal lobe epilepsy. Eur J Pharmacol 2012; 685:52-8. [DOI: 10.1016/j.ejphar.2012.04.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 11/21/2022]
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Compan V, Laurent L, Jean A, Macary C, Bockaert J, Dumuis A. Serotonin signaling in eating disorders. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/wmts.45] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Berumen LC, Rodríguez A, Miledi R, García-Alcocer G. Serotonin receptors in hippocampus. ScientificWorldJournal 2012; 2012:823493. [PMID: 22629209 PMCID: PMC3353568 DOI: 10.1100/2012/823493] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 12/08/2011] [Indexed: 11/21/2022] Open
Abstract
Serotonin is an ancient molecular signal and a recognized neurotransmitter brainwide distributed with particular presence in hippocampus. Almost all serotonin receptor subtypes are expressed in hippocampus, which implicates an intricate modulating system, considering that they can be localized as autosynaptic, presynaptic, and postsynaptic receptors, even colocalized within the same cell and being target of homo- and heterodimerization. Neurons and glia, including immune cells, integrate a functional network that uses several serotonin receptors to regulate their roles in this particular part of the limbic system.
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Affiliation(s)
- Laura Cristina Berumen
- Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario S/N, Cerro de las Campanas, Querétaro 76010, Mexico
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Freret T, Bouet V, Quiedeville A, Nee G, Dallemagne P, Rochais C, Boulouard M. Synergistic effect of acetylcholinesterase inhibition (donepezil) and 5-HT(4) receptor activation (RS67333) on object recognition in mice. Behav Brain Res 2012; 230:304-8. [PMID: 22348892 DOI: 10.1016/j.bbr.2012.02.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 02/02/2012] [Accepted: 02/06/2012] [Indexed: 01/03/2023]
Abstract
Facing inefficiency of current treatments to cure Alzheimer disease (AD), a pharmacological approach is now emerging on the assumption that a single compound may be able to hit multiple targets, namely Multi-Target-Directed Ligands (MTDLs). Displaying numerous advantages, several MTDL for AD have been recently described but none associating an inhibition of AChE and an activation of 5-HT(4)R. The aim of this study was to validate the concept of a synergistic action of these two targets on episodic-like memory performances in mice. Among potent molecules, RS67333, a reference 5-HT(4)R agonist and donepezil (DNPZ), a reference acetylcholinesterase inhibitor, have been particularly chosen because of their close chemical structure. Administered separately, RS67333 (0.3 and 1mg/kg) and DNPZ (1mg/kg) improved recognition performances compared to saline treated animals but not with lower doses. Co-administration of subactive doses of RS67333 (0.1mg/kg) and DNPZ (0.3mg/kg) improved memory, moreover, this improvement is prevented if a 5-HT(4)R antagonist (GR125487, 10mg/kg) is also administered. Activation of 5-HT(4)R combined with inhibition of AChE with subactive doses of RS67333 and of DNPZ has synergistic effects on memory performances in mice. These molecules having close chemical structures, the synergistic effect of their combination affords new hope to chemist for the synthesis of MTDL.
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Affiliation(s)
- Thomas Freret
- Université de Caen Basse, Normandie, EA 4259 - Groupe Mémoire & Plasticité comportementale, F-14032 Caen, France
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Liu S, Aungst JL, Puche AC, Shipley MT. Serotonin modulates the population activity profile of olfactory bulb external tufted cells. J Neurophysiol 2011; 107:473-83. [PMID: 22013233 DOI: 10.1152/jn.00741.2011] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Serotonergic neurons in the raphe nuclei constitute one of the most prominent neuromodulatory systems in the brain. Projections from the dorsal and median raphe nuclei provide dense serotonergic innervation of the glomeruli of olfactory bulb. Odor information is initially processed by glomeruli, thus serotonergic modulation of glomerular circuits impacts all subsequent odor coding in the olfactory system. The present study discloses that serotonin (5-HT) produces excitatory modulation of external tufted (ET) cells, a pivotal neuron in the operation of glomerular circuits. The modulation is due to a transient receptor potential (TRP) channel-mediated inward current induced by activation of 5-HT(2A) receptors. This current produces membrane depolarization and increased bursting frequency in ET cells. Interestingly, the magnitude of the inward current and increased bursting inversely correlate with ET cell spontaneous (intrinsic) bursting frequency: slower bursting ET cells are more strongly modulated than faster bursting cells. Serotonin thus differentially impacts ET cells such that the mean bursting frequency of the population is increased. This centrifugal modulation could impact odor processing by: 1) increasing ET cell excitatory drive on inhibitory neurons to increase presynaptic inhibition of olfactory sensory inputs and postsynaptic inhibition of mitral/tufted cells; and/or 2) coordinating ET cell bursting with exploratory sniffing frequencies (5-8 Hz) to facilitate odor coding.
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Affiliation(s)
- Shaolin Liu
- Dept. of Anatomy and Neurobiology, Univ. of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA
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Fan LL, Zhang QJ, Liu J, Feng J, Gui ZH, Ali U, Zhang L, Hou C, Wang T, Hui YP, Sun YN, Wu ZH. In vivo effect of 5-HT₇ receptor agonist on pyramidal neurons in medial frontal cortex of normal and 6-hydroxydopamine-lesioned rats: an electrophysiological study. Neuroscience 2011; 190:328-38. [PMID: 21684321 DOI: 10.1016/j.neuroscience.2011.06.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 05/30/2011] [Accepted: 06/04/2011] [Indexed: 11/28/2022]
Abstract
The 5-hydroxytryptamine (5-HT)-7 receptor began to be cloned and pharmacologically characterized close to 20 years ago. It couples positively via G-proteins to adenylyl cyclase and activation of this receptor increases neuronal excitability, and several studies have shown that degeneration of the nigrostriatal pathway leads to an impairment of 5-HT system. Here we reported that systemic and local administration of 5-HT₇ receptor agonist AS 19 produced excitation, inhibition and no change in the firing rate of pyramidal neurons in medial prefrontal cortex (mPFC) of normal and 6-hydroxydopamine-lesioned rats. In normal rats, the mean response of the pyramidal neurons to AS 19 by systemic and local administration in mPFC was excitatory. The inhibitory effect by systemic administration of AS 19 was reversed by GABA(A) receptor antagonist picrotoxinin. Systemic administration of picrotoxinin excited all the neurons examined in normal rats, and after treatment with picrotoxinin, the local administration of AS 19 further increased the firing rate of the neurons. In the lesioned rats, systemic administration of AS 19, at the same doses, also increased the mean firing rate of the pyramidal neurons. However, cumulative dose producing excitation in the lesioned rats was higher than that of normal rats. Systemic administration of AS 19 produced inhibitory effect in the lesioned rats, which was partially reversed by picrotoxinin. The local administration of AS 19, at the same dose, did not change the firing rate of the neurons in the lesioned rats. Systemic administration of picrotoxinin and the local administration of AS 19 did not affect the firing rate of the neurons in the lesioned rats. These results indicate that activity of mPFC pyramidal neurons is regulated through activation of 5-HT₇ receptor by direct or indirect action, and degeneration of the nigrostriatal pathway leads to decreased response of these neurons to AS 19, suggesting dysfunction and/or down-regulation of 5-HT₇ receptor on the pyramidal neurons and GABA interneurons in the lesioned rats.
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Affiliation(s)
- L L Fan
- Department of Physiology and Pathophysiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, PR China
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Costa L, Trovato C, Musumeci S, Catania M, Ciranna L. 5-HT1A and 5-HT7 receptors differently modulate AMPA receptor-mediated hippocampal synaptic transmission. Hippocampus 2011; 22:790-801. [DOI: 10.1002/hipo.20940] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2011] [Indexed: 11/09/2022]
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