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Brunetti L, Francavilla F, Leopoldo M, Lacivita E. Allosteric Modulators of Serotonin Receptors: A Medicinal Chemistry Survey. Pharmaceuticals (Basel) 2024; 17:695. [PMID: 38931362 PMCID: PMC11206742 DOI: 10.3390/ph17060695] [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: 04/30/2024] [Revised: 05/15/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024] Open
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter regulating numerous physiological functions, and its dysregulation is a crucial component of the pathological processes of schizophrenia, depression, migraines, and obesity. 5-HT interacts with 14 different receptors, of which 5-HT1A-1FRs, 5-HT2A-CRs, and 5-HT4-7Rs are G protein-coupled receptors (GPCRs), while 5-HT3R is a ligand-gated ion channel. Over the years, selective orthosteric ligands have been identified for almost all serotonin receptors, yielding several clinically relevant drugs. However, the high degree of homology between 5-HTRs and other GPCRs means that orthosteric ligands can have severe side effects. Thus, there has recently been increased interest in developing safer ligands of GPCRs, which bind to less conserved, more specific sites, distinct from that of the receptor's natural ligand. The present review describes the identification of allosteric ligands of serotonin receptors, which are largely natural compounds (oleamide, cannabidiol, THC, and aporphine alkaloids), complemented by synthetic modulators developed in large part for the 5-HT2C receptor. The latter are positive allosteric modulators sought after for their potential as drugs preferable over the orthosteric agonists as antiobesity agents for their potentially safer profile. When available, details on the interactions between the ligand and allosteric binding site will be provided. An outlook on future research in the field will also be provided.
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Affiliation(s)
| | | | - Marcello Leopoldo
- Department of Pharmacy–Drug Sciences, University of Bari Aldo Moro, 70125 Bari, Italy; (L.B.); (F.F.); (E.L.)
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2
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Mallaroni P, Mason NL, Kloft L, Reckweg JT, van Oorsouw K, Ramaekers JG. Cortical structural differences following repeated ayahuasca use hold molecular signatures. Front Neurosci 2023; 17:1217079. [PMID: 37869513 PMCID: PMC10585114 DOI: 10.3389/fnins.2023.1217079] [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: 05/04/2023] [Accepted: 09/21/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction Serotonergic psychedelics such as ayahuasca are reported to promote both structural and functional neural plasticity via partial 5-HT2A agonism. However, little is known about how these molecular mechanisms may extend to repeated psychedelic administration in humans, let alone neuroanatomy. While early evidence suggests localised changes to cortical thickness in long-term ayahuasca users, it is unknown how such findings may be reflected by large-scale anatomical brain networks comprising cytoarchitecturally complex regions. Methods Here, we examined the relationship between cortical gene expression markers of psychedelic action and brain morphometric change following repeated ayahuasca usage, using high-field 7 Tesla neuroimaging data derived from 24 members of an ayahuasca-using church (Santo Daime) and case-matched controls. Results Using a morphometric similarity network (MSN) analysis, repeated ayahuasca use was associated with a spatially distributed cortical patterning of both structural differentiation in sensorimotor areas and de-differentiation in transmodal areas. Cortical MSN remodelling was found to be spatially correlated with dysregulation of 5-HT2A gene expression as well as a broader set of genes encoding target receptors pertinent to ayahuasca's effects. Furthermore, these associations were similarly interrelated with altered gene expression of specific transcriptional factors and immediate early genes previously identified in preclinical assays as relevant to psychedelic-induced neuroplasticity. Conclusion Taken together, these findings provide preliminary evidence that the molecular mechanisms of psychedelic action may scale up to a macroscale level of brain organisation in vivo. Closer attention to the role of cortical transcriptomics in structural-functional coupling may help account for the behavioural differences observed in experienced psychedelic users.
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Affiliation(s)
- Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Natasha L. Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Lilian Kloft
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Johannes T. Reckweg
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Kim van Oorsouw
- Department of Forensic Psychology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Johannes G. Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
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Jahanabadi S, Amiri S, Karkeh-Abadi M, Razmi A. Natural psychedelics in the treatment of depression; a review focusing on neurotransmitters. Fitoterapia 2023; 169:105620. [PMID: 37490982 DOI: 10.1016/j.fitote.2023.105620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/21/2023] [Accepted: 07/22/2023] [Indexed: 07/27/2023]
Abstract
Natural psychedelic compounds are emerging as potential novel therapeutics in psychiatry. This review will discuss how natural psychedelics exert their neurobiological therapeutic effects, and how different neurotransmission systems mediate the effects of these compounds. Further, current therapeutic strategies for depression, and novel mechanism of action of natural psychedelics in the treatment of depression will be discussed. In this review, our focus will be on N, N-dimethyltryptamine (DMT), reversible type A monoamine oxidase inhibitors, mescaline-containing cacti, psilocybin/psilocin-containing mushrooms, ibogaine, muscimol extracted from Amanita spp. mushrooms and ibotenic acid.
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Affiliation(s)
- Samane Jahanabadi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Shahid Sadoughi University of Medical Sciences, Yazd, Iran; Pharmaceutical Science Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Shayan Amiri
- Division of Neurodegenerative Disorders, St Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada; Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada.
| | - Mehdi Karkeh-Abadi
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran
| | - Ali Razmi
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran.
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4
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Tang ZH, Yu ZP, Li Q, Zhang XQ, Muhetaer K, Wang ZC, Xu P, Shen HW. The effects of serotonergic psychedelics in synaptic and intrinsic properties of neurons in layer II/III of the orbitofrontal cortex. Psychopharmacology (Berl) 2023; 240:1275-1285. [PMID: 37071130 DOI: 10.1007/s00213-023-06366-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/06/2023] [Indexed: 04/19/2023]
Abstract
RATIONALE Serotonergic psychedelics show promise in the treatment of psychiatric disorders, including obsessive-compulsive disorder. Dysfunction of the orbitofrontal cortex (OFc) has been implicated in the pathophysiology of compulsive behavior, which might be a key region for the efficacy of psychedelics. However, the effects of psychedelics on the neural activities and local excitation/inhibition (E/I) balance in the OFc are unclear. OBJECTIVES This study aimed to investigate how 25C-NBOMe, a substituted phenethylamine psychedelic, regulated the synaptic and intrinsic properties of neurons in layer II/III of the OFc. METHODS Acute brain slices containing the OFc of adult male Sprague Dawley rats were used for ex vivo whole-cell recording. The synaptic and intrinsic properties of neurons were monitored using voltage and current clamps, respectively. Electrically evoked action potential (eAP) was used to measure synaptic-driven pyramidal activity. RESULTS 25C-NBOMe enhanced spontaneous neurotransmission at glutamatergic synapses but diminished that in GABAergic synapses through the 5-HT2A receptor. 25C-NBOMe also increased both evoked excitatory currents and evoked action potentials. Moreover, 25C-NBOMe promoted the excitability of pyramidal neurons but not fast-spiking neurons. Either inhibiting G protein-gated inwardly rectifying potassium channels or activating protein kinase C significantly obstructed the facilitative effect of 25C-NBOMe on the intrinsic excitability of pyramidal neurons. CONCLUSIONS This work reveals the multiple roles of 25C-NBOMe in modulating synaptic and neuronal function in the OFc, which collectively promotes local E/I ratios.
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Affiliation(s)
- Zi-Hang Tang
- Department of Physiology and Pharmacology, School of Medicine, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China
| | - Zhi-Peng Yu
- Department of Physiology and Pharmacology, School of Medicine, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China
- Faculty of Electrical Engineering and Computer Science, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China
| | - Qiong Li
- Department of Physiology and Pharmacology, School of Medicine, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China
| | - Xiao-Qin Zhang
- Department of Physiology and Pharmacology, School of Medicine, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China
| | - Kadeliya Muhetaer
- Department of Physiology and Pharmacology, School of Medicine, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China
| | - Zheng-Chun Wang
- Department of Physiology and Pharmacology, School of Medicine, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China
| | - Peng Xu
- Key Laboratory of Drug Monitoring and Control, Drug Intelligence and Forensic Center, Ministry of Public Security, Beijing, 100093, People's Republic of China
| | - Hao-Wei Shen
- Department of Physiology and Pharmacology, School of Medicine, Ningbo University, 818 Fenghua Rd, Ningbo, Zhejiang, 315211, People's Republic of China.
- Key Laboratory of Addiction Research of Zhejiang Province, Ningbo Kangning Hospital, Ningbo, Zhejiang, 315010, People's Republic of China.
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5
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Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant. Biomolecules 2022; 12:biom12111618. [DOI: 10.3390/biom12111618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/27/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Ayahuasca is a psychoactive brew traditionally used in indigenous and religious rituals and ceremonies in South America for its therapeutic, psychedelic, and entheogenic effects. It is usually prepared by lengthy boiling of the leaves of the bush Psychotria viridis and the mashed stalks of the vine Banisteriopsis caapi in water. The former contains the classical psychedelic N,N-dimethyltryptamine (DMT), which is thought to be the main psychoactive alkaloid present in the brew. The latter serves as a source for β-carbolines, known for their monoamine oxidase-inhibiting (MAOI) properties. Recent preliminary research has provided encouraging results investigating ayahuasca’s therapeutic potential, especially regarding its antidepressant effects. On a molecular level, pre-clinical and clinical evidence points to a complex pharmacological profile conveyed by the brew, including modulation of serotoninergic, glutamatergic, dopaminergic, and endocannabinoid systems. Its substances also interact with the vesicular monoamine transporter (VMAT), trace amine-associated receptor 1 (TAAR1), and sigma-1 receptors. Furthermore, ayahuasca’s components also seem to modulate levels of inflammatory and neurotrophic factors beneficially. On a biological level, this translates into neuroprotective and neuroplastic effects. Here we review the current knowledge regarding these molecular interactions and how they relate to the possible antidepressant effects ayahuasca seems to produce.
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6
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Aoki J, Isokawa M, Toyoda M. Space and Time Coherent Mapping for Subcellular Resolution of Imaging Mass Spectrometry. Cells 2022; 11:cells11213382. [PMID: 36359779 PMCID: PMC9653616 DOI: 10.3390/cells11213382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/14/2022] [Accepted: 10/24/2022] [Indexed: 12/02/2022] Open
Abstract
Space and time coherent mapping (STCM) is a technology developed in our laboratory for improved matrix-assisted laser desorption ionization (MALDI) time of flight (TOF) imaging mass spectrometry (IMS). STCM excels in high spatial resolutions, which probe-based scanning methods cannot attain in conventional MALDI IMS. By replacing a scanning probe with a large field laser beam, focusing ion optics, and position-sensitive detectors, STCM tracks the entire flight trajectories of individual ions throughout the ionization process and visualizes the ionization site on the sample surface with a subcellular scale of precision and a substantially short acquisition time. Results obtained in thinly sectioned leech segmental ganglia and epididymis demonstrate that STCM IMS is highly suited for (1) imaging bioactive lipid messengers such as endocannabinoids and the mediators of neuronal activities in situ with spatial resolution sufficient to detail subcellular localization, (2) integrating resultant images in mass spectrometry to optically defined cell anatomy, and (3) assembling a stack of ion maps derived from mass spectra for cluster analysis. We propose that STCM IMS is the choice over a probe-based scanning mass spectrometer for high-resolution single-cell molecular imaging.
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Affiliation(s)
- Jun Aoki
- Center for Biosystems Dynamics Research, RIKEN, Saitama 351-0198, Japan
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
- Correspondence:
| | - Masako Isokawa
- Forefront Research Center, Graduate School of Science, Osaka University, Osaka 560-0043, Japan
| | - Michisato Toyoda
- Forefront Research Center, Graduate School of Science, Osaka University, Osaka 560-0043, Japan
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Dos Santos RG, Rocha JM, Rossi GN, Osório FL, Ona G, Bouso JC, Silveira GDO, Yonamine M, Marchioni C, Crevelin EJ, Queiroz ME, Crippa JA, Hallak JEC. Effects of ayahuasca on the endocannabinoid system of healthy volunteers and in volunteers with social anxiety disorder: Results from two pilot, proof-of-concept, randomized, placebo-controlled trials. Hum Psychopharmacol 2022; 37:e2834. [PMID: 35107855 DOI: 10.1002/hup.2834] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To assess endocannabinoid (anandamide, AEA; 2-arachidonoylglycerol, 2-AG) plasma levels in healthy volunteers and in volunteers with social anxiety disorder (SAD) after a single oral dose of ayahuasca or placebo. METHODS Post hoc analysis of endocannabinoid plasma levels (baseline, 90 and 240 min after drug intake) from two parallel-group, randomized, placebo-controlled trials. In Study 1, 20 healthy volunteers ingested ayahuasca (average 1.58 mg/ml dimethyltryptamine (DMT)) or placebo, and in Study 2, 17 volunteers with SAD received ayahuasca (average 0.680 mg/ml DMT) or placebo. RESULTS A significant difference was observed in AEA concentrations in Study 2 after ayahuasca intake (Χ2 (2) = 6.5, p = 0.03, Friedman test), and near significant differences (increases) were observed between baseline and 90 (Z = 0, p = 0.06, Wilcoxon test) and 240 (Z = 10, p = 0.06) minutes after ayahuasca intake. CONCLUSIONS Although our findings suggest that ayahuasca could modulate AEA levels in SAD patients, the high interindividual variability in both trials and the small samples preclude definitive conclusions. More research with larger samples is needed to better understand the effects of ayahuasca and other hallucinogens in the endocannabinoid system.
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Affiliation(s)
- Rafael G Dos Santos
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,National Institute of Science and Technology - Translational Medicine, Ribeirão Preto, Brazil.,ICEERS - International Center for Ethnobotanical Education, Research and Services, Barcelona, Spain
| | - Juliana Mendes Rocha
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Giordano Novak Rossi
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Flávia L Osório
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,National Institute of Science and Technology - Translational Medicine, Ribeirão Preto, Brazil
| | - Genís Ona
- ICEERS - International Center for Ethnobotanical Education, Research and Services, Barcelona, Spain.,Medical Anthropology Research Center (MARC), Universitat Rovira i Virgili, Tarragona, Spain
| | - José Carlos Bouso
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,ICEERS - International Center for Ethnobotanical Education, Research and Services, Barcelona, Spain.,Medical Anthropology Research Center (MARC), Universitat Rovira i Virgili, Tarragona, Spain
| | | | - Mauricio Yonamine
- School of Pharmaceutical Sciences, University of Sao Paulo, Ribeirão Preto, Brazil
| | - Camila Marchioni
- Department of Pathology, Federal University of Santa Catarina, Florianopolis, Brazil
| | | | - Maria Eugênia Queiroz
- National Institute of Science and Technology - Translational Medicine, Ribeirão Preto, Brazil.,Departament of Chemistry, University of São Paulo, Ribeirão Preto, Brazil.,School of Pharmaceutical Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - José Alexandre Crippa
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,National Institute of Science and Technology - Translational Medicine, Ribeirão Preto, Brazil
| | - Jaime E C Hallak
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,National Institute of Science and Technology - Translational Medicine, Ribeirão Preto, Brazil
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8
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Todorović M, Micov A, Nastić K, Tomić M, Pecikoza U, Vuković M, Stepanović-Petrović R. Vortioxetine as an analgesic in preclinical inflammatory pain models: Mechanism of action. Fundam Clin Pharmacol 2021; 36:237-249. [PMID: 34820899 DOI: 10.1111/fcp.12737] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/02/2021] [Accepted: 11/18/2021] [Indexed: 01/10/2023]
Abstract
Vortioxetine is a novel atypical antidepressant with multimodal activity that has recently demonstrated efficacy against neuropathic pain. There is no published data about its analgesic properties in models characterized by peripheral inflammation and consequent pain pathway sensitization, nor data on its mechanism of antinociceptive action. This study aimed to investigate vortioxetine's antinociceptive/antihyperalgesic effects in trigeminal, visceral, and somatic inflammatory pain models, and provide evidence on its mechanism of action in the modulation of trigeminal nociception. Vortioxetine's effects on the nociceptive behavior in orofacial formalin test (OFT) and acetic acid-writhing test in mice and on mechanical hyperalgesia in carrageenan-induced paw inflammation in rats were examined following peroral single administration. The involvement of serotonergic/adrenergic/cholinergic/cannabinoid/adenosine receptors was evaluated in OFT by intraperitoneally treating mice with an appropriate antagonist immediately after vortioxetine application. We used antagonists of 5-HT1B/1D serotonergic (GR 127935), α1 -adrenergic (prazosin), α2 -adrenergic (yohimbine), β1 -adrenergic (metoprolol), muscarinic (atropine), α7 nicotinic (methyllycaconitine), CB1 /CB2 cannabinoid (AM251 and AM630), and adenosine A1 (DPCPX) receptors. Vortioxetine dose-dependently reduced pain behavior in OFT and acetic acid writhing test, as well as inflammatory hyperalgesia in paw pressure test. All examined antagonists except prazosin dose-dependently inhibited vortioxetine's antinociceptive effects. In conclusion, vortioxetine exerted analgesic efficacy in trigeminal, visceral, and somatic inflammatory pain. The effect is at least in part mediated by 5-HT1B/1D serotonergic, α2 /β1 -adrenergic, muscarinic and nicotinic cholinergic, CB1 /CB2 cannabinoid, and adenosine A1 receptors. These findings contribute to better understanding of the analgesic effect of vortioxetine and suggest its potential usefulness for inflammatory pain treatment.
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Affiliation(s)
- Marija Todorović
- Department of Pharmacology, University of Belgrade - Faculty of Pharmacy, Belgrade, Serbia
| | - Ana Micov
- Department of Pharmacology, University of Belgrade - Faculty of Pharmacy, Belgrade, Serbia
| | - Katarina Nastić
- Department of Pharmacology, University of Belgrade - Faculty of Pharmacy, Belgrade, Serbia
| | - Maja Tomić
- Department of Pharmacology, University of Belgrade - Faculty of Pharmacy, Belgrade, Serbia
| | - Uroš Pecikoza
- Department of Pharmacology, University of Belgrade - Faculty of Pharmacy, Belgrade, Serbia
| | - Milja Vuković
- Department of Pharmacology, University of Belgrade - Faculty of Pharmacy, Belgrade, Serbia
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9
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Ahmadi-Mahmoodabadi N, Emamghoreishi M, Nasehi M, Zarrindast MR. The bidirectional effect of prelimbic 5-hydroxytryptamine type-4 (5-HT4) receptors on ACPA-mediated aversive memory impairment in adult male Sprague-Dawley rats. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2021; 24:726-733. [PMID: 34630949 PMCID: PMC8487599 DOI: 10.22038/ijbms.2021.49501.11317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 05/01/2021] [Indexed: 11/06/2022]
Abstract
Objectives This study aimed at investigating the effect of serotonergic 5-HT4 receptor agonist/antagonist on memory consolidation deficit induced by ACPA (a potent, selective CB1 cannabinoid receptor agonist) in the pre-limbic (PL) cortex. Materials and Methods We used the step-through passive avoidance test to evaluate memory consolidation of male Sprague-Dawley (SD) rats. Bilateral post-training microinjections of the drugs were done in a volume of 0.6 μl/rat into the PL area (0.3 μl per side). Results The results showed a significant interaction between RS67333 hydrochloride (5-HT4 receptor agonist) or RS23597-190 hydrochloride (5-HT4 receptor antagonist) and ACPA on consolidation of aversive memory. RS67333 hydrochloride (0.5 μg/rat) enhanced consolidation of memory and its co-administration at the ineffective dose of 0.005 μg/rat with ineffective (0.001 μg/rat) or effective (0.1 μg/rat) doses of ACPA improved and prevented impairment of memory caused by ACPA, respectively. In other words, RS67333 had a bidirectional effect on ACPA-caused amnesia. While RS23597-190 hydrochloride had no effect on memory at the doses used (0.005, 0.01, 0.1, or 0.5 μg/rat); but its concomitant use with an effective dose of ACPA (0.1 μg/rat) potentiated amnesia. None of the drugs had an effect on locomotor activity. Conclusion This study revealed that activation or deactivation of the 5-HT4 receptors in the PL may mediate the IA memory impairment induced by ACPA indicating a modulatory role for the 5-HT4 serotonergic receptors.
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Affiliation(s)
- Nargol Ahmadi-Mahmoodabadi
- Institute for Cognitive Science Studies, Tehran, Iran.,Department of Basic Sciences, Campus of Shahid Bahonar, Farhangian University of Shiraz, Shiraz, Iran
| | - Masoumeh Emamghoreishi
- Department of Pharmacology, School of Medicine and Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Nasehi
- Cognitive and Neuroscience Research Center, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Mohammad-Reza Zarrindast
- Institute for Cognitive Science Studies, Tehran, Iran.,Cognitive and Neuroscience Research Center, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.,Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran, Iran
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10
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Winters BL, Vaughan CW. Mechanisms of endocannabinoid control of synaptic plasticity. Neuropharmacology 2021; 197:108736. [PMID: 34343612 DOI: 10.1016/j.neuropharm.2021.108736] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/13/2023]
Abstract
The endogenous cannabinoid transmitter system regulates synaptic transmission throughout the nervous system. Unlike conventional transmitters, specific stimuli induce synthesis of endocannabinoids (eCBs) in the postsynaptic neuron, and these travel backwards to modulate presynaptic inputs. In doing so, eCBs can induce short-term changes in synaptic strength and longer-term plasticity. While this eCB regulation is near ubiquitous, it displays major regional and synapse specific variations with different synapse specific forms of short-versus long-term plasticity throughout the brain. These differences are due to the plethora of pre- and postsynaptic mechanisms which have been implicated in eCB signalling, the intricacies of which are only just being realised. In this review, we shall describe the current understanding and highlight new advances in this area, with a focus on the retrograde action of eCBs at CB1 receptors (CB1Rs).
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Affiliation(s)
- Bryony Laura Winters
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia.
| | - Christopher Walter Vaughan
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia
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11
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Vaughn SE, Strawn JR, Poweleit EA, Sarangdhar M, Ramsey LB. The Impact of Marijuana on Antidepressant Treatment in Adolescents: Clinical and Pharmacologic Considerations. J Pers Med 2021; 11:jpm11070615. [PMID: 34209709 PMCID: PMC8307883 DOI: 10.3390/jpm11070615] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/12/2022] Open
Abstract
The neuropharmacology of marijuana, including its effects on selective serotonin reuptake inhibitor (SSRI)/antidepressant metabolism and the subsequent response and tolerability in youth, has received limited attention. We sought to (1) review clinically relevant pharmacokinetic (PK) and pharmacodynamic (PD) interactions between cannabinoids and selected SSRIs, (2) use PK models to examine the impact of cannabinoids on SSRI exposure (area under curve (AUC)) and maximum concentration (CMAX) in adolescents, and (3) examine the frequency of adverse events reported when SSRIs and cannabinoids are used concomitantly. Cannabinoid metabolism, interactions with SSRIs, impact on relevant PK/PD pathways and known drug–drug interactions were reviewed. Then, the impact of tetrahydrocannabinol (THC) and cannabidiol (CBD) on exposure (AUC24) and CMAX for escitalopram and sertraline was modeled using pediatric PK data. Using data from the Food and Drug Administration Adverse Events Reporting System (FAERS), the relationship between CBD and CYP2C19-metabolized SSRIs and side effects was examined. Cannabis and CBD inhibit cytochrome activity, alter serotonergic transmission, and modulate SSRI response. In PK models, CBD and/or THC increases sertraline and es/citalopram concentrations in adolescents, and coadministration of CBD and CYP2C19-metabolized SSRIs increases the risk of cough, diarrhea, dizziness, and fatigue. Given the significant SSRI–cannabinoid interactions, clinicians should discuss THC and CBD use in youth prescribed SSRIs and be aware of the impact of initiating, stopping, or decreasing cannabinoid use as this may significantly affect es/citalopram and sertraline exposure.
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Affiliation(s)
- Samuel E. Vaughn
- Division of Child and Adolescent Psychiatry, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA;
- Correspondence: ; Tel.: +1-513-636-4788
| | - Jeffrey R. Strawn
- Division of Child and Adolescent Psychiatry, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA;
- Department of Psychiatry and Behavioral Neuroscience, College of Medicine, University of Cincinnati, Cincinnati, OH 45219, USA
- Division of Clinical Pharmacology, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA;
| | - Ethan A. Poweleit
- Division of Biomedical Informatics, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA; (E.A.P.); (M.S.)
- Division of Research in Patient Services, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Mayur Sarangdhar
- Division of Biomedical Informatics, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA; (E.A.P.); (M.S.)
- Department of Biomedical Informatics, College of Medicine, University of Cincinnati, Cincinnati, OH 45219, USA
- Cancer and Blood Diseases Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Laura B. Ramsey
- Division of Clinical Pharmacology, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA;
- Division of Research in Patient Services, Cincinnati Children’s Hospital Medical Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
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12
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Kesner AJ, Lovinger DM. Cannabis use, abuse, and withdrawal: Cannabinergic mechanisms, clinical, and preclinical findings. J Neurochem 2021; 157:1674-1696. [PMID: 33891706 PMCID: PMC9291571 DOI: 10.1111/jnc.15369] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 12/14/2022]
Abstract
Cannabis sativa is the most widely used illicit drug in the world. Its main psychoactive component is delta‐9‐tetrahydrocannabinol (THC), one of over 100 phytocannabinoid compounds produced by the cannabis plant. THC is the primary compound that drives cannabis abuse potential and is also used and prescribed medically for therapeutic qualities. Despite its therapeutic potential, a significant subpopulation of frequent cannabis or THC users will develop a drug use syndrome termed cannabis use disorder. Individuals suffering from cannabis use disorder exhibit many of the hallmarks of classical addictions including cravings, tolerance, and withdrawal symptoms. Currently, there are no efficacious treatments for cannabis use disorder or withdrawal symptoms. This makes both clinical and preclinical research on the neurobiological mechanisms of these syndromes ever more pertinent. Indeed, basic research using animal models has provided valuable evidence of the neural molecular and cellular actions of cannabis that mediate its behavioral effects. One of the main components being central action on the cannabinoid type‐one receptor and downstream intracellular signaling related to the endogenous cannabinoid system. Back‐translational studies have provided insight linking preclinical basic and behavioral biology research to better understand symptoms observed at the clinical level. This narrative review aims to summarize major research elucidating the molecular, cellular, and behavioral manifestations of cannabis/THC use that play a role in cannabis use disorder and withdrawal.
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Affiliation(s)
- Andrew J Kesner
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Center on Compulsive Behaviors, National Institutes of Health, Bethesda, MD, USA
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Center on Compulsive Behaviors, National Institutes of Health, Bethesda, MD, USA
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13
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Colangeli R, Teskey GC, Di Giovanni G. Endocannabinoid-serotonin systems interaction in health and disease. PROGRESS IN BRAIN RESEARCH 2021; 259:83-134. [PMID: 33541682 DOI: 10.1016/bs.pbr.2021.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endocannabinoid (eCB) and serotonin (5-HT) neuromodulatory systems work both independently and together to finely orchestrate neuronal activity throughout the brain to strongly sculpt behavioral functions. Surprising parallelism between the behavioral effects of 5-HT and eCB activity has been widely reported, including the regulation of emotional states, stress homeostasis, cognitive functions, food intake and sleep. The distribution pattern of the 5-HT system and the eCB molecular elements in the brain display a strong overlap and several studies report a functional interplay and even a tight interdependence between eCB/5-HT signaling. In this review, we examine the available evidence of the interaction between the eCB and 5-HT systems. We first introduce the eCB system, then we describe the eCB/5-HT crosstalk at the neuronal and synaptic levels. Finally, we explore the potential eCB/5-HT interaction at the behavioral level with the implication for psychiatric and neurological disorders. The precise elucidation of how this neuromodulatory interaction dynamically regulates biological functions may lead to the development of more targeted therapeutic strategies for the treatment of depressive and anxiety disorders, psychosis and epilepsy.
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Affiliation(s)
- Roberto Colangeli
- Section of Neuroscience and Cell Biology, Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
| | - G Campbell Teskey
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - 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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Ibarra-Lecue I, Diez-Alarcia R, Urigüen L. Serotonin 2A receptors and cannabinoids. PROGRESS IN BRAIN RESEARCH 2021; 259:135-175. [PMID: 33541675 DOI: 10.1016/bs.pbr.2021.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Accumulating evidence has proven that both exogenous cannabinoids as well as imbalances in the endocannabinoid system are involved in the onset and development of mental disorders such as anxiety, depression, or schizophrenia. Extensive recent research in this topic has mainly focused on the molecular mechanisms by which cannabinoid agonists may contribute to the pathophysiology of these disorders. Initially, serotonin neurotransmitter garnered most attention due to its relationship to mood disorders and mental diseases, with little attention to specific receptors. To date, the focus has redirected toward the understanding of different serotonin receptors, through a demonstration of its versatile pharmacology and synergy with different modulators. Serotonin 2A receptors are a good example of this phenomenon, and the complex signaling that they trigger appears of high relevance in the context of mental disorders, especially in schizophrenia. This chapter will analyze most relevant attributes of serotonin 2A receptors and the endocannabinoid system, and will highlight the evidence toward the functional bidirectional interaction between these elements in the brain as well as the impact of the endocannabinoid system dysregulation on serotonin 2A receptors functionality.
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Affiliation(s)
- Inés Ibarra-Lecue
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain; Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Madrid, Spain
| | - Rebeca Diez-Alarcia
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain; Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Madrid, Spain; Biocruces Bizkaia Health Research Institute, Bizkaia, Spain
| | - Leyre Urigüen
- Department of Pharmacology, University of the Basque Country, UPV/EHU, Leioa, Spain; Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Madrid, Spain; Biocruces Bizkaia Health Research Institute, Bizkaia, Spain.
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15
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Elevated Brain Fatty Acid Amide Hydrolase Induces Depressive-Like Phenotypes in Rodent Models: A Review. Int J Mol Sci 2021; 22:ijms22031047. [PMID: 33494322 PMCID: PMC7864498 DOI: 10.3390/ijms22031047] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 12/17/2022] Open
Abstract
Altered activity of fatty acid amide hydrolase (FAAH), an enzyme of the endocannabinoid system, has been implicated in several neuropsychiatric disorders, including major depressive disorder (MDD). It is speculated that increased brain FAAH expression is correlated with increased depressive symptoms. The aim of this scoping review was to establish the role of FAAH expression in animal models of depression to determine the translational potential of targeting FAAH in clinical studies. A literature search employing multiple databases was performed; all original articles that assessed FAAH expression in animal models of depression were considered. Of the 216 articles that were screened for eligibility, 24 articles met inclusion criteria and were included in this review. Three key findings emerged: (1) FAAH expression is significantly increased in depressive-like phenotypes; (2) genetic knockout or pharmacological inhibition of FAAH effectively reduces depressive-like behavior, with a dose-dependent effect; and (3) differences in FAAH expression in depressive-like phenotypes were largely localized to animal prefrontal cortex, hippocampus and striatum. We conclude, based on the animal literature, that a positive relationship can be established between brain FAAH level and expression of depressive symptoms. In summary, we suggest that FAAH is a tractable target for developing novel pharmacotherapies for MDD.
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16
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Fonseca R, Madeira N, Simoes C. Resilience to fear: The role of individual factors in amygdala response to stressors. Mol Cell Neurosci 2020; 110:103582. [PMID: 33346000 DOI: 10.1016/j.mcn.2020.103582] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 11/13/2020] [Accepted: 12/02/2020] [Indexed: 10/22/2022] Open
Abstract
Resilience to stress is an adaptive process that varies individually. Resilience refers to the adaptation, or the ability to maintain or regain mental health, despite being subject to adverse situation. Resilience is a dynamic concept that reflects a combination of internal individual factors, including age and gender interacting with external factors such as social, cultural and environmental factors. In the last decade, we have witnessed an increase in the prevalence of anxiety disorders, including post-traumatic stress disorder. Given that stress in unavoidable, it is of great interest to understand the neurophysiological mechanisms of resilience, the individual factors that may contribute to susceptibility and promote efficacious approaches to improve resilience. Here, we address this complex question, attempting at defining clear and operational definitions that may allow us to improve our analysis of behavior incorporating individuality. We examine how individual perception of the stressor can alter the outcome of an adverse situation using as an example, the fear-conditioning paradigm and discuss how individual differences in the reward system can contribute to resilience. Given the central role of the endocannabinoid system in regulating fear responses and anxiety, we discuss the evidence that polymorphisms in several molecules of this signaling system contribute to different anxiety phenotypes. The endocannabinoid system is highly interconnected with the serotoninergic and dopaminergic modulatory systems, contributing to individual differences in stress perception and coping mechanisms. We review how the individual variability in these modulatory systems can be used towards a multivariable assessment of stress risk. Incorporating individuality in our research will allow us to define biomarkers of anxiety disorders as well as assess prognosis, towards a personalized clinical approach to mental health.
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Affiliation(s)
- Rosalina Fonseca
- Cellular and Systems Neurobiology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130 1169-056 Lisboa, Portugal.
| | - Natália Madeira
- Cellular and Systems Neurobiology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130 1169-056 Lisboa, Portugal
| | - Carla Simoes
- Cellular and Systems Neurobiology, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130 1169-056 Lisboa, Portugal
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17
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Ruthirakuhan M, Herrmann N, Andreazza AC, Verhoeff NPLG, Gallagher D, Black SE, Kiss A, Lanctôt KL. 24S-Hydroxycholesterol Is Associated with Agitation Severity in Patients with Moderate-to-Severe Alzheimer's Disease: Analyses from a Clinical Trial with Nabilone. J Alzheimers Dis 2020; 71:21-31. [PMID: 31322567 PMCID: PMC6839471 DOI: 10.3233/jad-190202] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background: Agitation is a prevalent and difficult-to-treat symptom of Alzheimer’s disease (AD). The endocannabinoid system (ECS) has been a target of interest for the treatment of agitation. However, ECS signaling may interact with AD-related changes in brain cholesterol metabolism. Elevated brain cholesterol, reflected by reduced serum 24-S-hydroxycholesterol (24S-OHC), is associated with reduced membrane fluidity, preventing ligand binding to cannabinoid receptor 1. Objective: To assess whether 24S-OHC was associated with agitation severity and response to nabilone. Methods: 24S-OHC was collected from AD patients enrolled in a clinical trial on nabilone at the start and end of each phase. This allowed for the cross-sectional and longitudinal investigation between 24S-OHC and agitation (Cohen Mansfield Agitation Inventory, CMAI). Post-hoc analyses included adjustments for baseline standardized Mini-Mental Status Exam (sMMSE), and analyses with CMAI subtotals consistent with the International Psychogeriatric Association (IPA) definition for agitation (physical aggression and nonaggression, and verbal aggression). Results: 24S-OHC was not associated with CMAI scores cross-sectionally or longitudinally, before and after adjusting for baseline sMMSE. However, 24S-OHC was associated with greater CMAI IPA scores at baseline (F(1,36) = 4.95, p = 0.03). In the placebo phase only, lower 24S-OHC at baseline was associated with increases in CMAI IPA scores (b = –35.2, 95% CI –65.6 to –5.0, p = 0.02), and decreases in 24S-OHC were associated with increases in CMAI IPA scores (b = –20.94, 95% CI –57.9 to –4.01, p = 0.03). Conclusion: 24S-OHC was associated with agitation severity cross-sectionally, and longitudinally in patients with AD. However, 24S-OHC did not predict treatment response, and does not change over time with nabilone.
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Affiliation(s)
- Myuri Ruthirakuhan
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Nathan Herrmann
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Ana C Andreazza
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | | | - Damien Gallagher
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Sandra E Black
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Medicine (Neurology), University of Toronto and Sunnybrook HSC, Toronto, ON, Canada
| | - Alex Kiss
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Research Design and Biostatistics, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Krista L Lanctôt
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
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18
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Effects of combined 5-HT 2A and cannabinoid receptor modulation on a schizophrenia-related prepulse inhibition deficit in mice. Psychopharmacology (Berl) 2020; 237:1643-1655. [PMID: 32095916 DOI: 10.1007/s00213-020-05485-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 02/14/2020] [Indexed: 10/24/2022]
Abstract
RATIONALE Prepulse inhibition of the startle reflex (PPI) is disrupted in several psychiatric disorders including schizophrenia. Understanding PPI pharmacology may help elucidate the pathophysiology of these disorders and lead to better treatments. Given the advantages of multi-target approaches for complex mental illnesses treatment, we have investigated the interaction between receptors known to modulate PPI (5-HT1A and 5-HT2A) and the neuromodulatory endocannabinoid system. OBJECTIVES To investigate serotonin and cannabinoid receptor (CBR) co-modulation in a model of PPI disruption relevant to schizophrenia METHODS: Male Swiss mice were pretreated with WIN 55,212-2 (CBR agonist), rimonabant (CB1R inverse agonist), 8-OH-DPAT (5-HT1A/7 agonist), and volinanserin (5-HT2A antagonist) or with a combination of a cannabinoid and a serotonergic drug. PPI disruption was induced by acute administration of MK-801. RESULTS WIN 55,212-2 and rimonabant did not change PPI nor block MK-801-induced deficits. 8-OH-DPAT increased PPI in control mice and, in a higher dose, inhibited MK-801-induced impairments. Volinanserin also increased PPI in control and MK-801-treated mice, presenting an inverted U-shaped dose-response curve. Co-administration of either cannabinoid ligand with 8-OH-DPAT did not change PPI; however, the combination of volinanserin with rimonabant increased PPI in both control and MK-801-exposed mice. CONCLUSIONS WIN 55,212-2 and rimonabant had similar effects in PPI. Moreover, serotonin and cannabinoid receptors interact to modulate PPI. While co-modulation of CBR and 5-HT1A receptors did not change PPI, a beneficial effect of 5-HT2A and CB1R antagonist combination was detected, possibly mediated through potentiation of 5-HT2A blockade effects by concomitant CB1R blockade.
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19
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Winters BL, Jeong HJ, Vaughan CW. Inflammation induces developmentally regulated sumatriptan inhibition of spinal synaptic transmission. Br J Pharmacol 2020; 177:3730-3743. [PMID: 32352556 DOI: 10.1111/bph.15089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE While triptans are used to treat migraine, there is evidence that they also reduce inflammation-induced pain at the spinal level. The cellular mechanisms underlying this spinal enhancement are unknown. We examined whether inflammation alters sumatriptan modulation of synaptic transmission in the rat spinal dorsal horn. EXPERIMENTAL APPROACH Three to four days following intraplantar injection of complete Freund's adjuvant (CFA) or saline, whole cell recordings of evoked glutamatergic EPSCs were made from lumbar lamina I-II dorsal horn neurons in rat spinal slices KEY RESULTS: In 2- to 3-week-old animals, sumatriptan reduced the amplitude of evoked EPSCs and this was greater in slices from CFA, compared to saline-injected rats. In CFA-injected animals, sumatriptan increased the paired pulse ratio of evoked EPSCs and reduced the rate of spontaneous miniature EPSCs. The 5-HT1B and 5-HT1D agonists CP9 3129 and PNU109291 both inhibited evoked EPSCs in CFA but not saline-injected rats. By contrast, the 5-HT1A agonist R(+)-8-OH-DPAT inhibited evoked EPSCs in saline but not CFA-injected rats. In CFA-injected rats, the sumatriptan-induced inhibition of evoked EPSCs was reduced by the 5-HT1B and 5-HT1D antagonists NAS181 and BRL-15572. Intriguingly, the difference in sumatriptan inhibition between CFA and saline-injected animals was only observed in animals less than 4 weeks old. CONCLUSION AND IMPLICATIONS These findings indicate that inflammation induces a developmentally regulated 5-HT1B/1D presynaptic inhibition of excitatory transmission into the rat superficial dorsal horn. Thus, triptans could potentially act as spinal analgesic agents for inflammatory pain in the juvenile setting.
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Affiliation(s)
- Bryony L Winters
- Pain Management Research Institute and Kolling Institute of Medical Research, The University of Sydney at Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | - Hyo-Jin Jeong
- Pain Management Research Institute and Kolling Institute of Medical Research, The University of Sydney at Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | - Christopher W Vaughan
- Pain Management Research Institute and Kolling Institute of Medical Research, The University of Sydney at Royal North Shore Hospital, St. Leonards, New South Wales, Australia
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20
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Wanner NM, Colwell ML, Faulk C. The epigenetic legacy of illicit drugs: developmental exposures and late-life phenotypes. ENVIRONMENTAL EPIGENETICS 2019; 5:dvz022. [PMID: 31777665 PMCID: PMC6875650 DOI: 10.1093/eep/dvz022] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 10/11/2019] [Accepted: 10/14/2019] [Indexed: 05/24/2023]
Abstract
The effects of in utero exposure to illicit drugs on adult offspring are a significant and widespread but understudied global health concern, particularly in light of the growing opioid epidemic and emerging therapeutic uses for cannabis, ketamine, and MDMA. Epigenetic mechanisms including DNA methylation, histone modifications, and expression of non-coding RNAs provide a mechanistic link between the prenatal environment and health consequences years beyond the original exposure, and shifts in the epigenome present in early life or adolescence can lead to disease states only appearing during adulthood. The current review summarizes the literature assessing effects of perinatal illicit drug exposure on adult disease phenotypes as mediated by perturbations of the epigenome. Both behavioral and somatic phenotypes are included and studies reporting clinical data in adult offspring, epigenetic readouts in offspring of any age, or both phenotypic and epigenetic measures are prioritized. Studies of licit substances of abuse (i.e. alcohol, nicotine) are excluded with a focus on cannabis, psychostimulants, opioids, and psychedelics; current issues in the field and areas of interest for further investigation are also discussed.
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Affiliation(s)
- Nicole M Wanner
- Department of Veterinary and Biomedical Sciences, University of Minnesota College of Veterinary Medicine, 1988 Fitch Ave, 495B AnSc/VetMed, St. Paul, MN 55108, USA
| | - Mathia L Colwell
- Department of Animal Science, University of Minnesota College of Food, Agricultural and Natural Resource Natural Resource Sciences, 1988 Fitch Ave, 495B AnSc/VetMed, St. Paul, MN 55108, USA
| | - Christopher Faulk
- Department of Veterinary and Biomedical Sciences, University of Minnesota College of Veterinary Medicine, 1988 Fitch Ave, 495B AnSc/VetMed, St. Paul, MN 55108, USA
- Department of Animal Science, University of Minnesota College of Food, Agricultural and Natural Resource Natural Resource Sciences, 1988 Fitch Ave, 495B AnSc/VetMed, St. Paul, MN 55108, USA
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21
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Canal CE. Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action. Handb Exp Pharmacol 2019; 252:227-260. [PMID: 29532180 PMCID: PMC6136989 DOI: 10.1007/164_2018_107] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent, well-controlled - albeit small-scale - clinical trials show that serotonergic psychedelics, including psilocybin and lysergic acid diethylamide, possess great promise for treating psychiatric disorders, including treatment-resistant depression. Additionally, fresh results from a deluge of clinical neuroimaging studies are unveiling the dynamic effects of serotonergic psychedelics on functional activity within, and connectivity across, discrete neural systems. These observations have led to testable hypotheses regarding neural processing mechanisms that contribute to psychedelic effects and therapeutic benefits. Despite these advances and a plethora of preclinical and clinical observations supporting a central role for brain serotonin 5-HT2A receptors in producing serotonergic psychedelic effects, lingering and new questions about mechanisms abound. These chiefly pertain to molecular neuropharmacology. This chapter is devoted to illuminating and discussing such questions in the context of preclinical experimental approaches for studying mechanisms of action of serotonergic psychedelics, classic and new.
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Affiliation(s)
- Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA, USA.
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22
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Turecek J, Regehr WG. Neuronal Regulation of Fast Synaptotagmin Isoforms Controls the Relative Contributions of Synchronous and Asynchronous Release. Neuron 2019; 101:938-949.e4. [PMID: 30733150 DOI: 10.1016/j.neuron.2019.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 10/30/2018] [Accepted: 01/03/2019] [Indexed: 10/27/2022]
Abstract
Neurotransmitter release can be synchronous and occur within milliseconds of action potential invasion, or asynchronous and persist for tens of milliseconds. The molecular determinants of release kinetics remain poorly understood. It has been hypothesized that asynchronous release dominates when fast Synaptotagmin isoforms are far from calcium channels or when specialized sensors, such as Synaptotagmin 7, are abundant. Here we test these hypotheses for GABAergic projections onto neurons of the inferior olive, where release in different subnuclei ranges from synchronous to asynchronous. Surprisingly, neither of the leading hypotheses accounts for release kinetics. Instead, we find that rapid Synaptotagmin isoforms are abundant in subnuclei with synchronous release but absent where release is asynchronous. Viral expression of Synaptotagmin 1 transforms asynchronous synapses into synchronous ones. Thus, the nervous system controls levels of fast Synaptotagmin isoforms to regulate release kinetics and thereby controls the ability of synapses to encode spike rates or precise timing.
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Affiliation(s)
- Josef Turecek
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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23
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Colangeli R, Di Maio R, Pierucci M, Deidda G, Casarrubea M, Di Giovanni G. Synergistic action of CB 1 and 5-HT 2B receptors in preventing pilocarpine-induced status epilepticus in rats. Neurobiol Dis 2019; 125:135-145. [PMID: 30716469 DOI: 10.1016/j.nbd.2019.01.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/24/2019] [Accepted: 01/31/2019] [Indexed: 11/30/2022] Open
Abstract
Endocannabinoids (eCBs) and serotonin (5-HT) play a neuromodulatory role in the central nervous system. Both eCBs and 5-HT regulate neuronal excitability and their pharmacological potentiation has been shown to control seizures in pre-clinical and human studies. Compelling evidence indicates that eCB and 5-HT systems interact to modulate several physiological and pathological brain functions, such as food intake, pain, drug addiction, depression, and anxiety. Nevertheless, there is no evidence of an eCB/5-HT interaction in experimental and human epilepsies, including status epilepticus (SE). Here, we performed video-EEG recording in behaving rats treated with the pro-convulsant agent pilocarpine (PILO), in order to study the effect of the activation of CB1/5-HT2 receptors and their interaction on SE. Synthetic cannabinoid agonist WIN55,212-2 (WIN) decreased behavioral seizure severity of PILO-induced SE at 2 mg/kg (but not at 1 and 5 mg/kg, i.p.), while 5-HT2B/2C receptor agonist RO60-0175 (RO; 1, 3, 10 mg/kg, i.p.) was devoid of any effect. RO 3 mg/kg was instead capable of potentiating the effect of WIN 2 mg/kg on the Racine scale score. Surprisingly, neither WIN 2 mg/kg nor RO 3 mg/kg had any effect on the incidence and the intensity of EEG seizures when administered alone. However, WIN+RO co-administration reduced the incidence and the severity of EEG SE and increased the latency to SE onset after PILO injection. WIN+RO effects were blocked by the selective CB1R antagonist AM251 and the 5-HT2BR antagonist RS127445, but not by the 5-HT2CR antagonist SB242084 or the 5-HT2AR antagonist MDL11,939. These data revealed a synergistic interaction between CB1R/5-HT2BR in the expression of PILO-induced SE.
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Affiliation(s)
- Roberto Colangeli
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta.
| | - Roberto Di Maio
- Pittsburgh Inst. for Neurodegenerative Dis., Dept. of Neurology, Univ. of Pittsburgh, PA, USA
| | - Massimo Pierucci
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Gabriele Deidda
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Maurizio Casarrubea
- Department of Experimental Biomedicine and Clinical Neurosciences, Human Physiology Section "Giuseppe Pagano", University of Palermo, Palermo, Italy
| | - Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; School of Biosciences, Cardiff University, Cardiff, UK.
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Possible Interactions Between 5-HT2A Receptors and the Endocannabinoid System in Humans: Preliminary Evidence of Interactive Effects of Ayahuasca and Endocannabinoids in a Healthy Human Subject. J Clin Psychopharmacol 2018; 38:644-646. [PMID: 30339603 DOI: 10.1097/jcp.0000000000000973] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Turner BD, Kashima DT, Manz KM, Grueter CA, Grueter BA. Synaptic Plasticity in the Nucleus Accumbens: Lessons Learned from Experience. ACS Chem Neurosci 2018; 9:2114-2126. [PMID: 29280617 DOI: 10.1021/acschemneuro.7b00420] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Synaptic plasticity contributes to behavioral adaptations. As a key node in the reward pathway, the nucleus accumbens (NAc) is important for determining motivation-to-action outcomes. Across animal models of motivation including addiction, depression, anxiety, and hedonic feeding, selective recruitment of neuromodulatory signals and plasticity mechanisms have been a focus of physiologists and behaviorists alike. Experience-dependent plasticity mechanisms within the NAc vary depending on the distinct afferents and cell-types over time. A greater understanding of molecular mechanisms determining how these changes in synaptic strength track with behavioral adaptations will provide insight into the process of learning and memory along with identifying maladaptations underlying pathological behavior. Here, we summarize recent findings detailing how changes in NAc synaptic strength and mechanisms of plasticity manifest in various models of motivational disorders.
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Affiliation(s)
- Brandon D. Turner
- Vanderbilt Brain Institute, Nashville, Tennessee 37232, United States
| | - Daniel T. Kashima
- Vanderbilt Brain Institute, Nashville, Tennessee 37232, United States
- Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Kevin M. Manz
- Vanderbilt Brain Institute, Nashville, Tennessee 37232, United States
- Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Carrie A. Grueter
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Brad A. Grueter
- Vanderbilt Brain Institute, Nashville, Tennessee 37232, United States
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
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Augustin SM, Lovinger DM. Functional Relevance of Endocannabinoid-Dependent Synaptic Plasticity in the Central Nervous System. ACS Chem Neurosci 2018; 9:2146-2161. [PMID: 29400439 DOI: 10.1021/acschemneuro.7b00508] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The endocannabinoid (eCB) signaling system plays a key role in short-term and long-term synaptic plasticity in brain regions involved in various neural functions ranging from action selection to appetite control. This review will explore the role of eCBs in shaping neural circuit function to regulate behaviors. In particular, we will discuss the behavioral consequences of eCB mediated long-term synaptic plasticity in different brain regions. This review brings together evidence from in vitro and ex vivo studies and points out the need for more in vivo studies.
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Affiliation(s)
- Shana M. Augustin
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland 20852, United States
| | - David M. Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland 20852, United States
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Sánchez-Brualla I, Boulenguez P, Brocard C, Liabeuf S, Viallat-Lieutaud A, Navarro X, Udina E, Brocard F. Activation of 5-HT 2A Receptors Restores KCC2 Function and Reduces Neuropathic Pain after Spinal Cord Injury. Neuroscience 2018; 387:48-57. [PMID: 28844001 DOI: 10.1016/j.neuroscience.2017.08.033] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/26/2017] [Accepted: 08/14/2017] [Indexed: 11/30/2022]
Abstract
Downregulation of the potassium chloride cotransporter type 2 (KCC2) after a spinal cord injury (SCI) disinhibits motoneurons and dorsal horn interneurons causing spasticity and neuropathic pain, respectively. We showed recently (Bos et al., 2013) that specific activation of 5-HT2A receptors by TCB-2 [(4-bromo-3,6-dimethoxybenzocyclobuten-1-yl)methylamine hydrobromide] upregulates KCC2 function, restores motoneuronal inhibition and reduces SCI-induced spasticity. Here, we tested the potential analgesic effect of TCB-2 on central (thoracic hemisection) and peripheral [spared nerve injury (SNI)] neuropathic pain. We found mechanical and thermal hyperalgesia reduced by an acute administration of TCB-2 in rats with SCI. This analgesic effect was associated with an increase in dorsal horn membrane KCC2 expression and was prevented by pharmacological blockade of KCC2 with an intrathecal injection of DIOA [(dihydroindenyl)oxy]alkanoic acid]. In contrast, the SNI-induced neuropathic pain was not attenuated by TCB-2 although there was a slight increase of membrane KCC2 expression in the dorsal horn ipsilateral to the lesion. Up-regulation of KCC2 function by targeting 5-HT2A receptors, therefore, has therapeutic potential in the treatment of neuropathic pain induced by SCI but not by SNI.
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Affiliation(s)
- Irene Sánchez-Brualla
- Team P3M, Institut de Neurosciences de la Timone, UMR7289, Aix Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France; Department of Cell Biology, Physiology, and Immunology, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Pascale Boulenguez
- Team P3M, Institut de Neurosciences de la Timone, UMR7289, Aix Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Cécile Brocard
- Team P3M, Institut de Neurosciences de la Timone, UMR7289, Aix Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Sylvie Liabeuf
- Team P3M, Institut de Neurosciences de la Timone, UMR7289, Aix Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Annelise Viallat-Lieutaud
- Team P3M, Institut de Neurosciences de la Timone, UMR7289, Aix Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Xavier Navarro
- Department of Cell Biology, Physiology, and Immunology, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Esther Udina
- Department of Cell Biology, Physiology, and Immunology, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Frédéric Brocard
- Team P3M, Institut de Neurosciences de la Timone, UMR7289, Aix Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France.
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Wang Y, Burrell BD. Endocannabinoid-mediated potentiation of nonnociceptive synapses contributes to behavioral sensitization. J Neurophysiol 2018; 119:641-651. [PMID: 29118192 PMCID: PMC5867374 DOI: 10.1152/jn.00092.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 11/02/2017] [Accepted: 11/03/2017] [Indexed: 01/23/2023] Open
Abstract
Endocannabinoids, such as 2-arachidonoyl glycerol (2-AG) and anandamide, can elicit long-term depression of both excitatory and inhibitory synapses. This latter effect will result in disinhibition and would therefore be expected to produce an increase in neural circuit output. However, there have been no examples directly linking endocannabinoid-mediated disinhibition to a change in a functional neurobehavioral circuit. The present study uses the well-characterized central nervous system of the medicinal leech, Hirudo verbana, to examine the functional/behavioral relevance of endocannabinoid modulation of an identified afferent synapse. Bath application of 2-AG potentiates synaptic transmission by pressure-sensitive sensory neurons (P cells) as well as the magnitude of the defensive shortening reflex elicited by P-cell stimulation. This potentiation requires activation of TRPV-like channels. Endocannabinoid/TRPV signaling was found to produce sensitization of the shortening reflex elicited by either direct stimulation of nearby nociceptive afferents (N cells) or noxious stimulation applied to skin several segments away. In both cases, heterosynaptic potentiation of P-cell synapses was observed in parallel with an increase in the magnitude of elicited shortening and both synaptic and behavioral effects were blocked by pharmacological inhibition of 2-AG synthesis or TRPV-like channel activation. Serotonin (5-HT) is known to play a critical role in sensitization in Hirudo and other animals, and the 5-HT2 receptor antagonist ritanserin also blocked behavioral sensitization and the accompanying synaptic potentiation. These findings suggest a novel, endocannabinoid-mediated contribution to behavioral sensitization that may interact with known 5-HT-dependent modulatory processes. NEW & NOTEWORTHY There is considerable interest in the analgesic potential of cannabinoids. However, there is evidence that the cannabinoid system can have both pro- and antinociceptive effects. This study examines how an endogenous cannabinoid transmitter can potentiate nonnociceptive synapses and enhance their capacity to elicit a nocifensive behavioral response.
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Affiliation(s)
- Yanqing Wang
- Division of Basic Biomedical Sciences, Center for Brain and Behavior Research, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota
| | - Brian D Burrell
- Division of Basic Biomedical Sciences, Center for Brain and Behavior Research, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota
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Delis F, Rosko L, Shroff A, Leonard KE, Thanos PK. Oral haloperidol or olanzapine intake produces distinct and region-specific increase in cannabinoid receptor levels that is prevented by high fat diet. Prog Neuropsychopharmacol Biol Psychiatry 2017; 79:268-280. [PMID: 28619471 DOI: 10.1016/j.pnpbp.2017.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/02/2017] [Accepted: 06/12/2017] [Indexed: 10/19/2022]
Abstract
Clinical studies show higher levels of cannabinoid CB1 receptors (CB1R) in the brain of schizophrenic patients while preclinical studies report a significant functional interaction between dopamine D2 receptors and CB1Rs as well as an upregulation of CB1Rs after antipsychotic treatment. These findings prompted us to study the effects of chronic oral intake of a first and a second generation antipsychotic, haloperidol and olanzapine, on the levels and distribution of CB1Rs in the rat brain. Rats consumed either regular chow or high-fat food and drank water, haloperidol drinking solution (1.5mg/kg), or olanzapine drinking solution (10mg/kg) for four weeks. Motor and cognitive functions were tested at the end of treatment week 3 and upon drug discontinuation. Two days after drug discontinuation, rats were euthanized and brains were processed for in vitro receptor autoradiography. In chow-fed animals, haloperidol and olanzapine increased CB1R levels in the basal ganglia and the hippocampus, in a similar, but not identical pattern. In addition, olanzapine had unique effects in CB1R upregulation in higher order cognitive areas, in the secondary somatosensory cortex, in the visual and auditory cortices and the geniculate nuclei, as well as in the hypothalamus. High fat food consumption prevented antipsychotic-induced increase in CB1R levels in all regions examined, with one exception, the globus pallidus, in which they were higher in haloperidol-treated rats. The results point towards the hypothesis that increased CB1R levels could be a confounding effect of antipsychotic medication in schizophrenia that is circumveneted by high fat feeding.
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Affiliation(s)
- Foteini Delis
- Department of Pharmacology, Medical School, University of Ioannina, 45110, Ioannina, Greece
| | - Lauren Rosko
- Georgetown University Medical Center, Georgetown University, Washington, DC, 20007, USA
| | - Aditya Shroff
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, University at Buffalo, Buffalo, NY, 14203, USA
| | - Kenneth E Leonard
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, University at Buffalo, Buffalo, NY, 14203, USA
| | - Panayotis K Thanos
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, University at Buffalo, Buffalo, NY, 14203, USA.
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Das UN. Is There a Role for Bioactive Lipids in the Pathobiology of Diabetes Mellitus? Front Endocrinol (Lausanne) 2017; 8:182. [PMID: 28824543 PMCID: PMC5539435 DOI: 10.3389/fendo.2017.00182] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 07/10/2017] [Indexed: 12/12/2022] Open
Abstract
Inflammation, decreased levels of circulating endothelial nitric oxide (eNO) and brain-derived neurotrophic factor (BDNF), altered activity of hypothalamic neurotransmitters (including serotonin and vagal tone) and gut hormones, increased concentrations of free radicals, and imbalance in the levels of bioactive lipids and their pro- and anti-inflammatory metabolites have been suggested to play a role in diabetes mellitus (DM). Type 1 diabetes mellitus (type 1 DM) is due to autoimmune destruction of pancreatic β cells because of enhanced production of IL-6 and tumor necrosis factor-α (TNF-α) and other pro-inflammatory cytokines released by immunocytes infiltrating the pancreas in response to unknown exogenous and endogenous toxin(s). On the other hand, type 2 DM is due to increased peripheral insulin resistance secondary to enhanced production of IL-6 and TNF-α in response to high-fat and/or calorie-rich diet (rich in saturated and trans fats). Type 2 DM is also associated with significant alterations in the production and action of hypothalamic neurotransmitters, eNO, BDNF, free radicals, gut hormones, and vagus nerve activity. Thus, type 1 DM is because of excess production of pro-inflammatory cytokines close to β cells, whereas type 2 DM is due to excess of pro-inflammatory cytokines in the systemic circulation. Hence, methods designed to suppress excess production of pro-inflammatory cytokines may form a new approach to prevent both type 1 and type 2 DM. Roux-en-Y gastric bypass and similar surgeries ameliorate type 2 DM, partly by restoring to normal: gut hormones, hypothalamic neurotransmitters, eNO, vagal activity, gut microbiota, bioactive lipids, BDNF production in the gut and hypothalamus, concentrations of cytokines and free radicals that results in resetting glucose-stimulated insulin production by pancreatic β cells. Our recent studies suggested that bioactive lipids, such as arachidonic acid, eicosapentaneoic acid, and docosahexaenoic acid (which are unsaturated fatty acids) and their anti-inflammatory metabolites: lipoxin A4, resolvins, protectins, and maresins, may have antidiabetic actions. These bioactive lipids have anti-inflammatory actions, enhance eNO, BDNF production, restore hypothalamic dysfunction, enhance vagal tone, modulate production and action of ghrelin, leptin and adiponectin, and influence gut microbiota that may explain their antidiabetic action. These pieces of evidence suggest that methods designed to selectively deliver bioactive lipids to pancreatic β cells, gut, liver, and muscle may prevent type 1 and type 2 DM.
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Affiliation(s)
- Undurti N. Das
- BioScience Research Centre, Department of Medicine, Gayatri Vidya Parishad Hospital, GVP College of Engineering Campus, Visakhapatnam, India
- UND Life Sciences, Battle Ground, WA, United States
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31
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Araque A, Castillo PE, Manzoni OJ, Tonini R. Synaptic functions of endocannabinoid signaling in health and disease. Neuropharmacology 2017. [PMID: 28625718 DOI: 10.1016/j.neuropharm.2017.06.017] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Endocannabinoids (eCBs) are a family of lipid molecules that act as key regulators of synaptic transmission and plasticity. They are synthetized "on demand" following physiological and/or pathological stimuli. Once released from postsynaptic neurons, eCBs typically act as retrograde messengers to activate presynaptic type 1 cannabinoid receptors (CB1) and induce short- or long-term depression of neurotransmitter release. Besides this canonical mechanism of action, recent findings have revealed a number of less conventional mechanisms by which eCBs regulate neural activity and synaptic function, suggesting that eCB-mediated plasticity is mechanistically more diverse than anticipated. These mechanisms include non-retrograde signaling, signaling via astrocytes, participation in long-term potentiation, and the involvement of mitochondrial CB1. Focusing on paradigmatic brain areas, such as hippocampus, striatum, and neocortex, we review typical and novel signaling mechanisms, and discuss the functional implications in normal brain function and brain diseases. In summary, eCB signaling may lead to different forms of synaptic plasticity through activation of a plethora of mechanisms, which provide further complexity to the functional consequences of eCB signaling. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
| | - Olivier J Manzoni
- Institut National de la Santé et et de la Recherche Médicale U901 Marseille, France, Université de la Méditerranée UMR S901 Aix-Marseille Marseille, France, INMED Marseille, France.
| | - Raffaella Tonini
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, Genova, Italy.
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32
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Kunisawa N, Iha HA, Nomura Y, Onishi M, Matsubara N, Shimizu S, Ohno Y. Serotonergic modulation of nicotine-induced kinetic tremor in mice. J Pharmacol Sci 2017. [DOI: 10.1016/j.jphs.2017.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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Lau BK, Cota D, Cristino L, Borgland SL. Endocannabinoid modulation of homeostatic and non-homeostatic feeding circuits. Neuropharmacology 2017; 124:38-51. [PMID: 28579186 DOI: 10.1016/j.neuropharm.2017.05.033] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/30/2017] [Accepted: 05/31/2017] [Indexed: 02/03/2023]
Abstract
The endocannabinoid system has emerged as a key player in the control of eating. Endocannabinoids, including 2-arachidonoylglycerol (2-AG) and anandamide (AEA), modulate neuronal activity via cannabinoid 1 receptors (CB1Rs) in multiple nuclei of the hypothalamus to induce or inhibit food intake depending on nutritional and hormonal status, suggesting that endocannabinoids may act in the hypothalamus to integrate different types of signals informing about the animal's energy needs. In the mesocorticolimbic system, (endo)cannabinoids modulate synaptic transmission to promote dopamine release in response to palatable food. In addition, (endo)cannabinoids act within the nucleus accumbens to increase food's hedonic impact; although this effect depends on activation of CB1Rs at excitatory, but not inhibitory inputs in the nucleus accumbens. While hyperactivation of the endocannabinoid system is typically associated with overeating and obesity, much evidence has emerged in recent years suggesting a more complicated system than first thought - endocannabinoids promote or suppress feeding depending on cell and input type, or modulation by various neuronal or hormonal signals. This review presents our latest knowledge of the endocannabinoid system in non-homeostatic and homeostatic feeding circuits. In particular, we discuss the functional role and cellular mechanism of action by endocannabinoids within the hypothalamus and mesocorticolimbic system, and how these are modulated by neuropeptide signals related to feeding. In light of recent advances and complexity in the field, we review cannabinoid-based therapeutic strategies for the treatment of obesity and how peripheral restriction of CB1R antagonists may provide a different mechanism of weight loss without the central adverse effects. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Benjamin K Lau
- Department of Physiology and Pharmacology, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB, T2N 4N1, Canada
| | - Daniela Cota
- INSERM U1215, Université de Bordeaux, NeuroCentre Magendie, 146, rue Léo Saignat, 33077 Bordeaux, France
| | - Luigia Cristino
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry of CNR, Viale Campi Flegrei, 34, 80078 Pozzuoli, Napoli, Italy
| | - Stephanie L Borgland
- Department of Physiology and Pharmacology, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB, T2N 4N1, Canada.
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Matsumoto-Makidono Y, Nakayama H, Yamasaki M, Miyazaki T, Kobayashi K, Watanabe M, Kano M, Sakimura K, Hashimoto K. Ionic Basis for Membrane Potential Resonance in Neurons of the Inferior Olive. Cell Rep 2016; 16:994-1004. [PMID: 27425615 DOI: 10.1016/j.celrep.2016.06.053] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 05/04/2016] [Accepted: 06/12/2016] [Indexed: 11/25/2022] Open
Abstract
Some neurons have the ability to enhance output voltage to input current with a preferred frequency, which is called resonance. Resonance is thought to be a basis for membrane potential oscillation. Although ion channels responsible for resonance have been reported, the precise mechanisms by which these channels work remain poorly understood. We have found that resonance is reduced but clearly present in the inferior olivary neurons of Cav3.1 T-type voltage-dependent Ca(2+) channel knockout (KO) mice. The activation of Cav3.1 channels is strongly membrane potential dependent, but less frequency dependent. Residual resonance in Cav3.1 KO mice is abolished by a hyper-polarization-activated cyclic nucleotide-gated (HCN) channel blocker, ZD7288, and is partially suppressed by voltage-dependent K(+) channel blockers. Resonance is inhibited by ZD7288 in wild-type mice and impaired in HCN1 KO mice, suggesting that the HCN1 channel is essential for resonance. The ZD7288-sensitive current is nearly sinusoidal and strongly frequency dependent. These results suggest that Cav3.1 and HCN1 channels act as amplifying and resonating conductances, respectively.
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Affiliation(s)
- Yoshiko Matsumoto-Makidono
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima 734-8551, Japan
| | - Hisako Nakayama
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima 734-8551, Japan
| | - Miwako Yamasaki
- Department of Anatomy, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Taisuke Miyazaki
- Department of Anatomy, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Kazuto Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima 734-8551, Japan.
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35
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Nozaki K, Kubo R, Furukawa Y. Serotonin modulates the excitatory synaptic transmission in the dentate granule cells. J Neurophysiol 2016; 115:2997-3007. [PMID: 26961099 DOI: 10.1152/jn.00064.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/04/2016] [Indexed: 01/23/2023] Open
Abstract
Serotonergic fibers from the raphe nuclei project to the hippocampal formation, the activity of which is known to modulate the inhibitory interneurons in the dentate gyrus. On the other hand, serotonergic modulation of the excitatory synapses in the dentate gyrus is not well examined. In the present study, we examined the effects of 5-HT on the excitatory postsynaptic potentials (EPSPs) in the dentate granule cells evoked by the selective stimulation of the lateral perforant path (LPP), the medial perforant path (MPP), or the mossy cell fibers (MCF). 5-HT depressed the amplitude of unitary EPSPs (uEPSPs) evoked by the stimulation of LPP or MPP, whereas uEPSPs evoked by MCF stimulation were little affected. The effect was partly explained by the decrease of the resting membrane resistance following the activation of 5-HT1A receptors, which was confirmed by computer simulations. We also found that the probability of evoking uEPSP by LPP stimulation but not MPP or MCF stimulation was reduced by 5-HT and that the paired-pulse ratio of LPP-evoked EPSP but not that of MPP- or MCF-evoked ones was increased by 5-HT. These effects were blocked by 5-HT2 antagonist, suggesting that the transmitter release in the LPP-granule cell synapse is inhibited by the activation of 5-HT2 receptors. The present results suggest that 5-HT can modulate the EPSPs in the dentate granule cells by at least two distinct mechanisms.
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Affiliation(s)
- Kanako Nozaki
- Laboratory of Neurobiology, Faculty of Integrated Arts and Sciences, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Japan; and
| | - Reika Kubo
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi, Naka-ku, Hiroshima, Japan
| | - Yasuo Furukawa
- Laboratory of Neurobiology, Faculty of Integrated Arts and Sciences, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Japan; and
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36
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Najar F, Nasehi M, Haeri-Rohani SA, Zarrindast MR. The involvement of medial septum 5-HT1 and 5-HT2 receptors on ACPA-induced memory consolidation deficit: possible role of TRPC3, TRPC6 and TRPV2. J Psychopharmacol 2015; 29:1200-8. [PMID: 26464456 DOI: 10.1177/0269881115609021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present study evaluates the roles of serotonergic receptors of the medial septum on amnesia induced by arachidonylcyclopropylamide (ACPA; as selective cannabinoid CB1 receptor agonist) in adult male Wistar rats. Cannulae were implanted in the medial septum of the brain of the rats. The animals were trained in a passive avoidance learning apparatus, and were tested 24 hours after training for step-through latency. Results indicated that post-training medial septum administration of CP94253 (5-HT1B/1D receptor agonist) and cinancerine (as 5-HT2 receptor antagonist) reduced the step-through latency showing an amnesic response, while GR127935 (5-HT1B/1D receptor antagonist) and αm5htm (as 5-HT2A/2B/2D receptor agonist) did not alter memory consolidation by themselves. On continuing the test, the results showed that CP94253 increased and GR127935 did not alter ACPA (0.02 µg/rat)-induced memory impairment, respectively. Other data indicated that αm5htm induced a modulatory effect, while cinancerine restored ACPA-induced amnesia. Using SKF-96365 (inhibitor of transient receptor potential TRPC3/6 and TRPV2 channels) demonstrated that TRPC3, TRPC3 and TRPV2 channels have a significant role, according to our results.
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Affiliation(s)
- Farzaneh Najar
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad Nasehi
- Cognitive and Neuroscience Research Center (CNRC), Medical Genomics Research Center and School of Advanced Sciences in Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran
| | - Seyed-Ali Haeri-Rohani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad-Reza Zarrindast
- Cognitive and Neuroscience Research Center (CNRC), Medical Genomics Research Center and School of Advanced Sciences in Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran Department of Pharmacology School of Medicine, Tehran University of Basic Sciences, Tehran, Iran Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran Substance Abuse and Dependence Research Center, University of School Welfare and Rehabilitation Sciences, Tehran Iran
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Liu CS, Chau SA, Ruthirakuhan M, Lanctôt KL, Herrmann N. Cannabinoids for the Treatment of Agitation and Aggression in Alzheimer's Disease. CNS Drugs 2015; 29:615-23. [PMID: 26271310 DOI: 10.1007/s40263-015-0270-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) is frequently associated with neuropsychiatric symptoms (NPS) such as agitation and aggression, especially in the moderate to severe stages of the illness. The limited efficacy and high-risk profiles of current pharmacotherapies for the management of agitation and aggression in AD have driven the search for safer pharmacological alternatives. Over the past few years, there has been a growing interest in the therapeutic potential of medications that target the endocannabinoid system (ECS). The behavioural effects of ECS medications, as well as their ability to modulate neuroinflammation and oxidative stress, make targeting this system potentially relevant in AD. This article summarizes the literature to date supporting this rationale and evaluates clinical studies investigating cannabinoids for agitation and aggression in AD. Letters, case studies, and controlled trials from four electronic databases were included. While findings from six studies showed significant benefits from synthetic cannabinoids—dronabinol or nabilone—on agitation and aggression, definitive conclusions were limited by small sample sizes, short trial duration, and lack of placebo control in some of these studies. Given the relevance and findings to date, methodologically rigorous prospective clinical trials are recommended to determine the safety and efficacy of cannabinoids for the treatment of agitation and aggression in dementia and AD.
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Affiliation(s)
- Celina S Liu
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.,Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Room FG 19, Toronto, ON, M4N 3M5, Canada
| | - Sarah A Chau
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.,Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Room FG 19, Toronto, ON, M4N 3M5, Canada
| | - Myuri Ruthirakuhan
- Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Room FG 19, Toronto, ON, M4N 3M5, Canada
| | - Krista L Lanctôt
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.,Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Room FG 19, Toronto, ON, M4N 3M5, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Nathan Herrmann
- Neuropsychopharmacology Research Group, Hurvitz Brain Sciences Program Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Room FG 19, Toronto, ON, M4N 3M5, Canada. .,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
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38
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Viñals X, Moreno E, Lanfumey L, Cordomí A, Pastor A, de La Torre R, Gasperini P, Navarro G, Howell LA, Pardo L, Lluís C, Canela EI, McCormick PJ, Maldonado R, Robledo P. Cognitive Impairment Induced by Delta9-tetrahydrocannabinol Occurs through Heteromers between Cannabinoid CB1 and Serotonin 5-HT2A Receptors. PLoS Biol 2015; 13:e1002194. [PMID: 26158621 PMCID: PMC4497644 DOI: 10.1371/journal.pbio.1002194] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 06/03/2015] [Indexed: 11/19/2022] Open
Abstract
Activation of cannabinoid CB1 receptors (CB1R) by delta9-tetrahydrocannabinol (THC) produces a variety of negative effects with major consequences in cannabis users that constitute important drawbacks for the use of cannabinoids as therapeutic agents. For this reason, there is a tremendous medical interest in harnessing the beneficial effects of THC. Behavioral studies carried out in mice lacking 5-HT2A receptors (5-HT2AR) revealed a remarkable 5-HT2AR-dependent dissociation in the beneficial antinociceptive effects of THC and its detrimental amnesic properties. We found that specific effects of THC such as memory deficits, anxiolytic-like effects, and social interaction are under the control of 5-HT2AR, but its acute hypolocomotor, hypothermic, anxiogenic, and antinociceptive effects are not. In biochemical studies, we show that CB1R and 5-HT2AR form heteromers that are expressed and functionally active in specific brain regions involved in memory impairment. Remarkably, our functional data shows that costimulation of both receptors by agonists reduces cell signaling, antagonist binding to one receptor blocks signaling of the interacting receptor, and heteromer formation leads to a switch in G-protein coupling for 5-HT2AR from Gq to Gi proteins. Synthetic peptides with the sequence of transmembrane helices 5 and 6 of CB1R, fused to a cell-penetrating peptide, were able to disrupt receptor heteromerization in vivo, leading to a selective abrogation of memory impairments caused by exposure to THC. These data reveal a novel molecular mechanism for the functional interaction between CB1R and 5-HT2AR mediating cognitive impairment. CB1R-5-HT2AR heteromers are thus good targets to dissociate the cognitive deficits induced by THC from its beneficial antinociceptive properties.
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MESH Headings
- Amnesia/chemically induced
- Analgesia
- Animals
- Anxiety/chemically induced
- Brain/drug effects
- Brain/metabolism
- Cognition Disorders/chemically induced
- Dimerization
- Dorsal Raphe Nucleus/drug effects
- Dronabinol/adverse effects
- HEK293 Cells
- Humans
- Hypothermia/chemically induced
- Locomotion/drug effects
- Mice, Inbred C57BL
- Mice, Transgenic
- Receptor, Cannabinoid, CB1/drug effects
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Serotonin, 5-HT2A/drug effects
- Receptor, Serotonin, 5-HT2A/metabolism
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Affiliation(s)
- Xavier Viñals
- Neuropharmacology Laboratory, University Pompeu Fabra, Barcelona, Spain
| | - Estefanía Moreno
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Laurence Lanfumey
- CPN, INSERM UMR S894, Université Paris Descartes, UMR S894, Paris, France
| | - Arnau Cordomí
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Antoni Pastor
- Integrative Pharmacology and Systems Neuroscience, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain
| | - Rafael de La Torre
- Integrative Pharmacology and Systems Neuroscience, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain
| | - Paola Gasperini
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Gemma Navarro
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Lesley A. Howell
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Leonardo Pardo
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Carmen Lluís
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Enric I. Canela
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Peter J. McCormick
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Rafael Maldonado
- Neuropharmacology Laboratory, University Pompeu Fabra, Barcelona, Spain
| | - Patricia Robledo
- Neuropharmacology Laboratory, University Pompeu Fabra, Barcelona, Spain
- Integrative Pharmacology and Systems Neuroscience, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain
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39
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Paracetamol potentiates the antidepressant-like and anticompulsive-like effects of fluoxetine. Behav Pharmacol 2015; 26:268-81. [DOI: 10.1097/fbp.0000000000000104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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40
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Impaired fear memory specificity associated with deficient endocannabinoid-dependent long-term plasticity. Neuropsychopharmacology 2014; 39:1685-93. [PMID: 24457285 PMCID: PMC4023141 DOI: 10.1038/npp.2014.15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 01/04/2023]
Abstract
In addition to its central role in learning and memory, N-methyl D-aspartate receptor (NMDAR)-dependent signaling regulates central glutamatergic synapse maturation and has been implicated in schizophrenia. We have transiently induced NMDAR hypofunction in infant mice during postnatal days 7-11, followed by testing fear memory specificity and presynaptic plasticity in the prefrontal cortex (PFC) in adult mice. We show that transient NMDAR hypofunction during early brain development, coinciding with the maturation of cortical plasticity results in a loss of an endocannabinoid (eCB)-mediated form of long-term depression (eCB-LTD) at adult central glutamatergic synapses, while another form of presynaptic long-term depression mediated by the metabotropic glutamate receptor 2/3 (mGluR2/3-LTD) remains intact. Mice with this selective impairment of presynaptic plasticity also showed deficits in fear memory specificity. The observed deficit in cortical presynaptic plasticity may represent a neural maladaptation contributing to network instability and abnormal cognitive functioning.
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Feng CC, Yan XJ, Chen X, Wang EM, Liu Q, Zhang LY, Chen J, Fang JY, Chen SL. Vagal anandamide signaling via cannabinoid receptor 1 contributes to luminal 5-HT modulation of visceral nociception in rats. Pain 2014; 155:1591-1604. [PMID: 24813296 DOI: 10.1016/j.pain.2014.05.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 04/24/2014] [Accepted: 05/02/2014] [Indexed: 12/19/2022]
Abstract
Serotonin (5-HT) plays pivotal roles in the pathogenesis of postinfectious irritable bowel syndrome (PI-IBS), and luminal 5-HT time-dependently modulates visceral nociception. We found that duodenal biopsies from PI-IBS patients exhibited increased 5-HT and decreased anandamide levels and that decreased anandamide was associated with abdominal pain severity, indicating a link between 5-HT and endocannabinoid signaling pathways in PI-IBS. To understand this, we investigated the role of endocannabinoids in 5-HT modulation of visceral nociception in a rat model. Acute intraduodenally applied 5-HT attenuated the visceromotor response (VMR) to colorectal distention, and this was reversed by the cannabinoid receptor 1 (CB1) antagonist AM251. Duodenal anandamide (but not 2-arachidonoylglycerol) content was greatly increased after luminal 5-HT treatment. This effect was abrogated by the 5-HT 3 receptor (5-HT3R) antagonist granisetron, which was luminally delivered to preferentially target vagal terminals. Chemical denervation of vagal afferents blocked 5-HT-evoked antinociception and anandamide release. Chronic luminal 5-HT exposure for 5 days increased baseline VMR and VMR post-5-HT (days 4 and 5). Duodenal levels of anandamide and N-acyl-phosphatidylethanolamine-specific phospholipase D (NAPE-PLD, the anandamide-synthesizing enzyme) protein gradually declined from day 1 to 5. The time-dependent effects of 5-HT were abolished by daily granisetron pretreatment. Daily pretreatment with CB1 agonists or anandamide from day 3 attenuated 5-HT-induced hyperalgesia. These data suggest that vagal 5-HT3R-mediated duodenal anandamide release contributes to acute luminal 5-HT-induced antinociception via CB1 signaling, whereas decreased anandamide is associated with hyperalgesia upon chronic 5-HT treatment. Further understanding of peripheral vagal anandamide signaling may provide insights into the mechanisms underlying 5-HT-related IBS.
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Affiliation(s)
- Chen-Chen Feng
- Department of Gastroenterology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, 145 Middle Shandong Road, Shanghai, China Department of pharmaceutics, Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai, China
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42
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Burattini C, Battistini G, Tamagnini F, Aicardi G. Low-frequency stimulation evokes serotonin release in the nucleus accumbens and induces long-term depression via production of endocannabinoid. J Neurophysiol 2014; 111:1046-55. [DOI: 10.1152/jn.00498.2013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The nucleus accumbens (NAc), a major component of the mesolimbic system, is involved in the mediation of reinforcing and addictive properties of many dependence-producing drugs. Glutamatergic synapses within the NAc can express plasticity, including a form of endocannabinoid (eCB)-long-term depression (LTD). Recent evidences demonstrate cross talk between eCB signaling pathways and those of other receptor systems, including serotonin (5-HT); the extensive colocalization of CB1 and 5-HT receptors within the NAc suggests the potential for interplay between them. In the present study, we found that 20-min low-frequency (4 Hz) stimulation (LFS-4Hz) of glutamatergic afferences in rat brain slices induces a novel form of eCB-LTD in the NAc core, which requires 5-HT2 and CB1 receptor activation and L-type voltage-gated Ca2+ channel opening. Moreover, we found that exogenous 5-HT application (5 μM, 20 min) induces an analogous LTD (5-HT-LTD) at the same synapses, requiring the activation of the same receptors and the opening of the same Ca2+ channels; LFS-4Hz-LTD and 5-HT-LTD were mutually occlusive. Present results suggest that LFS-4Hz induces the release of 5-HT, which acts at 5-HT2 postsynaptic receptors, increasing Ca2+ influx through L-type voltage-gated channels and 2-arachidonoylglycerol production and release; the eCB travels retrogradely and binds to presynaptic CB1 receptors, causing a long-lasting decrease of glutamate release, resulting in LTD. These observations might be helpful to understand the neurophysiological mechanisms underlying drug addiction, major depression, and other psychiatric disorders characterized by dysfunction of 5-HT neurotransmission in the NAc.
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Affiliation(s)
- Costanza Burattini
- Department for Life Quality Studies, University of Bologna, Bologna, Italy; and
| | - Giulia Battistini
- Department for Life Quality Studies, University of Bologna, Bologna, Italy; and
| | - Francesco Tamagnini
- Department for Life Quality Studies, University of Bologna, Bologna, Italy; and
| | - Giorgio Aicardi
- Department for Life Quality Studies, University of Bologna, Bologna, Italy; and
- Interdepartmental Center “Luigi Galvani” for the Study of Biophysics, Bioinformatics and Biocomplexity, University of Bologna, Bologna, Italy
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43
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5HT(1B) receptor-mediated pre-synaptic depression of excitatory inputs to the rat lateral habenula. Neuropharmacology 2014; 81:153-65. [PMID: 24508708 DOI: 10.1016/j.neuropharm.2014.01.046] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 01/06/2014] [Accepted: 01/27/2014] [Indexed: 01/23/2023]
Abstract
Accumulating lines of evidence indicate that the lateral habenula (LHb), which reciprocally interacts with raphe nuclei (RN), displays hyperactivity including synaptic potentiation of excitatory inputs to the LHb during a depressed state. Despite the potential importance of glutamatergic excitatory synapses in depression-like behavior, modulation of these LHb synapses by monoamines such as serotonin (5HT) is not fully understood at the cellular and molecular level. Therefore, we used whole cell voltage-clamp recording to examine the molecular mechanisms by which 5HT modulates glutamatergic transmission in the LHb. The present study provides the first evidence that glutamatergic transmission of LHb synapses is inhibited by activation of the 5HT(1B) receptor at the pre-synapse in both acute depression (5HT-AD) and long-term depression (5HT-LTD). We further show that 5HT-AD results from the activation of Shaker-type K(+) channels whereas 5HT-LTD depends on inhibition of the adenylyl cyclase-cAMP (AC-cAMP) pathway with an increase in pre-synaptic Ca(2+) release from ryanodine-sensitive internal stores in an NO-dependent manner.
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44
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Gong CL, Leung YM, Wang MR, Lin NN, Lee TJF, Kuo JS. Neurochemicals involved in medullary control of common carotid blood flow. Curr Neuropharmacol 2014; 11:513-20. [PMID: 24403875 PMCID: PMC3763759 DOI: 10.2174/1570159x113119990044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 01/22/2013] [Accepted: 07/17/2013] [Indexed: 11/22/2022] Open
Abstract
The common carotid artery (CCA) supplies intra- and extra-cranial vascular beds. An area in the medulla controlling CCA blood flow is defined as the dorsal facial area (DFA) by Kuo et al. in 1987. In the DFA, presynaptic nitrergic and/or glutamatergic fibers innervate preganglionic nitrergic and/or cholinergic neurons which give rise to the preganglionic fibers of the parasympathetic 7th and 9th cranial nerves. Released glutamate from presynaptic nitrergic and/or glutamatergic fibers can activate N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors on preganglionic nitrergic and/or cholinergic neurons. By modulating this glutamate release, several neurochemicals including serotonin, arginine, nitric oxide, nicotine, choline and ATP in the DFA regulate CCA blood flow. Understanding the neurochemical regulatory mechanisms can provide important insights of the physiological roles of the DFA, and may help develop therapeutic strategies for diseases involving CCA blood flow, such as migraine, hypertensive disease, Alzheimer’s disease and cerebral ischemic stroke.
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Affiliation(s)
- Chi-Li Gong
- Department of Physiology, School of Medicine, China Medical University, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, School of Medicine, China Medical University, Taiwan; ; Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taiwan
| | - Ming-Ren Wang
- Yuhing Junior College of Health Care and Management, Kaohsiung, Taiwan
| | - Nai-Nu Lin
- Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Tony Jer-Fu Lee
- Neuro-Medical Scientific Center and Center for Vascular Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan; ; Department of Medical Research, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
| | - Jon-Son Kuo
- Neuro-Medical Scientific Center and Center for Vascular Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan; ; Department of Medical Research, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan; ; Institute of Pharmacology and Toxicology, Tzu Chi University, Hualien, Taiwan
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KANO M. Control of synaptic function by endocannabinoid-mediated retrograde signaling. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2014; 90:235-250. [PMID: 25169670 PMCID: PMC4237895 DOI: 10.2183/pjab.90.235] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 05/30/2014] [Indexed: 06/03/2023]
Abstract
Since the first reports in 2001, great advances have been made towards the understanding of endocannabinoid-mediated synaptic modulation. Electrophysiological studies have revealed that one of the two major endocannabinoids, 2-arachidonoylglycerol (2-AG), is produced from membrane lipids upon postsynaptic Ca(2+) elevation and/or activation of Gq/11-coupled receptors, and released from postsynaptic neurons. The released 2-AG then acts retrogradely onto presynaptic cannabinoid CB1 receptors and induces suppression of neurotransmitter release either transiently or persistently. These forms of 2-AG-mediated retrograde synaptic modulation are functional throughout the brain. The other major endocannabinoid, anandamide, mediates a certain form of endocannabinoid-mediated long-term depression (LTD). Anandamide also functions as an agonist for transient receptor potential vanilloid receptor type 1 (TRPV1) and mediates endocannabinoid-independent and TRPV1-dependent forms of LTD. It has also been demonstrated that the endocannabinoid system itself is plastic, which can be either up- or down-regulated by experimental or environmental conditions. In this review, I will make an overview of the mechanisms underlying endocannabinoid-mediated synaptic modulation.
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Affiliation(s)
- Masanobu KANO
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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46
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Austgen JR, Kline DD. Endocannabinoids blunt the augmentation of synaptic transmission by serotonin 2A receptors in the nucleus tractus solitarii (nTS). Brain Res 2013; 1537:27-36. [PMID: 24041777 DOI: 10.1016/j.brainres.2013.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 08/06/2013] [Accepted: 09/09/2013] [Indexed: 12/21/2022]
Abstract
Serotonin (5-Hydroxytryptamine, 5-HT) and the 5-HT2 receptor modulate cardiovascular and autonomic function in part through actions in the nTS, the primary termination and integration point for cardiorespiratory afferents in the brainstem. In other brain regions, 5-HT2 receptors (5-HT2R) modify synaptic transmission directly, as well as through 5-HT2AR-induced endocannabinoid release. This study examined the role of 5-HT2AR as well as their interaction with endocannabinoids on neurotransmission in the nucleus tractus solitarii (nTS). Excitatory postsynaptic currents (EPSCs) in monosynaptic nTS neurons were recorded in the horizontal brainstem slice during activation and blockade of 5-HT2ARs. 5-HT2AR activation augmented solitary tract (TS) evoked EPSC amplitude whereas 5-HT2AR blockade depressed TS-EPSC amplitude at low and high TS stimulation rates. The 5-HT2AR-induced increase in neurotransmission was reduced by endocannabinoid receptor block and increased endogenous endocannabinoids in the synaptic cleft during high frequency, but not low, TS stimulation. Endocannabinoids did not tonically modify EPSCs. These data suggest 5-HT acting through the 5-HT2AR is an excitatory neuromodulator in the nTS and its effects are modulated by the endocannabinoid system.
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Affiliation(s)
- James R Austgen
- Department of Biomedical Sciences & Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Drive, Columbia, MO 65211, USA
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47
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Iremonger KJ, Wamsteeker Cusulin JI, Bains JS. Changing the tune: plasticity and adaptation of retrograde signals. Trends Neurosci 2013; 36:471-9. [PMID: 23706151 DOI: 10.1016/j.tins.2013.04.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/18/2013] [Accepted: 04/18/2013] [Indexed: 11/25/2022]
Abstract
Retrograde signaling is a fundamental means by which neurons communicate. The acceptance of this statement has required a revision of how we view transmission and storage of information at the synapse. Although there is a substantial body of literature on the diverse molecules that serve as retrograde signals, less is known about how retrograde signal capacity can be modified. Is retrograde signaling plastic? How does this plasticity manifest? Are there behavioral correlates that may bias a neuron towards 'changing its tune', retrogradely speaking, of course? Here, we review recent findings that retrograde signaling is a highly labile process that adds additional layers of complexity that must be untangled to understand information processing in the nervous system.
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Affiliation(s)
- Karl J Iremonger
- Centre for Neuroendocrinology and Department of Physiology, University of Otago, PO Box 913, Dunedin 9054, New Zealand
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48
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Cachope R. Functional diversity on synaptic plasticity mediated by endocannabinoids. Philos Trans R Soc Lond B Biol Sci 2013; 367:3242-53. [PMID: 23108543 DOI: 10.1098/rstb.2011.0386] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Endocannabinoids (eCBs) act as modulators of synaptic transmission through activation of a number of receptors, including, but not limited to, cannabinoid receptor 1 (CB1). eCBs share CB1 receptors as a common target with Δ(9)-tetrahydrocannabinol (THC), the main psychoactive ingredient in marijuana. Although THC has been used for recreational and medicinal purposes for thousands of years, little was known about its effects at the cellular level or on neuronal circuits. Identification of CB1 receptors and the subsequent development of its specific ligands has therefore enhanced our ability to study and bring together a substantial amount of knowledge regarding how marijuana and eCBs modify interneuronal communication. To date, the eCB system, composed of cannabinoid receptors, ligands and the relevant enzymes, is recognized as the best-described retrograde signalling system in the brain. Its impact on synaptic transmission is widespread and more diverse than initially thought. The aim of this review is to succinctly present the most common forms of eCB-mediated modulation of synaptic transmission, while also illustrating the multiplicity of effects resulting from specializations of this signalling system at the circuital level.
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Affiliation(s)
- Roger Cachope
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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49
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Fluoxetine (prozac) and serotonin act on excitatory synaptic transmission to suppress single layer 2/3 pyramidal neuron-triggered cell assemblies in the human prefrontal cortex. J Neurosci 2013; 32:16369-78. [PMID: 23152619 DOI: 10.1523/jneurosci.2618-12.2012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Selective serotonin reuptake inhibitors are the most widely prescribed drugs targeting the CNS with acute and chronic effects in cognitive, emotional and behavioral processes. This suggests that microcircuits of the human cerebral cortex are powerfully modulated by selective serotonin reuptake inhibitors, however, direct measurements of serotonergic regulation on human synaptic interactions are missing. Using multiple whole-cell patch-clamp recordings from neurons in acute cortical slices derived from nonpathological human samples of the prefrontal cortex, we show that neuronal assemblies triggered by single action potentials of individual neurons in the human cortex are suppressed by therapeutic doses of fluoxetine (Prozac). This effect is boosted and can be mimicked by physiological concentrations of serotonin through 5HT-2A and 5HT-1A receptors. Monosynaptic excitatory connections from pyramidal cells to interneurons were suppressed by application of serotonin leaving the monosynaptic output of GABAergic cells unaffected. Changes in failure rate, in paired-pulse ratio, and in the coefficient of variation of the amplitude of EPSPs suggest a presynaptic action of serotonin. In conclusion, activation of neuronal assemblies, which were suggested as building blocks of high order cognitive processes, are effectively downregulated by the acute action of selective serotonin reuptake inhibitors or serotonin at the site of pyramidal output in human microcircuits.
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Cholinergic coordination of presynaptic and postsynaptic activity induces timing-dependent hippocampal synaptic plasticity. J Neurosci 2012; 32:12337-48. [PMID: 22956824 DOI: 10.1523/jneurosci.2129-12.2012] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Correlated presynaptic and postsynaptic activity is the key factor in inducing Hebbian plasticity and memory. However, little is known about the physiological events that could mediate such coordination. Correlated cholinergic input induces spike timing-dependent plasticity-like hippocampal synaptic plasticity. Cholinergic receptors are localized to both presynaptic and postsynaptic glutamatergic sites and thus have the potential to coordinate presynaptic and postsynaptic activity to induce plasticity. By directly monitoring presynaptic and postsynaptic activities with genetically encoded calcium indicators in mouse septohippocampal cocultures, we found interactive but independent presynaptic and postsynaptic modulations in the cholinergic-dependent synaptic plasticity. Neither presynaptic nor postsynaptic modulation alone is sufficient, but instead a coordinated modulation at both sites is required to induce the plasticity. Therefore, we propose that correlated cholinergic input can coordinate presynaptic and postsynaptic activities to induce timing-dependent synaptic plasticity, providing a novel mechanism by which neuromodulators precisely modulate network activity and plasticity with high efficiency and temporal precision.
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