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Rodrigues RS, Moreira JB, Mateus JM, Barateiro A, Paulo SL, Vaz SH, Lourenço DM, Ribeiro FF, Soares R, Loureiro-Campos E, Bielefeld P, Sebastião AM, Fernandes A, Pinto L, Fitzsimons CP, Xapelli S. Cannabinoid type 2 receptor inhibition enhances the antidepressant and proneurogenic effects of physical exercise after chronic stress. Transl Psychiatry 2024; 14:170. [PMID: 38555299 PMCID: PMC10981758 DOI: 10.1038/s41398-024-02877-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 03/05/2024] [Accepted: 03/14/2024] [Indexed: 04/02/2024] Open
Abstract
Chronic stress is a major risk factor for neuropsychiatric conditions such as depression. Adult hippocampal neurogenesis (AHN) has emerged as a promising target to counteract stress-related disorders given the ability of newborn neurons to facilitate endogenous plasticity. Recent data sheds light on the interaction between cannabinoids and neurotrophic factors underlying the regulation of AHN, with important effects on cognitive plasticity and emotional flexibility. Since physical exercise (PE) is known to enhance neurotrophic factor levels, we hypothesised that PE could engage with cannabinoids to influence AHN and that this would result in beneficial effects under stressful conditions. We therefore investigated the actions of modulating cannabinoid type 2 receptors (CB2R), which are devoid of psychotropic effects, in combination with PE in chronically stressed animals. We found that CB2R inhibition, but not CB2R activation, in combination with PE significantly ameliorated stress-evoked emotional changes and cognitive deficits. Importantly, this combined strategy critically shaped stress-induced changes in AHN dynamics, leading to a significant increase in the rates of cell proliferation and differentiation of newborn neurons, overall reduction in neuroinflammation, and increased hippocampal levels of BDNF. Together, these results show that CB2Rs are crucial regulators of the beneficial effects of PE in countering the effects of chronic stress. Our work emphasises the importance of understanding the mechanisms behind the actions of cannabinoids and PE and provides a framework for future therapeutic strategies to treat stress-related disorders that capitalise on lifestyle interventions complemented with endocannabinoid pharmacomodulation.
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Affiliation(s)
- R S Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Université de Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
| | - J B Moreira
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - J M Mateus
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - A Barateiro
- Central Nervous System, blood and peripheral inflammation, Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - S L Paulo
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - S H Vaz
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - D M Lourenço
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - F F Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - R Soares
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - E Loureiro-Campos
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - P Bielefeld
- Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - A M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - A Fernandes
- Central Nervous System, blood and peripheral inflammation, Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - L Pinto
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - C P Fitzsimons
- Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - S Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
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van der Heijden AR, Houben T. Lipids in major depressive disorder: new kids on the block or old friends revisited? Front Psychiatry 2023; 14:1213011. [PMID: 37663599 PMCID: PMC10469871 DOI: 10.3389/fpsyt.2023.1213011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/04/2023] [Indexed: 09/05/2023] Open
Abstract
Major depressive disorder (MDD) is a psychiatric mood disorder that results in substantial functional impairment and is characterized by symptoms such as depressed mood, diminished interest, impaired cognitive function, and vegetative symptoms such as disturbed sleep. Although the exact etiology of MDD is unclear, several underlying mechanisms (disturbances in immune response and/or stress response) have been associated with its development, with no single mechanism able to account for all aspects of the disorder. Currently, about 1 in 3 patients are resistant to current antidepressant therapies. Providing an alternative perspective on MDD could therefore pave the way for new, unexplored diagnostic and therapeutic solutions. The central nervous system harbors an enormous pool of lipids and lipid intermediates that have been linked to a plethora of its physiological functions. The aim of this review is therefore to provide an overview of the implications of lipids in MDD and highlight certain MDD-related underlying mechanisms that involve lipids and/or their intermediates. Furthermore, we will also focus on the bidirectional relationship between MDD and the lipid-related disorders obesity and type 2 diabetes.
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Affiliation(s)
| | - Tom Houben
- Department of Genetics and Cell Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, Netherlands
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3
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Hyperbaric Oxygenation Prevents Loss of Immature Neurons in the Adult Hippocampal Dentate Gyrus Following Brain Injury. Int J Mol Sci 2023; 24:ijms24054261. [PMID: 36901691 PMCID: PMC10002298 DOI: 10.3390/ijms24054261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/09/2023] [Accepted: 02/14/2023] [Indexed: 02/25/2023] Open
Abstract
A growing body of evidence suggests that hyperbaric oxygenation (HBO) may affect the activity of adult neural stem cells (NSCs). Since the role of NSCs in recovery from brain injury is still unclear, the purpose of this study was to investigate the effects of sensorimotor cortex ablation (SCA) and HBO treatment (HBOT) on the processes of neurogenesis in the adult dentate gyrus (DG), a region of the hippocampus that is the site of adult neurogenesis. Ten-week-old Wistar rats were divided into groups: Control (C, intact animals), Sham control (S, animals that underwent the surgical procedure without opening the skull), SCA (animals in whom the right sensorimotor cortex was removed via suction ablation), and SCA + HBO (operated animals that passed HBOT). HBOT protocol: pressure applied at 2.5 absolute atmospheres for 60 min, once daily for 10 days. Using immunohistochemistry and double immunofluorescence labeling, we show that SCA causes significant loss of neurons in the DG. Newborn neurons in the subgranular zone (SGZ), inner-third, and partially mid-third of the granule cell layer are predominantly affected by SCA. HBOT decreases the SCA-caused loss of immature neurons, prevents reduction of dendritic arborization, and increases proliferation of progenitor cells. Our results suggest a protective effect of HBO by reducing the vulnerability of immature neurons in the adult DG to SCA injury.
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Bayram P, Billur D, Kizil S, Caliskan H, Can B. Alterations in hippocampal neurogenesis and hippocampal insulin signaling pathway in rat with metabolic syndrome. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2022; 25:1308-1316. [PMID: 36474571 PMCID: PMC9699955 DOI: 10.22038/ijbms.2022.64917.14295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 09/14/2022] [Indexed: 01/25/2023]
Abstract
OBJECTIVES We aimed to examine the level of hippocampal neurogenesis, and assess learning and anxiety and the level of some proteins involving insulin signaling pathways in rats with Metabolic Syndrome (MetS); and to reveal the relationship among them. MATERIALS AND METHODS Totally, 30 Wistar-albino rats were used. The rats were divided into three groups: Control, MetS, and MetS+Ins. Immunohistochemical staining was performed to evaluate the levels of neurogenesis markers; Doublecortin (DCX), Neuronal-Differentiation-1 (NeuroD1), Ki67, and Neuronal nuclear protein (NeuN). Then, cleaved caspase-3 and TUNEL labeling were performed to detect the level of apoptosis. Additionally, behavior tests were performed to evaluate the learning-memory levels and anxiety-like behaviors. Insulin, Insulin Receptor (IR), Insulin Receptor Substrate (IRS2), glucose transporter (GLUT)-3, and GLUT4 protein expression levels were analyzed to evaluate the possible changes in the insulin signaling pathway. RESULTS An increase in anxiety with memory deficiency was observed in MetS. In the hippocampus of MetS, an increase was detected in the level of apoptosis, whereas a decrease was detected in the expression level of the neurogenesis marker. Insulin secretion and IR levels decreased in hippocampal neurons. We observed that GLUT3 and GLUT4 levels increased because of the non-activated insulin signaling pathway. CONCLUSION We think that the insulin signaling pathway may have an effect on the decreased neurogenesis in the MetS group. So, the evaluation of the Mitogen-activated protein kinase (MAPK) pathway and the investigation of the effect of endoplasmic reticulum stress on this pathway will be among the targets of our future studies.
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Affiliation(s)
- Pinar Bayram
- Kafkas University, Faculty of Medicine, Department of Histology and Embryology, Kars, Turkey,Corresponding author: Pınar Bayram. Kafkas University, Medical Faculty, Department of Histology and Embryology, 36100, Kars, Turkey. Tel: +905439189849;
| | - Deniz Billur
- Ankara University, Faculty of Medicine, Department of Histology and Embryology, Ankara, Turkey
| | - Sule Kizil
- Lokman Hekim University, Faculty of Medicine, Department of Histology and Embryology, Ankara, Turkey
| | - Hasan Caliskan
- Balıkesir University, Faculty of Medicine, Department of Physiology, Balıkesir, Turkey
| | - Belgin Can
- Ankara University, Faculty of Medicine, Department of Histology and Embryology, Ankara, Turkey
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Schuele LL, Schuermann B, Bilkei-Gorzo A, Gorgzadeh S, Zimmer A, Leidmaa E. Regulation of adult neurogenesis by the endocannabinoid-producing enzyme diacylglycerol lipase alpha (DAGLa). Sci Rep 2022; 12:633. [PMID: 35022487 PMCID: PMC8755832 DOI: 10.1038/s41598-021-04600-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 11/22/2021] [Indexed: 01/09/2023] Open
Abstract
The endocannabinoid system modulates adult hippocampal neurogenesis by promoting the proliferation and survival of neural stem and progenitor cells (NSPCs). This is demonstrated by the disruption of adult neurogenesis under two experimental conditions: (1) NSPC-specific deletion of cannabinoid receptors and (2) constitutive deletion of the enzyme diacylglycerol lipase alpha (DAGLa) which produces the endocannabinoid 2-arachidonoylglycerol (2-AG). However, the specific cell types producing 2-AG relevant to neurogenesis remain unknown. Here we sought to identify the cellular source of endocannabinoids in the subgranular zone of the dentate gyrus (DG) in hippocampus, an important neurogenic niche. For this purpose, we used two complementary Cre-deleter mouse strains to delete Dagla either in neurons, or in astroglia and NSPCs. Surprisingly, neurogenesis was not altered in mice bearing a deletion of Dagla in neurons (Syn-Dagla KO), although neurons are the main source for the endocannabinoids in the brain. In contrast, a specific inducible deletion of Dagla in NPSCs and astrocytes (GLAST-CreERT2-Dagla KO) resulted in a strongly impaired neurogenesis with a 50% decrease in proliferation of newborn cells. These results identify Dagla in NSPCs in the DG or in astrocytes as a prominent regulator of adult hippocampal neurogenesis. We also show a reduction of Daglb expression in GLAST-CreERT2-Dagla KO mice, which may have contributed to the neurogenesis phenotype.
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Affiliation(s)
- Lena-Louise Schuele
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Britta Schuermann
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Sara Gorgzadeh
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany.
| | - Este Leidmaa
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, Building 76, 53127, Bonn, Germany
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Gallego-Landin I, García-Baos A, Castro-Zavala A, Valverde O. Reviewing the Role of the Endocannabinoid System in the Pathophysiology of Depression. Front Pharmacol 2021; 12:762738. [PMID: 34938182 PMCID: PMC8685322 DOI: 10.3389/fphar.2021.762738] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 11/11/2021] [Indexed: 01/04/2023] Open
Abstract
Major depressive disorder is a high-impact, debilitating disease and it is currently considered the most prevalent mental illness. It is associated with disability, as well as increased morbidity and mortality. Despite its significant repercussions in our society, its exact pathophysiology remains unclear and therefore, available antidepressant treatment options are limited and, in some cases, ineffective. In the past years, research has focused on the development of a multifactorial theory of depression. Simultaneously, evidence supporting the role of the endocannabinoid system in the neurobiology of neuropsychiatric diseases has emerged. Studies have shown that the endocannabinoid system strongly impacts neurotransmission, and the neuroendocrine and neuroimmune systems, which are known to be dysfunctional in depressive patients. Accordingly, common antidepressants were shown to have a direct impact on the expression of cannabinoid receptors throughout the brain. Therefore, the relationship between the endocannabinoid system and major depressive disorder is worth consideration. Nevertheless, most studies focus on smaller pieces of what is undoubtedly a larger mosaic of interdependent processes. Therefore, the present review summarizes the existing literature regarding the role of the endocannabinoid system in depression aiming to integrate this information into a holistic picture for a better understanding of the relationship between the two.
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Affiliation(s)
- Ines Gallego-Landin
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Alba García-Baos
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Adriana Castro-Zavala
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Olga Valverde
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
- Neuroscience Research Programme, IMIM-Hospital del Mar Research Institute, Barcelona, Spain
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Visvanathar R, Papanikolaou M, Nôga DA, Pádua-Reis M, Tort ABL, Blunder M. Hippocampal Cb 2 receptors: an untold story. Rev Neurosci 2021; 33:413-426. [PMID: 34717053 DOI: 10.1515/revneuro-2021-0109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 10/01/2021] [Indexed: 12/13/2022]
Abstract
The field of cannabinoid research has been receiving ever-growing interest. Ongoing debates worldwide about the legislation of medical cannabis further motivates research into cannabinoid function within the central nervous system (CNS). To date, two well-characterized cannabinoid receptors exist. While most research has investigated Cb1 receptors (Cb1Rs), Cb2 receptors (Cb2Rs) in the brain have started to attract considerable interest in recent years. With indisputable evidence showing the wide-distribution of Cb2Rs in the brain of different species, they are no longer considered just peripheral receptors. However, in contrast to Cb1Rs, the functionality of central Cb2Rs remains largely unexplored. Here we review recent studies on hippocampal Cb2Rs. While conflicting results about their function have been reported, we have made significant progress in understanding the involvement of Cb2Rs in modulating cellular properties and network excitability. Moreover, Cb2Rs have been shown to be expressed in different subregions of the hippocampus, challenging our prior understanding of the endocannabinoid system. Although more insight into their functional roles is necessary, we propose that targeting hippocampal Cb2Rs may offer novel therapies for diseases related to memory and adult neurogenesis deficits.
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Affiliation(s)
- Robin Visvanathar
- Behavioral Neurophysiology, Department of Neuroscience, Biomedical Center, Uppsala University, Husargatan 3, 751 23, Uppsala, Sweden
| | - Maria Papanikolaou
- Behavioral Neurophysiology, Department of Neuroscience, Biomedical Center, Uppsala University, Husargatan 3, 751 23, Uppsala, Sweden
| | - Diana Aline Nôga
- Behavioral Neurophysiology, Department of Neuroscience, Biomedical Center, Uppsala University, Husargatan 3, 751 23, Uppsala, Sweden
| | - Marina Pádua-Reis
- Behavioral Neurophysiology, Department of Neuroscience, Biomedical Center, Uppsala University, Husargatan 3, 751 23, Uppsala, Sweden
| | | | - Martina Blunder
- Behavioral Neurophysiology, Department of Neuroscience, Biomedical Center, Uppsala University, Husargatan 3, 751 23, Uppsala, Sweden
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Valeri A, Mazzon E. Cannabinoids and Neurogenesis: The Promised Solution for Neurodegeneration? Molecules 2021; 26:molecules26206313. [PMID: 34684894 PMCID: PMC8541184 DOI: 10.3390/molecules26206313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/14/2021] [Accepted: 10/16/2021] [Indexed: 01/02/2023] Open
Abstract
The concept of neurons as irreplaceable cells does not hold true today. Experiments and evidence of neurogenesis, also, in the adult brain give hope that some compounds or drugs can enhance this process, helping to reverse the outcomes of diseases or traumas that once were thought to be everlasting. Cannabinoids, both from natural and artificial origins, already proved to have several beneficial effects (e.g., anti-inflammatory, anti-oxidants and analgesic action), but also capacity to increase neuronal population, by replacing the cells that were lost and/or regenerate a damaged nerve cell. Neurogenesis is a process which is not highly represented in literature as neuroprotection, though it is as important as prevention of nervous system damage, because it can represent a possible solution when neuronal death is already present, such as in neurodegenerative diseases. The aim of this review is to resume the experimental evidence of phyto- and synthetic cannabinoids effects on neurogenesis, both in vitro and in vivo, in order to elucidate if they possess also neurogenetic and neurorepairing properties.
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Li C, Shi J, Sun J, Shi Y, Jia H. Cannabinoid receptor 2 deficiency enhances isoflurane-induced spatial cognitive impairment in adult mice by affecting neuroinflammation, neurogenesis and neuroplasticity. Exp Ther Med 2021; 22:908. [PMID: 34257720 PMCID: PMC8243338 DOI: 10.3892/etm.2021.10340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/21/2021] [Indexed: 12/15/2022] Open
Abstract
Isoflurane (Iso) is a commonly used inhalational anesthetic and is associated with the incidence of postoperative cognitive dysfunction (POCD). Cannabinoid receptor 2 (CB2R) was previously reported to have a promising neuroprotective function in cases of POCD, but the specific mechanisms have remained to be fully explored. The aim of the present study was to investigate the effect of CB2R deficiency on spatial cognitive performance in adult mice exposed to Iso. A total of 20 adult CB2R knockout (KO) and 20 wild-type (WT) mice were exposed to Iso (1.4% in oxygen for 4 h) or 100% oxygen. The Morris water maze (MWZ) test was performed 10 days after Iso exposure. Immunofluorescence staining and reverse transcription-quantitative PCR were performed to assess the expression of microglial marker ionized calcium-binding adaptor molecule-1 (Iba1) and the mRNA expression levels of microglial phenotype markers (M1: Interleukin-6, tumor necrosis factor-α, inducible nitric oxide synthase; M2: Chitinase-3 like protein) in the hippocampus. Changes in hippocampal neurogenesis and neuroplasticity were assessed by 5-bromodeoxyuridine (BrdU) immunostaining and Golgi staining. Compared with control mice, WT Iso-exposed mice had impaired spatial performance in the MWZ test. Furthermore, hippocampal Iba1 immunoreactivity and the number of microglial branches were notably increased in Iso-exposed WT mice. This was paralleled by significant upregulation of M1-associated markers and downregulation of M2-associated markers in the hippocampus. An obviously reduced number of BrdU+ neurons and decreased spine density were observed in WT Iso-exposed mice compared with control mice. Of note, CB2R deficiency exacerbated the spatial cognition impairment induced by Iso in the MWZ test. The alterations in the activation, morphology and M1 polarization of microglia, the number of BrdU+ neurons and spine density were more pronounced in CB2R-deficient Iso-exposed KO mice than in WT Iso-exposed mice. These results suggested that CB2R has a crucial role in Iso-induced cognitive impairment, which may be related to changes in hippocampal neuroinflammation, neurogenesis and neuroplasticity.
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Affiliation(s)
- Chao Li
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jingpu Shi
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jiaguang Sun
- Department of Anesthesiology, Xingtai People's Hospital, Xintai, Hebei 054001, P.R. China
| | - Yuanyuan Shi
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Huiqun Jia
- Department of Anesthesiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
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Abstract
The endocannabinoid system (ECS) is a highly versatile signaling system within the nervous system. Despite its widespread localization, its functions within the context of distinct neural processes are very well discernable and specific. This is remarkable, and the question remains as to how such specificity is achieved. One key player in the ECS is the cannabinoid type 1 receptor (CB1), a G protein-coupled receptor characterized by the complexity of its cell-specific expression, cellular and subcellular localization, and its adaptable regulation of intracellular signaling cascades. CB1 receptors are involved in different synaptic and cellular plasticity processes and in the brain's bioenergetics in a context-specific manner. CB2 receptors are also important in several processes in neurons, glial cells, and immune cells of the brain. As polymorphisms in ECS components, as well as external impacts such as stress and metabolic challenges, can both lead to dysregulated ECS activity and subsequently to possible neuropsychiatric disorders, pharmacological intervention targeting the ECS is a promising therapeutic approach. Understanding the neurobiology of cannabinoid receptor signaling in depth will aid optimal design of therapeutic interventions, minimizing unwanted side effects.
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Affiliation(s)
- Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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11
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Luján MÁ, Valverde O. The Pro-neurogenic Effects of Cannabidiol and Its Potential Therapeutic Implications in Psychiatric Disorders. Front Behav Neurosci 2020; 14:109. [PMID: 32676014 PMCID: PMC7333542 DOI: 10.3389/fnbeh.2020.00109] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/02/2020] [Indexed: 12/20/2022] Open
Abstract
During the last decades, researchers have investigated the functional relevance of adult hippocampal neurogenesis in normal brain function as well as in the pathogenesis of diverse psychiatric conditions. Although the underlying mechanisms of newborn neuron differentiation and circuit integration have yet to be fully elucidated, considerable evidence suggests that the endocannabinoid system plays a pivotal role throughout the processes of adult neurogenesis. Thus, synthetic, and natural cannabinoid compounds targeting the endocannabinoid system have been utilized to modulate the proliferation and survival of neural progenitor cells and immature neurons. Cannabidiol (CBD), a constituent of the Cannabis Sativa plant, interacts with the endocannabinoid system by inhibiting fatty acid amide hydrolase (FAAH) activity (the rate-limiting enzyme for anandamide hydrolysis), allosterically modulating CB1 and CB2 receptors, and activating components of the "extended endocannabinoid system." Congruently, CBD has shown prominent pro-neurogenic effects, and, unlike Δ9-tetrahydrocannabinol, it has the advantage of being devoid of psychotomimetic effects. Here, we first review pre-clinical studies supporting the facilitating effects of CBD on adult hippocampal neurogenesis and available data disclosing cannabinoid mechanisms by which CBD can induce neural proliferation and differentiation. We then review the respective implications for its neuroprotective, anxiolytic, anti-depressant, and anti-reward actions. In conclusion, accumulating evidence reveals that, in rodents, adult neurogenesis is key to understand the behavioral manifestation of symptomatology related to different mental disorders. Hence, understanding how CBD promotes adult neurogenesis in rodents could shed light upon translational therapeutic strategies aimed to ameliorate psychiatric symptomatology dependent on hippocampal function in humans.
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Affiliation(s)
- Miguel Á. Luján
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Olga Valverde
- Neurobiology of Behaviour Research Group (GReNeC—NeuroBio), Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
- Neuroscience Research Programme, IMIM-Hospital del Mar Research Institute, Barcelona, Spain
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Meccariello R. Endocannabinoid System in Health and Disease: Current Situation and Future Perspectives. Int J Mol Sci 2020; 21:ijms21103549. [PMID: 32443408 PMCID: PMC7278997 DOI: 10.3390/ijms21103549] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
- Rosaria Meccariello
- Department of Movement Sciences and Wellbeing, University of Naples "Parthenope", Via Medina 40, 80133 Naples, Italy
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Endocannabinoid system and adult neurogenesis: a focused review. Curr Opin Pharmacol 2019; 50:25-32. [PMID: 31864101 DOI: 10.1016/j.coph.2019.11.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/22/2019] [Accepted: 11/05/2019] [Indexed: 11/24/2022]
Abstract
The endocannabinoid system (eCB) is a ubiquitous lipid signaling system composed of at least two receptors, their endogenous ligands, and the enzymes responsible for their synthesis and degradation. Within the brain, the eCB system is highly expressed in the hippocampus and controls basic biological processes, including neuronal proliferation, migration and differentiation, which are intimately linked with embryonal neurogenesis. Accumulated preclinical evidence has indicated that eCBs play a major role also in regulating adult neurogenesis. Increased cannabinoid receptor activity, either by increased eCB content or by pharmacological blockade of their degradation, produces neurogenic effects alongside rescue of phenotypes in animal models of different psychiatric and neurological disorders. Therefore, in the light of the higher therapeutic potential of adult neurogenesis compared to the embryonic one, here we sought to summarize the most recent evidence pointing towards a neurogenic role for eCBs in the adult brain, both under normal and pathological conditions.
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