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Kouchaeknejad A, Van Der Walt G, De Donato MH, Puighermanal E. Imaging and Genetic Tools for the Investigation of the Endocannabinoid System in the CNS. Int J Mol Sci 2023; 24:15829. [PMID: 37958825 PMCID: PMC10648052 DOI: 10.3390/ijms242115829] [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: 09/15/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
As central nervous system (CNS)-related disorders present an increasing cause of global morbidity, mortality, and high pressure on our healthcare system, there is an urgent need for new insights and treatment options. The endocannabinoid system (ECS) is a critical network of endogenous compounds, receptors, and enzymes that contribute to CNS development and regulation. Given its multifaceted involvement in neurobiology and its significance in various CNS disorders, the ECS as a whole is considered a promising therapeutic target. Despite significant advances in our understanding of the ECS's role in the CNS, its complex architecture and extensive crosstalk with other biological systems present challenges for research and clinical advancements. To bridge these knowledge gaps and unlock the full therapeutic potential of ECS interventions in CNS-related disorders, a plethora of molecular-genetic tools have been developed in recent years. Here, we review some of the most impactful tools for investigating the neurological aspects of the ECS. We first provide a brief introduction to the ECS components, including cannabinoid receptors, endocannabinoids, and metabolic enzymes, emphasizing their complexity. This is followed by an exploration of cutting-edge imaging tools and genetic models aimed at elucidating the roles of these principal ECS components. Special emphasis is placed on their relevance in the context of CNS and its associated disorders.
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Affiliation(s)
| | | | | | - Emma Puighermanal
- Neuroscience Institute, Autonomous University of Barcelona, 08193 Bellaterra, Spain; (A.K.); (G.V.D.W.); (M.H.D.D.)
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2
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Potier M, Maitre M, Leste-Lasserre T, Marsicano G, Chaouloff F, Marighetto A. Age-dependent effects of estradiol on temporal memory: A role for the type 1 cannabinoid receptor? Psychoneuroendocrinology 2023; 148:106002. [PMID: 36521252 DOI: 10.1016/j.psyneuen.2022.106002] [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: 07/20/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
This study investigated in male mice how age modulates the effects of acute 17β-estradiol (E2) on dorsal CA1 (dCA1)-dependent retention of temporal associations, which are critical for declarative memory. E2 was systemically injected to young (3-4 months old) and aged (22-24 months old) adult mice either (i) 1 h before the acquisition of an auditory trace fear conditioning (TFC) procedure allowing the assessment of temporal memory retention 24 h later or (ii) during in vivo electrophysiological recordings of CA3 to dCA1 synaptic efficacy under anesthesia. In young mice, E2 induced parallel dose-dependent reductions in memory and synaptic efficacy, i.e. an impairment in TFC retention and a long-term (NMDA receptor-dependent) depression of dCA1 synaptic efficacy as assessed by field excitatory postsynaptic potentials. In contrast, E2 tended to improved TFC retention whilst failing to change synaptic efficacy in aged mice. Age-dependent effects of E2 treatment were confirmed by immunohistochemical analyses of TFC acquisition-elicited dCA1 Fos activation. Thus, such an activation was respectively reduced and enhanced in young and aged E2-treated mice, compared to vehicle treatments. Hippocampal mRNA expression of estrogen receptors by RT-PCR analyses revealed an age-related increase in each receptor mRNA expression. In keeping with the key role of the endocannabinoid system in memory processes and CA3 to dCA1 synaptic plasticity, we next examined the role of cannabinoid type 1 receptors (CB1-R) in the aforementioned age-dependent effects of E2. Having confirmed that mRNA expression of CB1-R diminishes with age, we then observed that the deleterious effects of E2 on both memory and synaptic efficacy were both prevented by the CB1-R antagonist Rimonabant whilst being absent in CB1-R knock out mice. This study (i) reveals age-dependent effects of acute E2 on temporal memory and CA3 to dCA1 synaptic efficacy and (ii) suggests a key role of CB1-R in mediating E2 deleterious effects in young adulthood. Aging-related reductions in CB1-R might thus underlie E2 paradoxical effects across age.
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Affiliation(s)
- Mylène Potier
- Pathophysiology of Declarative Memory, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France.
| | - Marlène Maitre
- PUMA, INSERM U1215, Neurocentre Magendie, Bordeaux, France
| | | | - Giovanni Marsicano
- Endocannabinoids & NeuroAdaptation, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France
| | - Francis Chaouloff
- Endocannabinoids & NeuroAdaptation, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France.
| | - Aline Marighetto
- Pathophysiology of Declarative Memory, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France
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Palmisano M, Gargano A, Olabiyi BF, Lutz B, Bilkei-Gorzo A. Hippocampal Deletion of CB1 Receptor Impairs Social Memory and Leads to Age-Related Changes in the Hippocampus of Adult Mice. Int J Mol Sci 2022; 24:ijms24010026. [PMID: 36613469 PMCID: PMC9819823 DOI: 10.3390/ijms24010026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/10/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Endocannabinoid system activity declines with age in the hippocampus, along with the density of the cannabinoid receptor type-1 (CB1). This process might contribute to brain ageing, as previous studies showed that the constitutive deletion of the CB1 receptor in mice leads to early onset of memory deficits and histological signs of ageing in the hippocampus including enhanced pro-inflammatory glial activity and reduced neurogenesis. Here we asked whether the CB1 receptor exerts its activity locally, directly influencing hippocampal ageing or indirectly, accelerating systemic ageing. Thus, we deleted the CB1 receptor site-specifically in the hippocampus of 2-month-old CB1flox/flox mice using stereotaxic injections of rAAV-Cre-Venus viruses and assessed their social recognition memory four months later. Mice with hippocampus-specific deletion of the CB1 receptor displayed a memory impairment, similarly as observed in constitutive knockouts at the same age. We next analysed neuroinflammatory changes in the hippocampus, neuronal density and cell proliferation. Site-specific mutant mice had enhanced glial cell activity, up-regulated levels of TNFα in the hippocampus and decreased cell proliferation, specifically in the subgranular zone of the dentate gyrus. Our data indicate that a local activity of the CB1 receptor in the hippocampus is required to maintain neurogenesis and to prevent neuroinflammation and cognitive decline.
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Affiliation(s)
- Michela Palmisano
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53125 Bonn, Germany
| | - Alessandra Gargano
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53125 Bonn, Germany
| | | | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
- Leibniz Institute for Resilience Research (LIR), 55122 Mainz, Germany
| | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, 53125 Bonn, Germany
- Correspondence: ; Tel.: +49-0228-6885-317
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Komorowska-Müller JA, Rana T, Olabiyi BF, Zimmer A, Schmöle AC. Cannabinoid Receptor 2 Alters Social Memory and Microglial Activity in an Age-Dependent Manner. Molecules 2021; 26:5984. [PMID: 34641528 PMCID: PMC8513097 DOI: 10.3390/molecules26195984] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/20/2021] [Accepted: 09/28/2021] [Indexed: 12/18/2022] Open
Abstract
Physiological brain aging is characterized by gradual, substantial changes in cognitive ability, accompanied by chronic activation of the neural immune system. This form of inflammation, termed inflammaging, in the central nervous system is primarily enacted through microglia, the resident immune cells. The endocannabinoid system, and particularly the cannabinoid receptor 2 (CB2R), is a major regulator of the activity of microglia and is upregulated under inflammatory conditions. Here, we elucidated the role of the CB2R in physiological brain aging. We used CB2R-/- mice of progressive ages in a behavioral test battery to assess social and spatial learning and memory. This was followed by detailed immunohistochemical analysis of microglial activity and morphology, and of the expression of pro-inflammatory cytokines in the hippocampus. CB2R deletion decreased social memory in young mice, but did not affect spatial memory. In fact, old CB2R-/- mice had a slightly improved social memory, whereas in WT mice we detected an age-related cognitive decline. On a cellular level, CB2R deletion increased lipofuscin accumulation in microglia, but not in neurons. CB2R-/- microglia showed an increase of activity markers Iba1 and CD68, and minor upregulation in tnfa and il6 expression and downregulation of ccl2 with age. This was accompanied by a change in morphology as CB2R-/- microglia had smaller somas and lower polarity, with increased branching, cell volume, and tree length. We present that CB2Rs are involved in cognition and age-induced microglial activity, but may also be important for microglial activation itself.
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Affiliation(s)
- Joanna Agnieszka Komorowska-Müller
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, 53127 Bonn, Germany; (J.A.K.-M.); (T.R.); (B.F.O.); (A.-C.S.)
- International Max Planck Research School for Brain and Behavior, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Tanushka Rana
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, 53127 Bonn, Germany; (J.A.K.-M.); (T.R.); (B.F.O.); (A.-C.S.)
| | - Bolanle Fatimat Olabiyi
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, 53127 Bonn, Germany; (J.A.K.-M.); (T.R.); (B.F.O.); (A.-C.S.)
| | - Andreas Zimmer
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, 53127 Bonn, Germany; (J.A.K.-M.); (T.R.); (B.F.O.); (A.-C.S.)
| | - Anne-Caroline Schmöle
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, 53127 Bonn, Germany; (J.A.K.-M.); (T.R.); (B.F.O.); (A.-C.S.)
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6
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Carrera J, Tomberlin J, Kurtz J, Karakaya E, Bostanciklioglu M, Albayram O. Endocannabinoid Signaling for GABAergic-Microglia (Mis)Communication in the Brain Aging. Front Neurosci 2021; 14:606808. [PMID: 33613174 PMCID: PMC7887316 DOI: 10.3389/fnins.2020.606808] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/28/2020] [Indexed: 12/11/2022] Open
Abstract
The aging brain seems to be characterized by neuronal loss leading to cognitive decline and progressively worsening symptoms related to neurodegeneration. Also, pro-inflammatory states, if prolonged, may increase neuronal vulnerability via excessive activation of microglia and their pro-inflammatory by-products, which is seen as individuals increase in age. Consequently, microglial activity is tightly regulated by neuron-microglia communications. The endocannabinoid system (ECS) is emerging as a regulator of microglia and the neuronal-microglia communication system. Recently, it has been demonstrated that cannabinoid 1 (CB1) receptor signaling on GABAergic interneurons plays a crucial role in regulating microglial activity. Interestingly, if endocannabinoid signaling on GABAergic neurons are disturbed, the phenotypes mimic central nervous system insult models by activating microglia and leading to accelerated brain aging. Investigating the endocannabinoid receptors, ligands, and genetic deletions yields the potential to understand the communication system and mechanism by which the ECS regulates glial cells and aspects of aging. While there remains much to discover with the ECS, the information gathered and identified already could lead to the development of cell-specific therapeutic interventions that help in reducing the effects of age-related pro-inflammatory states and neurodegeneration.
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Affiliation(s)
- Jorge Carrera
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Jensen Tomberlin
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States.,Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - John Kurtz
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Eda Karakaya
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | | | - Onder Albayram
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, United States.,Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States.,Ralph H. Johnson VA Medical Center, Charleston, SC, United States
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7
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Alami K, Mousavi SY. Afghan Chehelghoza (Pinus gerardiana L.) Pine Nut Diet Enhances the Learning and Memory in Male Rats. NUTRITION AND DIETARY SUPPLEMENTS 2020. [DOI: 10.2147/nds.s278350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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8
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Abstract
Given the aging Baby Boomer generation, changes in cannabis legislation, and the growing acknowledgment of cannabis for its therapeutic potential, it is predicted that cannabis use in the older population will escalate. It is, therefore, important to determine the interaction between the effects of cannabis and aging. The aim of this report is to describe the link between cannabis use and the aging brain. Our review of the literature found few and inconsistent empirical studies that directly address the impact of cannabis use on the aging brain. However, research focused on long-term cannabis use points toward cumulative effects on multimodal systems in the brain that are similarly affected during aging. Specifically, the effects of cannabis and aging converge on overlapping networks in the endocannabinoid, opioid, and dopamine systems that may affect functional decline particularly in the hippocampus and prefrontal cortex, which are critical areas for memory and executive functioning. To conclude, despite the limited current knowledge on the potential interactive effects between cannabis and aging, evidence from the literature suggests that cannabis and aging effects are concurrently present across several neurotransmitter systems. There is a great need for future research to directly test the interactions between cannabis and aging.
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Affiliation(s)
- Hye Bin Yoo
- Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas, USA
| | - Jennifer DiMuzio
- Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas, USA
| | - Francesca M Filbey
- Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas, USA
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9
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Perkins AE, Varlinskaya EI, Deak T. From adolescence to late aging: A comprehensive review of social behavior, alcohol, and neuroinflammation across the lifespan. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2019; 148:231-303. [PMID: 31733665 DOI: 10.1016/bs.irn.2019.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The passage of time dictates the pace at which humans and other organisms age but falls short of providing a complete portrait of how environmental, lifestyle and underlying biological processes contribute to senescence. Two fundamental features of the human experience that change dramatically across the lifespan include social interactions and, for many, patterns of alcohol consumption. Rodent models show great utility for understanding complex interactions among aging, social behavior and alcohol use and abuse, yet little is known about the neural changes in late aging that contribute to the natural decline in social behavior. Here, we posit that aging-related neuroinflammation contributes to the insipid loss of social motivation across the lifespan, an effect that is exacerbated by patterns of repeated alcohol consumption observed in many individuals. We provide a comprehensive review of (i) neural substrates crucial for the expression of social behavior under non-pathological conditions; (ii) unique developmental/lifespan vulnerabilities that may contribute to the divergent effects of low-and high-dose alcohol exposure; and (iii) aging-associated changes in neuroinflammation that may sit at the intersection between social processes and alcohol exposure. In doing so, we provide an overview of correspondence between lifespan/developmental periods between common rodent models and humans, give careful consideration to model systems used to aptly probe social behavior, identify points of coherence between human and animal models, and point toward a multitude of unresolved issues that should be addressed in future studies. Together, the combination of low-dose and high-dose alcohol effects serve to disrupt the normal development and maintenance of social relationships, which are critical for both healthy aging and quality of life across the lifespan. Thus, a more complete understanding of neural systems-including neuroinflammatory processes-which contribute to alcohol-induced changes in social behavior will provide novel opportunities and targets for promoting healthy aging.
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Affiliation(s)
- Amy E Perkins
- Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, Binghamton, NY, United States
| | - Elena I Varlinskaya
- Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, Binghamton, NY, United States
| | - Terrence Deak
- Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, Binghamton, NY, United States.
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10
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de Pablos RM, Espinosa-Oliva AM, Hornedo-Ortega R, Cano M, Arguelles S. Hydroxytyrosol protects from aging process via AMPK and autophagy; a review of its effects on cancer, metabolic syndrome, osteoporosis, immune-mediated and neurodegenerative diseases. Pharmacol Res 2019; 143:58-72. [DOI: 10.1016/j.phrs.2019.03.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/04/2019] [Accepted: 03/06/2019] [Indexed: 12/31/2022]
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11
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Hodges EL, Ashpole NM. Aging circadian rhythms and cannabinoids. Neurobiol Aging 2019; 79:110-118. [PMID: 31035036 DOI: 10.1016/j.neurobiolaging.2019.03.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/11/2019] [Accepted: 03/17/2019] [Indexed: 01/04/2023]
Abstract
Numerous aspects of mammalian physiology exhibit cyclic daily patterns known as circadian rhythms. However, studies in aged humans and animals indicate that these physiological rhythms are not consistent throughout the life span. The simultaneous development of disrupted circadian rhythms and age-related impairments suggests a shared mechanism, which may be amenable to therapeutic intervention. Recently, the endocannabinoid system has emerged as a complex signaling network, which regulates numerous aspects of circadian physiology relevant to the neurobiology of aging. Agonists of cannabinoid receptor-1 (CB1) have consistently been shown to decrease neuronal activity, core body temperature, locomotion, and cognitive function. Paradoxically, several lines of evidence now suggest that very low doses of cannabinoids are beneficial in advanced age. One potential explanation for this phenomenon is that these drugs exhibit hormesis-a biphasic dose-response wherein low doses produce the opposite effects of higher doses. Therefore, it is important to determine the dose-, age-, and time-dependent effects of these substances on the regulation of circadian rhythms and other processes dysregulated in aging. This review highlights 3 fields-biological aging, circadian rhythms, and endocannabinoid signaling-to critically assess the therapeutic potential of endocannabinoid modulation in aged individuals. If the hormetic properties of exogenous cannabinoids are confirmed, we conclude that precise administration of these compounds may bidirectionally entrain central and peripheral circadian clocks and benefit multiple aspects of aging physiology.
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Affiliation(s)
- Erik L Hodges
- Pharmacology Division, Department of BioMolecular Sciences, University of Mississippi School of Pharmacy, Oxford, MS, USA
| | - Nicole M Ashpole
- Pharmacology Division, Department of BioMolecular Sciences, University of Mississippi School of Pharmacy, Oxford, MS, USA.
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12
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Sarne Y. Beneficial and deleterious effects of cannabinoids in the brain: the case of ultra-low dose THC. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2019; 45:551-562. [PMID: 30864864 DOI: 10.1080/00952990.2019.1578366] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This article reviews the neurocognitive advantages and drawbacks of cannabinoid substances, and discusses the possible physiological mechanisms that underlie their dual activity. The article further reviews the neurocognitive effects of ultra-low doses of ∆9-tetrahydrocannabinol (THC; 3-4 orders of magnitude lower than the conventional doses) in mice, and proposes such low doses of THC as a possible remedy for various brain injuries and for the treatment of age-related cognitive decline.
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Affiliation(s)
- Yosef Sarne
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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13
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Reversal of age-related cognitive impairments in mice by an extremely low dose of tetrahydrocannabinol. Neurobiol Aging 2018; 61:177-186. [DOI: 10.1016/j.neurobiolaging.2017.09.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 09/18/2017] [Accepted: 09/23/2017] [Indexed: 01/28/2023]
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Lack of hippocampal CB1 receptor desensitization by Δ(9)-tetrahydrocannabinol in aged mice and by low doses of JZL 184. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:603-12. [PMID: 26984820 DOI: 10.1007/s00210-016-1226-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 03/01/2016] [Indexed: 12/30/2022]
Abstract
Activation of cannabinoid CB1 receptors may offer new therapeutic strategies, but the efficiency of CB1 receptor agonists may be impaired by tolerance development upon prolonged administration. We compared the influence of repeated administration of Δ(9)-tetrahydrocannabinol (THC) 10 mg/kg on the motility and on basal and CB1 receptor-stimulated (35)S-GTPγS binding of adolescent and aged mice. Moreover, we determined the influence of JZL 184 (which inhibits the 2-arachidonoylglycerol, 2-AG, degrading enzyme monoacylglycerol lipase, MAGL) on (35)S-GTPγS binding and 2-AG levels of young adult mice. Mouse motility was tested in the open field. (35)S-GTPγS binding was studied in hippocampal membranes. THC and CP 55,940 were used as cannabinoid agonists in the behavioural and biochemical studies, respectively. 2-AG levels were quantified by liquid chromatography-multiple reaction monitoring. The THC (10 mg/kg)-induced hypomotility was stronger in untreated than in THC-pretreated adolescent mice but similar in both treatment groups of aged mice. Basal and stimulated (35)S-GTPγS binding was decreased in membranes from THC-pretreated adolescent but not affected in membranes from aged mice. Treatment of young adult mice with JZL 184 (4, 10 and 40 mg/kg) for 14 days did not affect basal binding. Stimulated binding tended to be decreased by 25 % only in mice treated with JZL 184 (40 mg/kg). Hippocampal 2-AG level was increased by JZL 184 at 40 and 10 but not affected at 4 mg/kg. In conclusion, CB1 receptor tolerance does not occur in aged mice pretreated with THC and in young adult mice treated with a low dose of the MAGL inhibitor JZL 184.
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Age differences in the role of the cannabinoid type 1 receptor on glutamatergic neurons in habituation and spatial memory acquisition. Life Sci 2015; 138:57-63. [PMID: 25744401 DOI: 10.1016/j.lfs.2015.01.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 01/08/2015] [Accepted: 01/30/2015] [Indexed: 11/21/2022]
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16
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Di Marzo V, Stella N, Zimmer A. Endocannabinoid signalling and the deteriorating brain. Nat Rev Neurosci 2015; 16:30-42. [PMID: 25524120 DOI: 10.1038/nrn3876] [Citation(s) in RCA: 266] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ageing is characterized by the progressive impairment of physiological functions and increased risk of developing debilitating disorders, including chronic inflammation and neurodegenerative diseases. These disorders have common molecular mechanisms that can be targeted therapeutically. In the wake of the approval of the first cannabinoid-based drug for the symptomatic treatment of multiple sclerosis, we examine how endocannabinoid (eCB) signalling controls--and is affected by--normal ageing and neuroinflammatory and neurodegenerative disorders. We propose a conceptual framework linking eCB signalling to the control of the cellular and molecular hallmarks of these processes, and categorize the key components of endocannabinoid signalling that may serve as targets for novel therapeutics.
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Affiliation(s)
- Vincenzo Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Nephi Stella
- 1] Department of Pharmacology, University of Washington. [2] Department of Psychiatry and Behavioral Science, University of Washington, 1959 Pacific Avenue North, Seattle, Washington 98103, USA
| | - Andreas Zimmer
- Institute for Molecular Psychiatry, University of Bonn, Sigmund Freud Straße 25, Bonn 53127, Germany
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Abstract
The physiological and pathophysiological functions of the endocannabinoid system have been studied extensively using transgenic and targeted knockout mouse models. The first gene deletions of the cannabinoid CB(1) receptor were described in the late 1990s, soon followed by CB(2) and FAAH mutations in early 2000. These mouse models helped to elucidate the fundamental role of endocannabinoids as retrograde transmitters in the CNS and in the discovery of many unexpected endocannabinoid functions, for example, in the skin, bone and liver. We now have knockout mouse models for almost every receptor and enzyme of the endocannabinoid system. Conditional mutant mice were mostly developed for the CB(1) receptor, which is widely expressed on many different neurons, astrocytes and microglia, as well as on many cells outside the CNS. These mouse strains include "floxed" CB(1) alleles and mice with a conditional re-expression of CB(1). The availability of these mice made it possible to decipher the function of CB(1) in specific neuronal circuits and cell populations or to discriminate between central and peripheral effects. Many of the genetic mouse models were also used in combination with viral expression systems. The purpose of this review is to provide a comprehensive overview of the existing genetic models and to summarize some of the most important discoveries that were made with these animals.
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MESH Headings
- Amidohydrolases/genetics
- Amidohydrolases/metabolism
- Animals
- Endocannabinoids/genetics
- Endocannabinoids/metabolism
- Gene Deletion
- Gene Expression Regulation
- Genotype
- Humans
- Hydrolysis
- Mice, Knockout
- Mice, Mutant Strains
- Monoacylglycerol Lipases/genetics
- Monoacylglycerol Lipases/metabolism
- Mutation
- Phenotype
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Signal Transduction/genetics
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Affiliation(s)
- Andreas Zimmer
- Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany.
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18
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Loss of CB1 receptors leads to decreased cathepsin D levels and accelerated lipofuscin accumulation in the hippocampus. Mech Ageing Dev 2013; 134:391-9. [PMID: 23954857 DOI: 10.1016/j.mad.2013.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 07/10/2013] [Accepted: 08/03/2013] [Indexed: 02/08/2023]
Abstract
Early onset of age-related changes in the brain of cannabinoid 1 receptor knockout (Cnr1(-/-)) mice suggests that cannabinoid 1 (CB1) receptor activity significantly influences the progression of brain aging. In the present study we show that lack of CB1 receptors leads to a significant increase in lipofuscin accumulation and a reduced expression and activity of cathepsin D, lysosomal protease implicated in the degradation of damaged macromolecules, in the hippocampus of 12-month-old mice. The impaired clearance of damaged macromolecules due to the low cathepsin D levels and not enhanced oxidative stress may be responsible for the lipofuscin accumulation because macromolecule oxidation levels were comparable between the genotypes within the same age group. The altered levels of autophagy markers p62 and LC3-II suggest that autophagy is upregulated in CB1 knockout mice. Increased autophagic flux in the absence of CB1 receptors is probably a compensatory mechanism to partially counteract decreased lysosomal degradation capacity. Together, these results suggest that CB1 receptor activity affects lysosomal activity, degradation of damaged macromolecules and thus it may influence the course and onset of brain aging.
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