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Rabbani M, Ghannadi A, Malekian N. Evaluation of the effect of Cyperus rotundus L. in scopolamine-induced learning deficit in mice. Adv Biomed Res 2014; 3:217. [PMID: 25371874 PMCID: PMC4219216 DOI: 10.4103/2277-9175.143293] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 02/26/2013] [Indexed: 11/13/2022] Open
Abstract
Background: Cyperus rotundus L. was used in traditional Iranian medicine to treat memory and cognition disorders. The present study was aimed at investigating the effect of the extract and essential oil of C. rotundus on memory dysfunction. Materials and Methods: Cognition was evaluated using the object recognition task that was composed of a square wooden open field box with different shape objects. The test was consisted of three sections: 15 min exploration, first trial for 12 min and second one for 5 min. In the second trial the difference in exploration between a previously seen object and novel one, was considered as an index of memory performance (recognition index). Memory deficit was induced by scopolamine (0.5 mg/kg) before injection of plant extracts and essential oil. Results: Rivastigmine at 0.6 mg/kg reversed the scopolamine induced memory dysfunction in mice (P < 0.05). On the contrary, neither the hydroalcholic extracts (100, 200, 400 mg/kg) nor the polyphenolic extract (50, 100, 200 mg/kg) and essential oil (10, 20, 40 mg/kg) of C. rotundus produced significant improvement of memory dysfunction. The fact that rivastigmine reversed the scopolamine-induced memory dysfunction confirms the validity of this memory paradigm. Conclusion: Using the current method of the memory evaluation, none of the tested doses of the plant extract or essential oil changed the memory status of the animals, indicating either a lack of effective ingredient or unsuitable method for evaluation.
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Affiliation(s)
- Mohammed Rabbani
- Department of Pharmacology, School of Pharmacy and Pharmaceutical Sciences and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Alireza Ghannadi
- Department of Pharmacognosy, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nahid Malekian
- Department of Pharmacology, School of Pharmacy and Pharmaceutical Sciences and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
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Draycott B, Loureiro M, Ahmad T, Tan H, Zunder J, Laviolette SR. Cannabinoid transmission in the prefrontal cortex bi-phasically controls emotional memory formation via functional interactions with the ventral tegmental area. J Neurosci 2014; 34:13096-109. [PMID: 25253856 PMCID: PMC6608340 DOI: 10.1523/jneurosci.1297-14.2014] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 08/15/2014] [Accepted: 08/15/2014] [Indexed: 01/01/2023] Open
Abstract
Disturbances in cortical cannabinoid CB1 receptor signaling are well established correlates of various neuropsychiatric disorders, including depression and schizophrenia. Importantly, the ability of cannabinoid transmission to modulate emotional processing is functionally linked to interactions with subcortical DA systems. While considerable evidence demonstrates that CB1 receptor-mediated modulation of emotional processing and related behaviors follows a biphasic functional curve, little is known regarding how CB1 signaling within cortical networks may interact with subcortical DAergic systems involved in emotional behavior regulation. Using a combination of in vivo electrophysiological recordings and behavioral pharmacology in rats, we investigated the relationship between mPFC cannabinoid transmission, fear memory formation, and subcortical DA neuron activity patterns. We report that direct intra-mPFC CB1 activation biphasically modulates spontaneous, subcortical VTA DA neuron activity in a dose-dependent fashion; while lower doses of a CB1 receptor agonist, WIN 55,212-2, significantly increased spontaneous firing and bursting rates of VTA DA neurons, higher doses strongly inhibited spontaneous DA neuron activity. Remarkably, this same dose-related functional difference was observed with the regulation of fear-related emotional memory formation. Thus, lower levels of CB1 activation potentiated the emotional salience of normally subthreshold fear memory, whereas higher levels completely blocked fear memory acquisition. Furthermore, while the potentiation of subthreshold fear memory salience was blocked by DA receptor antagonism, CB1-mediated blunting of suprathreshold fear memory was rescued by intra-VTA administration of a GABAB receptor antagonist, demonstrating that reversal of GABAergic inhibitory mechanisms in the VTA can reverse the inhibitory influence of intra-PFC CB1 transmission on mesolimbic DA activity.
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Affiliation(s)
| | - Michael Loureiro
- Addiction Research Group, Departments of Anatomy and Cell Biology
| | - Tasha Ahmad
- Addiction Research Group, Departments of Anatomy and Cell Biology
| | - Huibing Tan
- Addiction Research Group, Departments of Anatomy and Cell Biology
| | - Jordan Zunder
- Addiction Research Group, Departments of Anatomy and Cell Biology
| | - Steven R Laviolette
- Addiction Research Group, Departments of Anatomy and Cell Biology, Department of Psychiatry, and Department of Psychology, Schulich School of Medicine and Dentistry. University of Western Ontario, London, Ontario, Canada N6A 5C1
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Rubino T, Parolaro D. Cannabis abuse in adolescence and the risk of psychosis: a brief review of the preclinical evidence. Prog Neuropsychopharmacol Biol Psychiatry 2014; 52:41-4. [PMID: 23916409 DOI: 10.1016/j.pnpbp.2013.07.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/17/2013] [Accepted: 07/23/2013] [Indexed: 01/16/2023]
Abstract
Epidemiological studies suggest that Cannabis use during adolescence confers an increased risk for developing psychotic symptoms later in life. However, despite their interest, the epidemiological data are not conclusive, due to their heterogeneity; thus modeling the adolescent phase in animals is useful for investigating the impact of Cannabis use on deviations of adolescent brain development that might confer a vulnerability to later psychotic disorders. Although scant, preclinical data seem to support the presence of impaired social behaviors, cognitive and sensorimotor gating deficits as well as psychotic-like signs in adult rodents after adolescent cannabinoid exposure, clearly suggesting that this exposure may trigger a complex behavioral phenotype closely resembling a schizophrenia-like disorder. Similar treatments performed at adulthood were not able to produce such phenotype, thus pointing to a vulnerability of the adolescent brain towards cannabinoid exposure. The neurobiological substrate of the adolescent vulnerability is still largely unknown and experimental studies need to elucidate the cellular and molecular mechanism underlying these effects. However, the few data available seem to suggest that heavy adolescent exposure to cannabinoids is able to modify neuronal connectivity in specific brain areas long after the end of the treatment. This is likely due to disruption of maturational events within the endocannabinoid system during adolescence that in turn impact on the correct neuronal refinement peculiar of the adolescent brain, thus leading to altered adult brain functionality and behavior.
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Affiliation(s)
- T Rubino
- Department of Theoretical and Applied Sciences, Biomedical Research Division, University of Insubria, via Manara 7, 21052 Busto Arsizio VA, Italy
| | - D Parolaro
- Department of Theoretical and Applied Sciences, Biomedical Research Division, University of Insubria, via Manara 7, 21052 Busto Arsizio VA, Italy.
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54
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Jacobus J, Squeglia LM, Infante MA, Bava S, Tapert SF. White matter integrity pre- and post marijuana and alcohol initiation in adolescence. Brain Sci 2014; 3:396-414. [PMID: 23914300 PMCID: PMC3728679 DOI: 10.3390/brainsci3010396] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Characterizing the effects of alcohol and marijuana use on adolescent brain development is important for understanding potential alterations in neurodevelopment. Several cross sectional studies have identified group differences in white matter integrity after initiation of heavy alcohol and marijuana use, however none have explored white matter trajectories in adolescents pre- and post initiation of use, particularly for marijuana users. This study followed 16 adolescents with minimal alcohol and marijuana use at ages 16–18 over three years. At follow-up, teens were 19–22 years old; half of the participants initiated heavy alcohol use and half initiated heavy alcohol and marijuana use. Repeated-measures ANOVA revealed 20 clusters in association and projection fibers tracts (p < 0.01) in which a group by time interaction was found. Most consistently, white matter integrity (i.e., fractional anisotropy) decreased for those who initiated both heavy alcohol and marijuana use over the follow-up interval. No effect of time or change in white matter integrity was seen for those who initiated alcohol use only in the majority of clusters. In most regions, at the baseline time point, teens who would later initiate both alcohol and marijuana use demonstrated white matter integrity greater than or equal to teens that initiated alcohol use only. Findings suggest poorer tissue integrity associated with combined initiation of heavy alcohol and marijuana use in late adolescence. While pre-existing differences may also be related to likelihood of substance use, the present data suggest an effect on tissue integrity for these teens transitioning to combined alcohol and marijuana use in later adolescence.
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Affiliation(s)
- Joanna Jacobus
- VA San Diego Healthcare System Psychology Service (116B), 3350 La Jolla Village Drive, San Diego, CA 92126, USA; E-Mails: (J.J.); (S.B.)
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive (0603), La Jolla, CA 92093, USA; E-Mails: (L.M.S.); (M.A.I.)
| | - Lindsay M. Squeglia
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive (0603), La Jolla, CA 92093, USA; E-Mails: (L.M.S.); (M.A.I.)
| | - M. Alejandra Infante
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive (0603), La Jolla, CA 92093, USA; E-Mails: (L.M.S.); (M.A.I.)
- San Diego Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California, 6363 Alvarado Court, Suite 103, San Diego, CA 92120, USA
| | - Sunita Bava
- VA San Diego Healthcare System Psychology Service (116B), 3350 La Jolla Village Drive, San Diego, CA 92126, USA; E-Mails: (J.J.); (S.B.)
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive (0603), La Jolla, CA 92093, USA; E-Mails: (L.M.S.); (M.A.I.)
| | - Susan F. Tapert
- VA San Diego Healthcare System Psychology Service (116B), 3350 La Jolla Village Drive, San Diego, CA 92126, USA; E-Mails: (J.J.); (S.B.)
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive (0603), La Jolla, CA 92093, USA; E-Mails: (L.M.S.); (M.A.I.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-858-552-7563; Fax: +1-858-642-6340
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Cannabinoid receptor activation prevents the effects of chronic mild stress on emotional learning and LTP in a rat model of depression. Neuropsychopharmacology 2014; 39:919-33. [PMID: 24141570 PMCID: PMC3924526 DOI: 10.1038/npp.2013.292] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 10/08/2013] [Accepted: 10/16/2013] [Indexed: 12/17/2022]
Abstract
Most psychiatric disorders are characterized by emotional memory or learning disturbances. Chronic mild stress (CMS) is a common animal model for stress-induced depression. Here we examined whether 3 days of treatment using the CB1/2 receptor agonist WIN55,212-2 could ameliorate the effects of CMS on emotional learning (ie, conditioned avoidance and extinction), long-term potentiation (LTP) in the hippocampal-accumbens pathway, and depression-like symptoms (ie, coping with stress behavior, anhedonia, and weight changes). We also examined whether the ameliorating effects of WIN55,212-2 on behavior and physiology after CMS are mediated by CB1 and glucocorticoid receptors (GRs). Rats were exposed to CMS or handled on days 1-21. The agonist WIN55,212-2 or vehicle were administered on days 19-21 (IP; 0.5 mg/kg) and behavioral and electrophysiological measures were taken on days 23 and 28. The CB1 receptor antagonist AM251 (IP; 0.3 mg/kg) or the GR antagonist RU-38486 (IP; 10 mg/kg) were co-administered with WIN55,212-2. Our results show that CMS significantly modified physiological and behavioral reactions, as observed by the impairment in avoidance extinction and LTP in the hippocampal-accumbens pathway, and the alterations in depression-like symptoms, such as coping with stress behavior, weight gain, and sucrose consumption. The most significant effect observed in this study was that 3 days of WIN55,212-2 administration prevented the CMS-induced alterations in emotional memory (ie, extinction) and plasticity. This effect was mediated by CB1 receptors as the CB1 receptor antagonist AM251 prevented the ameliorating effects of WIN55,212-2 on extinction and LTP. The GR antagonist RU-38486 also prevented the CMS-induced alterations in extinction and plasticity, and when co-administered with WIN55,212-2, the preventive effects after CMS were maintained. The findings suggest that enhancing cannabinoid signaling could represent a novel approach to the treatment of cognitive deficits that accompany stress-related depression.
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56
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Greydanus DE, Hawver EK, Greydanus MM, Merrick J. Marijuana: current concepts(†). Front Public Health 2013; 1:42. [PMID: 24350211 PMCID: PMC3859982 DOI: 10.3389/fpubh.2013.00042] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 09/23/2013] [Indexed: 12/12/2022] Open
Abstract
Marijuana (cannabis) remains a controversial drug in the twenty-first century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis (pot) use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the twenty-first century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public that is often confused by a media-driven, though false message and promise of benign pot consumption.
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Affiliation(s)
- Donald E Greydanus
- Department of Pediatric and Adolescent Medicine, Western Michigan University School of Medicine , Kalamazoo, MI , USA
| | - Elizabeth K Hawver
- Department of Pediatric and Adolescent Medicine, Western Michigan University School of Medicine , Kalamazoo, MI , USA
| | - Megan M Greydanus
- Department of Pediatric and Adolescent Medicine, Western Michigan University School of Medicine , Kalamazoo, MI , USA
| | - Joav Merrick
- National Institute of Child Health and Human Development , Jerusalem , Israel ; Health Services, Division for Intellectual and Developmental Disabilities, Ministry of Social Affairs and Social Services , Jerusalem , Israel ; Division of Pediatrics, Hadassah Hebrew University Medical Center, Mt. Scopus Campus , Jerusalem , Israel ; Kentucky Children's Hospital, University of Kentucky College of Medicine , Lexington, KY , USA
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57
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Cannabinoids ameliorate impairments induced by chronic stress to synaptic plasticity and short-term memory. Neuropsychopharmacology 2013; 38:1521-34. [PMID: 23426383 PMCID: PMC3682147 DOI: 10.1038/npp.2013.51] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Repeated stress is one of the environmental factors that precipitates and exacerbates mental illnesses like depression and anxiety as well as cognitive impairments. We have previously shown that cannabinoids can prevent the effects of acute stress on learning and memory. Here we aimed to find whether chronic cannabinoid treatment would alleviate the long-term effects of exposure to chronic restraint stress on memory and plasticity as well as on behavioral and neuroendocrine measures of anxiety and depression. Late adolescent rats were exposed to chronic restraint stress for 2 weeks followed each day by systemic treatment with vehicle or with the CB1/2 receptor agonist WIN55,212-2 (1.2 mg/kg). Thirty days after the last exposure to stress, rats demonstrated impaired long-term potentiation (LTP) in the ventral subiculum-nucleus accumbens (NAc) pathway, impaired performance in the prefrontal cortex (PFC)-dependent object-recognition task and the hippocampal-dependent spatial version of this task, increased anxiety levels, and significantly reduced expression of glucocorticoid receptors (GRs) in the amygdala, hippocampus, PFC, and NAc. Chronic WIN55,212-2 administration prevented the stress-induced impairment in LTP levels and in the spatial task, with no effect on stress-induced alterations in unconditioned anxiety levels or GR levels. The CB1 antagonist AM251 (0.3 mg/kg) prevented the ameliorating effects of WIN55,212-2 on LTP and short-term memory. Hence, the beneficial effects of WIN55,212-2 on memory and plasticity are mediated by CB1 receptors and are not mediated by alterations in GR levels in the brain areas tested. Our findings suggest that cannabinoid receptor activation could represent a novel approach to the treatment of cognitive deficits that accompany a variety of stress-related neuropsychiatric disorders.
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58
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Crane NA, Schuster RM, Fusar-Poli P, Gonzalez R. Effects of cannabis on neurocognitive functioning: recent advances, neurodevelopmental influences, and sex differences. Neuropsychol Rev 2013; 23:117-37. [PMID: 23129391 PMCID: PMC3593817 DOI: 10.1007/s11065-012-9222-1] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 10/22/2012] [Indexed: 12/19/2022]
Abstract
Decades of research have examined the effects of cannabis on neurocognition. Recent advances in this field provide us with a better understanding of how cannabis use influences neurocognition both acutely (during intoxication) and non-acutely (after acute effects subside). Evidence of problems with episodic memory is one of the most consistent findings reported; however, several other neurocognitive domains appear to be adversely affected by cannabis use under various conditions. There is significant variability in findings across studies, thus a discussion of potential moderators is increasingly relevant. The purpose of this review was to 1) provide an update on research of cannabis' acute and non-acute effects on neurocognition, with a focus on findings since 2007 and 2) suggest and discuss how neurodevelopmental issues and sex differences may influence cannabis effects on neurocognition. Finally we discuss how future investigations may lead to better understanding of the complex interplay among cannabis, stages of neurodevelopment, and sex on neurocognitive functioning.
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Affiliation(s)
| | | | - Paolo Fusar-Poli
- Department of Psychosis Studies, Institute of Psychiatry, King’s College London
| | - Raul Gonzalez
- Department of Psychology, Florida International University
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59
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Schulz S, Becker T, Nagel U, von Ameln-Mayerhofer A, Koch M. Chronic co-administration of the cannabinoid receptor agonist WIN55,212-2 during puberty or adulthood reverses 3,4 methylenedioxymetamphetamine (MDMA)-induced deficits in recognition memory but not in effort-based decision making. Pharmacol Biochem Behav 2013; 106:91-100. [DOI: 10.1016/j.pbb.2013.03.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/15/2013] [Accepted: 03/19/2013] [Indexed: 11/30/2022]
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Abstract
Investigating the effects of cannabis use on memory function appears challenging. While early observational investigations aimed to elucidate the longer-term effects of cannabis use on memory function in humans, findings remained equivocal and pointed to a pattern of interacting factors impacting on the relationship between cannabis use and memory function, rather than a simple direct effect of cannabis. Only recently, a clearer picture of the chronic and acute effects of cannabis use on memory function has emerged once studies have controlled for potential confounding factors and started to investigate the acute effects of delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), the main ingredients in the extract of the cannabis plant in pharmacological challenge experiments. Relatively consistent findings have been reported regarding the acute impairments induced by a single dose of Δ9-THC on verbal and working memory. It is unclear whether they may persist beyond the intoxication state. In the long-term, these impairments seem particularly likely to manifest and may also persist following abstinence if regular and heavy use of cannabis strains high in Δ9-THC is started at an early age. Although still at an early stage, studies that employed advanced neuroimaging techniques have started to model the neural underpinnings of the effects of cannabis use and implicate a network of functional and morphological alterations that may moderate the effects of cannabis on memory function. Future experimental and epidemiological studies that take into consideration individual differences, particularly previous cannabis history and demographic characteristics, but also the precise mixture of the ingredients of the consumed cannabis are necessary to clarify the magnitude and the mechanisms by which cannabis-induced memory impairments occur and to elucidate underlying neurobiological mechanisms.
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Affiliation(s)
- Tabea Schoeler
- Department of Psychosis Studies, King's College London, Institute of Psychiatry, London, UK
| | - Sagnik Bhattacharyya
- Department of Psychosis Studies, King's College London, Institute of Psychiatry, London, UK
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61
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Predator threat stress promotes long lasting anxiety-like behaviors and modulates synaptophysin and CB1 receptors expression in brain areas associated with PTSD symptoms. Neurosci Lett 2012. [PMID: 23178193 DOI: 10.1016/j.neulet.2012.11.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Several studies have suggested that changes in hippocampal, prefrontal cortex and amygdaloid complex function are associated with the main symptoms of Posttraumatic Stress Disorder (PTSD). Predator exposure can mimic some aspects of PSTD such as hyperarousal and chronic anxiety. However, little is known about the neural substrate involved in this model. Synaptophysin (SYP) expression has been used to evaluate synaptic plastic changes while cannabinoids have emerged as a therapeutic target for the treatment of stress- and anxiety-related disorders. The present work evaluated whether the long lasting behavioral effects evoked by predator exposure are associated to long-term changes in the expression of the Cannabinoid receptor 1 (CB1) and the synaptic protein SYP in brain areas related to the genesis of PTSD symptoms (frontal cortex, hippocampus and amygdaloid complex). Male Wistar rats were exposed to a live or a dummy cat and seven days later submitted to the elevated plus maze test. To explore possible neurobiological mechanisms involved in these effects, CB1 receptor and SYP mRNA expression were measured in the hippocampus, frontal cortex and amygdaloid complex. Single predator exposure promoted long-lasting anxiogenic effects. Seven days after predator threat CB1 mRNA expression was down regulated in the frontal cortex and amygdaloid complex while SYP gene was up regulated in the amygdaloid complex. Our results suggested that predator exposure causes long-lasting anxiogenic effects associated with hyperactivation of amygdaloid complex and modulation of CB1 receptor in brain areas related to PTSD symptoms.
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Pedroza-Llinás R, Méndez-Díaz M, Ruiz-Contreras AE, Prospéro-García Ó. CB1 receptor activation in the nucleus accumbens core impairs contextual fear learning. Behav Brain Res 2012; 237:141-7. [PMID: 23018128 DOI: 10.1016/j.bbr.2012.09.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/14/2012] [Accepted: 09/17/2012] [Indexed: 01/01/2023]
Abstract
Contextual fear conditioning is a behavioral model in which a subject learns that a specific context is predictive of danger occurrence. There is evidence suggesting an important role for both the nucleus accumbens (NAc) and the endocannabinoid system in contextual fear conditioning formation. The purpose of this study was to assess whether endocannabinoids within the NAc modulate fear memory formation. Pre-training anandamide (AEA) infusions into the NAc core (NAcC) of male Wistar rats decreased freezing behavior in the contextual fear-conditioning paradigm, as evaluated 24h after training. However, AEA did not induce any effect on the cued fear-conditioning paradigm. Likewise, AEA infusions into the NAc shell did not interfere with the contextual fear learning. AEA's effect was blocked when co-infused with AM251 (CB1R inverse agonist). Post-training AEA infusions failed to exert an effect on contextual conditioning. These results suggest a cannabinergic regulation in the NAcC of the acquisition of contextual fear conditioning.
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Affiliation(s)
- Rodrigo Pedroza-Llinás
- Grupo de Neurociencias, Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, México, DF, Mexico
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63
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Caballero A, Tseng KY. Association of Cannabis Use during Adolescence, Prefrontal CB1 Receptor Signaling, and Schizophrenia. Front Pharmacol 2012; 3:101. [PMID: 22654759 PMCID: PMC3361072 DOI: 10.3389/fphar.2012.00101] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 05/05/2012] [Indexed: 01/09/2023] Open
Abstract
The cannabinoid receptor 1 (CB1R) is the G-protein coupled receptor responsible for the majority of the endocannabinoid signaling in the human brain. It is widely distributed in the limbic system, basal ganglia, and cerebellum, which are areas responsible for cognition, memory, and motor control. Because of this widespread distribution, it is not surprising that drugs that activate CB1R have expected behavioral outcomes consistent with dysregulated signaling from these areas (e.g., memory loss, cognitive deficits, etc). In the context of this review, we present evidence for the role of CB1R signaling in the prefrontal cortex (PFC), an area involved in executive functions, with emphasis on the developmental regulation of CB1R signaling in the acquisition of mature PFC function. We further hypothesize how alterations in CB1R signaling specifically during adolescent maturation might confer liability to psychiatric disorders.
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Affiliation(s)
- Adriana Caballero
- Department of Cellular and Molecular Pharmacology, RFUMS/The Chicago Medical School North Chicago, IL, USA
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