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BACKGROUND: Alterations in eating behavior are common in infants with intrauterine growth restriction (IUGR); omega-3 polyunsaturated fatty acids (PUFA) could provide protection. We hypothesized that those born IUGR with a genetic background associated with increased production of omega-3-PUFA will have more adaptive eating behaviors during childhood. METHODS: IUGR/non-IUGR classified infants from MAVAN and GUSTO cohorts were included at the age of 4 and 5 years, respectively. Their parents reported child's eating behaviors using the child eating behavior questionnaire-CEBQ. Based on the GWAS on serum PUFA (Coltell 2020), three polygenic scores were calculated. RESULTS: Significant interactions between IUGR and polygenic score for omega-3-PUFA on emotional overeating (ß = -0.15, P = 0.049 GUSTO) and between IUGR and polygenic score for omega-6/omega-3-PUFA on desire to drink (ß = 0.35, P = 0.044 MAVAN), pro-intake/anti-intake ratio (ß = 0.10, P = 0.042 MAVAN), and emotional overeating (ß = 0.16, P = 0.043 GUSTO) were found. Only in IUGR, a higher polygenic score for omega-3-PUFA associated with lower emotional overeating, while a higher polygenic score for omega-6/omega-3-PUFA ratio was associated with a higher desire to drink, emotional overeating, and pro-intake/anti-intake. CONCLUSION: Only in IUGR, the genetic background for higher omega-3-PUFA is associated with protection against altered eating behavior, while the genetic score for a higher omega-6/omega-3-PUFA ratio is associated with altered eating behavior. IMPACT: A genetic background related to a higher polygenic score for omega-3 PUFA protected infants born IUGR against eating behavior alterations, while a higher polygenic score for omega-6/omega-3 PUFA ratio increased the risk of having eating behavior alterations only in infants born IUGR, irrespective of their adiposity in childhood. Genetic individual differences modify the effect of being born IUGR on eating outcomes, increasing the vulnerability/resilience to eating disorders in IUGR group and likely contributing to their risk for developing metabolic diseases later in life.
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Ácidos Grasos Omega-3 , Retardo del Crecimiento Fetal , Lactante , Femenino , Humanos , Niño , Preescolar , Retardo del Crecimiento Fetal/genética , Conducta Alimentaria , Ácidos Grasos Insaturados , HiperfagiaRESUMEN
Sick animals display drastic changes in their behavioral patterns, including decreased activity, decreased food and water intake, and decreased interest in social interactions. These behaviors, collectively called "sickness behaviors", can be socially modulated. For example, when provided with mating opportunities, males of several species show reduced sickness behaviors. While the behavior is known to change, how the social environment affects neural molecular responses to sickness is not known. Here, we used a species, the zebra finch, Taeniopygia guttata, where males have been shown to decrease sickness behaviors when presented with novel females. Using this paradigm, we obtained samples from three brain regions (the hypothalamus, the bed nucleus of the stria terminalis, and the nucleus taeniae) from lipopolysaccharide (LPS) or control treated males housed under four different social environments. Manipulation of the social environment rapidly changed the strength and co-expression patterns of the neural molecular responses to the immune challenge in all brain regions tested, therefore suggesting that the social environment plays a significant role in determining the neural responses to an infection. In particular, brains of males paired with a novel female showed muted immune responses to LPS, as well as altered synaptic signaling. Neural metabolic activity in response to the LPS challenge was also affected by the social environment. Our results provide new insights into the effects of the social environment on brain responses to an infection, thereby improving our understanding of how the social environment can affect health.
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Hipotálamo , Lipopolisacáridos , Animales , Masculino , Femenino , Lipopolisacáridos/farmacología , Lipopolisacáridos/metabolismo , Hipotálamo/metabolismo , Medio Social , Conducta de Enfermedad , Encéfalo , Conducta SocialRESUMEN
Cannabis use is increasing among some demographics in the United States and is tightly linked to anxiety, trauma, and stress reactivity at the epidemiological and biological level. Stress-coping motives are highly cited reasons for cannabis use. However, with increased cannabis use comes the increased susceptibility for cannabis use disorder (CUD). Indeed, CUD is highly comorbid with posttraumatic stress disorder (PTSD). Importantly, endogenous cannabinoid signaling systems play a key role in the regulation of stress reactivity and anxiety regulation, and preclinical data suggest deficiencies in this signaling system could contribute to the development of stress-related psychopathology. Furthermore, endocannabinoid deficiency states, either pre-existing or induced by trauma exposure, could provide explanatory insights into the high rates of comorbid cannabis use in patients with PTSD. Here we review clinical and preclinical literature related to the cannabis use-PTSD comorbidity, the role of endocannabinoids in the regulation of stress reactivity, and potential therapeutic implications of recent work in this area.
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Abuso de Marihuana , Trastornos por Estrés Postraumático , Comorbilidad , Humanos , Abuso de Marihuana/epidemiología , Abuso de Marihuana/fisiopatología , Abuso de Marihuana/terapia , Trastornos por Estrés Postraumático/epidemiología , Trastornos por Estrés Postraumático/fisiopatología , Trastornos por Estrés Postraumático/terapia , Estados Unidos/epidemiologíaRESUMEN
Over the past decade there has been a surge of interest in the development of endocannabinoid-based therapeutic approaches for the treatment of diverse neuropsychiatric conditions. Although initial preclinical and clinical development efforts focused on pharmacological inhibition of fatty acid amide hydrolase to elevate levels of the endocannabinoid anandamide, more recent efforts have focused on inhibition of monoacylglycerol lipase (MAGL) to enhance signaling of the most abundant and efficacious endocannabinoid ligand, 2-arachidonoylglycerol (2-AG). We review the biochemistry and physiology of 2-AG signaling and preclinical evidence supporting a role for this system in the regulation of anxiety-related outcomes and stress adaptation. We review preclinical evidence supporting MAGL inhibition for the treatment of affective, trauma-related, and stress-related disorders; describe the current state of MAGL inhibitor drug development; and discuss biological factors that could affect MAGL inhibitor efficacy. Issues related to the clinical advancement of MAGL inhibitors are also discussed. We are cautiously optimistic, as the field of MAGL inhibitor development transitions from preclinical to clinical and theoretical to practical, that pharmacological 2-AG augmentation could represent a mechanistically novel therapeutic approach for the treatment of affective and stress-related neuropsychiatric disorders.
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Endocannabinoides , Glicéridos , Ansiedad/tratamiento farmacológico , Ácidos Araquidónicos , Inhibidores Enzimáticos/farmacología , Monoacilglicerol LipasasRESUMEN
High rates of relapse are a chronic and debilitating obstacle to effective treatment of alcohol use disorder (AUD); however, no effective treatments are available to treat symptoms induced by protracted abstinence. In the first part of this 2-part review series, we examine the literature supporting the effects of alcohol exposure within the extended amygdala (EA) neural circuitry. In Part 2, we focus on a potential way to combat negative affect associated with AUD, by exploring the therapeutic potential of the endogenous cannabinoid (eCB) system. The eCB system is a potent modulator of neural activity in the brain, and its ability to mitigate stress and negative affect has long been an area of interest for developing novel therapeutics. This review details the recent advances in our understanding of eCB signaling in 2 key regions of the EA, the central nucleus of the amygdala and the bed nucleus of the stria terminalis (BNST), and their role in regulating negative affect. Despite an established role for EA eCB signaling in reducing negative affect, few studies have examined the potential for eCB-based therapies to treat AUD-associated negative affect. In this review, we present an overview of studies focusing on eCB signaling in EA and cannabinoid modulation on EA synaptic activity. We further discuss studies suggesting dysregulation of eCB signaling in models of AUD and propose that pharmacological augmentation of eCB could be a novel approach to treat aspects of AUD. Lastly, future directions are proposed to advance our understanding of the relationship between AUD-associated negative affect and the EA eCB system that could yield new pharmacotherapies targeting negative affective symptoms associated with AUD.
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Alcoholismo/fisiopatología , Alcoholismo/terapia , Núcleo Amigdalino Central/fisiopatología , Endocannabinoides , Núcleos Septales/fisiopatología , Transducción de Señal , Animales , Depresión/inducido químicamente , Depresión/fisiopatología , Depresión/psicología , Humanos , Receptores de Cannabinoides/efectos de los fármacosRESUMEN
Leptin signals to regulate food intake and energy expenditure under conditions of normative energy homeostasis. The central expression and function of leptin receptor B (LepRb) have been extensively studied during the past two decades; however, the mechanisms by which LepRb signaling dysregulation contributes to the pathophysiology of obesity remains unclear. The paraventricular nucleus of the hypothalamus (PVN) plays a crucial role in regulating energy balance as well as the neuroendocrine axes. The role of LepRb expression in the PVN in regard to the regulation of physiological function of leptin has been controversial. The single-minded homolog 1 gene (Sim1) is densely expressed in the PVN and in parts of the amygdala, making Sim1-Cre mice a useful model for examining molecular mechanisms regulating PVN function. In this study, we characterized the physiological role of LepRb in Sim1-expressing neurons using LepRb-floxed × Sim1-Cre mice. Sim1-specific LepRb-deficient mice were surprisingly hypophagic on regular chow but gained more weight upon exposure to a high-fat diet than did their control littermates. We show that Sim1-specific deletion of a single LepRb gene copy caused decreased surface and core body temperatures as well as decreased energy expenditure in ambient room temperatures in both female and male mice. Furthermore, cold-induced adaptive (nonshivering) thermogenesis is disrupted in homozygous knockout mice. A defective thermoregulatory response was associated with defective cold-induced upregulation of uncoupling protein 1 in brown adipose tissue and reduced serum T4. Our study provides novel functional evidence supporting LepRb signaling in Sim1 neurons in the regulation of body weight, core body temperature, and cold-induced adaptive thermogenesis.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Temperatura Corporal/fisiología , Peso Corporal/fisiología , Hipotálamo/metabolismo , Neuronas/metabolismo , Receptores de Leptina/metabolismo , Proteínas Represoras/metabolismo , Transducción de Señal/fisiología , Termogénesis/fisiología , Tejido Adiposo Pardo/metabolismo , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Calorimetría Indirecta , Metabolismo Energético/fisiología , Leptina/metabolismo , Ratones , Ratones Noqueados , Ratones Transgénicos , Actividad Motora/fisiología , Receptores de Leptina/genética , Proteínas Represoras/genética , Proteína Desacopladora 1/metabolismoRESUMEN
OBJECTIVE: Essential hypertension (EH) is the most common chronic disease in the United States and a major cause of morbidity and mortality. Lifestyle interventions (e.g., diet, exercise, stress management) to reduce blood pressure (BP) are often complex with varying effectiveness. Breathing awareness meditation (BAM) is a stress management strategy with encouraging effects on BP, though widespread dissemination is hampered by the lack of an easy-to-use methodology to train and monitor BAM practices. A smartphone application (Tension Tamer [TT]) that implements BAM and tracks adherence has shown promise in addressing these gaps. This 6-month dose-response feasibility trial evaluated effects of the app on BP to further optimize BAM user guidelines. METHODS: Sixty-four adults with prehypertension were randomized to complete TT-guided BAM sessions for 5-, 10-, or 15-min intervals twice daily over 6 months. Continuous heart rate readings derived from the phone's video camera via reflective photoplethysmography were used as feedback and as an index of time-stamped adherence. Outcomes (resting BP, HR) were collected at baseline, 1-, 3-, and 6-months. RESULTS: Mixed modeling results showed a significant time effect for systolic BP (SBP) with a dose-response effect at Months 3 and 6. Adherence declined over time and was lowest in the 15-min dose condition, though SBP reductions were maintained. Generally, adherence was negatively associated with dose as the study progressed. CONCLUSIONS: Smartphone-implemented BAM appears to reduce SBP and can be a low-cost method to reach large populations. (PsycINFO Database Record
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Monitoreo Ambulatorio de la Presión Arterial/métodos , Presión Sanguínea/fisiología , Meditación/métodos , Prehipertensión/fisiopatología , Teléfono Inteligente/estadística & datos numéricos , Adulto , Estudios de Factibilidad , Femenino , Humanos , MasculinoRESUMEN
Exposure to stress is an undeniable, but in most cases surmountable, part of life. However, in certain individuals, exposure to severe or cumulative stressors can lead to an array of pathological conditions including posttraumatic stress disorder (PTSD), characterized by debilitating trauma-related intrusive thoughts, avoidance behaviors, hyperarousal, as well as depressed mood and anxiety. In the context of the rapidly changing political and legal landscape surrounding use of cannabis products in the USA, there has been a surge of public and research interest in the role of cannabinoids in the regulation of stress-related biological processes and in their potential therapeutic application for stress-related psychopathology. Here we review the current state of knowledge regarding the effects of cannabis and cannabinoids in PTSD and the preclinical and clinical literature on the effects of cannabinoids and endogenous cannabinoid signaling systems in the regulation of biological processes related to the pathogenesis of PTSD. Potential therapeutic implications of the reviewed literature are also discussed. Finally, we propose that a state of endocannabinoid deficiency could represent a stress susceptibility endophenotype predisposing to the development of trauma-related psychopathology and provide biologically plausible support for the self-medication hypotheses used to explain high rates of cannabis use in patients with trauma-related disorders.
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Moduladores de Receptores de Cannabinoides/uso terapéutico , Cannabinoides/uso terapéutico , Endocannabinoides/metabolismo , Psicotrópicos/uso terapéutico , Trastornos por Estrés Postraumático/tratamiento farmacológico , Trastornos por Estrés Postraumático/metabolismo , Animales , Moduladores de Receptores de Cannabinoides/farmacología , Cannabinoides/farmacología , Endocannabinoides/genética , Humanos , Marihuana Medicinal/farmacología , Marihuana Medicinal/uso terapéutico , Psicotrópicos/farmacología , Trastornos por Estrés Postraumático/genéticaRESUMEN
BACKGROUND: Chronic stress is an independent risk factor for essential hypertension (EH), cardiovascular disease (CVD), and is sometimes confronted by mal-adaptive coping behaviors (e.g., stress eating, excessive alcohol consumption, etc.). Pre-essential hypertension (preEH) is the leading predictor of future EH status. Breathing awareness meditation (BAM) can result in clinically beneficial blood pressure (BP) reductions, though face-to-face sessions presents barriers to reach those in need. The purpose of this study was to identify if a culturally tailored approach is needed in the design and preferences between groups of preEH African American and White adults toward using a smartphone BAM app, the Tension Tamer (TT) app. METHODS: TT includes audio delivered BAM instructions, real-time heart rate, feedback graphs and motivational reinforcement text messaging. Questionnaires and two focus groups each of African American and White adults, [n=34, mean age =43.1 years, (SD 13.8 years), 44.1% African American] were conducted to understand stress, EH knowledge, app usage along with feedback from a hands-on demonstration of TT. Grounded theory using NVivo 10 was used to develop themes and combined with the questionnaires in the analysis. RESULTS: No racial differences were found in the analysis including app use scenarios, preferences, knowledge, technology use or the attitudes and acceptance toward mobile health (mHealth) programs. Reported stress was high for African Americans [PSS-4: mean 6.87 (SD 3.3) versus mean 4.56 (SD 2.6); P=0.03]. Four main themes were found: (I) stress was pervasive; (II) coping strategies were both positive and negative; (III) BAM training was easy to incorporated; and (IV) tracking stress responses was useful. Responses suggest that additional personalization of app interfaces may drive ownership and adherence to protocols. Measures and reports of heart rate monitoring while in session were favorably viewed with low issues with confidentiality or trust issues on collected session data. CONCLUSIONS: Results suggest that a culturally tailored approach may be unnecessary in the design of BAM apps. Further investigation is warranted for other racial groups, age ranges, and disease conditions.
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We evaluated the cost-effectiveness of capsaicin 8% patch (QUTENZA™) versus pregabalin in patients with PNP from the perspective of the National Health Service (NHS) and Personal and Social Services in Scotland, UK. A decision-tree cost-effectiveness model was developed for non-diabetic patients with peripheral neuropathic pain (PNP) who were pregabalin-naïve and had not achieved adequate pain relief or tolerated conventional first- or second-line treatments. Patients entering the model received either a single application of capsaicin 8% patch or titrated daily dosing with pregabalin; after 8 weeks patients were classified as responders, non-responders, or were assumed to discontinue treatment due to intolerable adverse events. Responders continued to receive baseline treatment at intervals observed in clinical practice. Non-responders and those who discontinued treatment were assumed to receive last-line therapy (duloxetine). The base-case time horizon was 2 years. Model inputs for effectiveness, discontinuations and health-state utilities were taken from a head-to-head non-inferiority study (ELEVATE, NCT01713426). Other inputs were obtained from published sources or clinical expert opinion. Costs were expressed in GBP 2013/14. Results were presented as incremental cost-effectiveness ratios (ICER), i.e. cost per quality-adjusted life-year (QALY) gained. Model assumptions were tested with scenario analyses. Parameter uncertainty was tested using one-way and probabilistic sensitivity analyses. Compared with dose-optimized pregabalin, capsaicin 8% patch was the dominant treatment strategy (total cost difference, -£11; total QALY gain, 0.049). Capsaicin 8% patch was also the dominant treatment strategy versus pregabalin in 6 out of 7 scenario analyses. The model was most sensitive to variation in time to capsaicin 8% patch retreatment (maximum ICER, £7,951/QALY at lower-bound 95% confidence interval). At a willingness-to-pay threshold of £20,000/QALY, the probability of capsaicin 8% patch being cost-effective versus pregabalin was 97%. Capsaicin 8% patch is a cost-effective treatment option compared with dose-optimized pregabalin in patients with PNP who have failed one or more previous systemic treatments.
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Analgésicos/administración & dosificación , Capsaicina/administración & dosificación , Análisis Costo-Beneficio , Enfermedades del Sistema Nervioso Periférico/tratamiento farmacológico , Pregabalina/administración & dosificación , Fármacos del Sistema Sensorial/administración & dosificación , Administración Tópica , Analgésicos/economía , Capsaicina/economía , Humanos , Pregabalina/economía , Escocia , Fármacos del Sistema Sensorial/economíaRESUMEN
The current study characterizes the mechanism by which the Amaranthus spinosus (Amaranthaceae) decreases mast cell-mediated anaphylactic reactions. Anaphylaxis is a typical hypersensitivity Type I reaction, sharing common mechanisms with asthma in its early and late phases. Mast cells are key as effector cells in hypersensitivity Type I reactions. A. spinosus has been traditionally used in the treatment of allergic bronchitis and asthma, but its role in mast cell-mediated anaphylactic reactions has not fully been investigated. This report investigated the potential effects of the ethyl acetate fraction of A. spinosus leaves (EAFAS) against a compound 48/80 (potent secretagogue)-induced systemic anaphylactic shock paradigm in a mouse model. In addition, rat peritoneal mast cells (RPMC) were used in in vitro studies to investigate the effect of EAFAS on compound 48/80-induced peritoneal mast cell degranulation and histamine release. When administration by the oral route-1 h before compound 48/80 injection-EAFAS (at dose from 0.001-1 g/kg) completely inhibited the induced anaphylactic shock. EAFAS at concentrations ranging 0.25-1 mg/ml dose-dependently attenuated rates of mast cell degranulation and histamine release from RPMC that were evoked by compound 48/80. The results of the present investigation indicated that EAFAS stabilizes the mast cell lipid bilayer membrane, thereby preventing the perturbation of membrane and the release of histamine. As a result of these anti-degranulating and anti-histaminic effects, it can be suggested that EAFAS may have a potential use in the prophylaxis and management of anaphylactic reactions.
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Amaranthus , Anafilaxia/prevención & control , Antialérgicos/farmacología , Degranulación de la Célula/efectos de los fármacos , Liberación de Histamina/efectos de los fármacos , Mastocitos/efectos de los fármacos , Extractos Vegetales/farmacología , Acetatos/química , Amaranthus/química , Anafilaxia/inducido químicamente , Anafilaxia/inmunología , Animales , Antialérgicos/aislamiento & purificación , Membrana Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Masculino , Mastocitos/inmunología , Ratones , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta , Ratas , Ratas Wistar , Solventes/química , Factores de Tiempo , p-Metoxi-N-metilfenetilaminaRESUMEN
Endocannabinoid signaling is distributed throughout the brain, regulating synaptic release of both excitatory and inhibitory neurotransmitters. The presence of endocannabinoid signaling within stress-sensitive nuclei of the hypothalamus, as well as upstream limbic structures such as the amygdala, suggests it may play an important role in regulating the neuroendocrine and behavioral effects of stress. The evidence reviewed here demonstrates that endocannabinoid signaling is involved in both activating and terminating the hypothalamic-pituitary-adrenal axis response to both acute and repeated stress. In addition to neuroendocrine function, however, endocannabinoid signaling is also recruited by stress and glucocorticoid hormones to modulate cognitive and emotional processes such as memory consolidation and extinction. Collectively, these data demonstrate the importance of endocannabinoid signaling at multiple levels as both a regulator and an effector of the stress response.
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Moduladores de Receptores de Cannabinoides/metabolismo , Endocannabinoides , Hipotálamo/fisiopatología , Estrés Psicológico/fisiopatología , Sinapsis/metabolismo , Transmisión Sináptica/fisiología , Animales , Glucocorticoides/metabolismo , Humanos , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipotálamo-Hipofisario/fisiopatología , Hipotálamo/metabolismo , Sistema Hipófiso-Suprarrenal/metabolismo , Sistema Hipófiso-Suprarrenal/fisiopatología , Estrés Psicológico/metabolismoRESUMEN
The endocannabinoid system is a neuromodulatory system which is known to regulate emotional, cognitive, neurovegetative and motivational processes. Substantial evidence has accumulated implicating a deficit in endocannabinoid in the etiology of depression; accordingly, pharmacological augmentation of endocannabinoid signaling could be a novel target for the pharmacotherapy of depression. Within preclinical models, facilitation of endocannabinoid neurotransmission evokes both antidepressant and anxiolytic effects. Similar to the actions of conventional antidepressants, enhancement of endocannabinoid signaling can enhance serotonergic and noradrenergic transmission; increase cellular plasticity and neurotrophin expression within the hippocampus; and dampen activity within the neuroendocrine stress axis. Furthermore, limbic endocannabinoid activity is increased by both pharmacological and somatic treatments for depression, and, in turn, appears to contribute to some of the neuroadaptive alterations elicited by these treatments. These preclinical findings support the rationale for the clinical development of agents which inhibit the cellular uptake and/or metabolism of endocannabinoids in the treatment of mood disorders.
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Antidepresivos/farmacología , Depresión/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Animales , Moduladores de Receptores de Cannabinoides/metabolismo , Ensayos Clínicos como Asunto , Depresión/fisiopatología , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Endocannabinoides , Humanos , Trastornos del Humor/tratamiento farmacológico , Trastornos del Humor/fisiopatología , Transducción de Señal/efectos de los fármacosRESUMEN
Extracts of Cannabis sativa have been used for their calming and sedative effects for centuries. Recent developments in drug discovery have suggested that modulation of neuronal endogenous cannabinoid signaling systems could represent a novel approach to the treatment of anxiety-related disorders while minimizing the adverse effects of direct acting cannabinoid receptor agonists. In this study, we evaluated the effects of direct cannabinoid receptor agonists and antagonists and endocannabinoid-modulating drugs on anxiety-like behavior in mice using the elevated-plus maze. We found that the direct CB1 receptor agonists (1R,3R,4R)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3-hydroxypropyl)cyclohexan-1-ol (CP 55,940) (0.001-0.3 mg/kg) and 2,3-dihydro-5-methyl-3[(4-morpholinyl)methyl]pyrrolo [1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl)methanone mesylate) (WIN 55212-2) (0.3-10 mg/kg) increased time spent on the open arms (To) at low doses only. At the highest doses tested, both compounds altered overall locomotor activity. In contrast, Delta9-tetrahydrocannabinol (0.25-10 mg/kg) produced a dose-dependent reduction in To. The endocannabinoid uptake/catabolism inhibitor 4-hydroxyphenylarachidonylamide (AM404) (0.3-10 mg/kg) produced an increase in To at low doses and had no effect at the highest dose tested. The fatty acid amide hydrolase inhibitor cyclohexyl carbamic acid 3'-carbamoyl-biphenyl-3-yl ester (URB597) (0.03-0.3 mg/kg) produced a monophasic, dose-dependent increase in To. The CB1 receptor antagonists N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide HCl (SR141716) (1-10 mg/kg) and N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251) (1-10 mg/kg) produced dose-related decreases in To. These data indicate that activation of CB1 cannabinoid receptors reduces anxiety-like behaviors in mice and further support an anxiolytic role for endogenous cannabinoid signaling. These results suggest that pharmacological modulation of this system could represent a new approach to the treatment of anxiety-related psychiatric disorders.