“The endocannabinoid signaling plays a critical role in mediating rewarding effects to morphine. The relative stability for the expression and reinstatement of morphine conditioned place preference (CPP) suggests the involvement of differential neuroadaptations in learned associations between environmental cues and morphine. Changes in gene expression in hippocampus through the endogenous cannabinoid system (eCB) may accompany and mediate the development of such neuroadaptations to repeated morphine stimulation. To test this possibility, we systematically compared the expression of eCB-related genes in the dorsal hippocampus following the expression, extinction, and reinstatement of morphine CPP using quantitative RT-PCR analyses. These results suggest that differential regulation of the synthesis and/or degradation of the eCB system contribute to the expression and reinstatement of morphine CPP.” https://www.ncbi.nlm.nih.gov/pubmed/28192193]]>
Tag Archives: endocannabinoids
Endocannabinoid-dependent protection against kainic acid-induced long-term alteration of brain oscillations in guinea pigs.
“Changes in rhythmic activity can serve as early biomarkers of pathological alterations, but it remains unclear how different types of rhythmic activity are altered during neurodegenerative processes. Glutamatergic neurotoxicity, evoked by kainic acid (KA), causes hyperexcitation and acute seizures that result in delayed brain damage. We employed wide frequency range (0.1-300 Hz) local field potential recordings in guinea pigs to study the oscillatory activity of the hippocampus, entorhinal cortex, medial septum, and amygdala in healthy animals for three months after KA introduction. To clarify whether the activation of endocannabinoid (eCB) system can influence toxic KA action, AM404, an eCB reuptake inhibitor, and URB597, an inhibitor of fatty acid amide hydrolase, were applied. Our results demonstrate the protective potential of the eCB system during excitotoxic influences.” https://www.ncbi.nlm.nih.gov/pubmed/28192082]]>
Cannabinoids activate monoaminergic signaling to modulate key C. elegans behaviors.
“Cannabis or marijuana, a popular recreational drug, alters sensory perception and exerts a range of potential medicinal benefits. The present study demonstrates that the endogenous cannabinoid receptor agonists, 2-arachidonoylglycerol (2-AG) and anandamide (AEA) activate a canonical cannabinoid receptor in C. elegans and also modulate monoaminergic signaling at multiple levels. 2-AG or AEA inhibit nociception and feeding through a pathway requiring the cannabinoid-like receptor, NPR-19. 2-AG or AEA activate NPR-19 directly and cannabinoid-dependent inhibition can be rescued in npr-19 null animals by the expression of a human cannabinoid receptor, CB1, highlighting the orthology of the receptors. Cannabinoids also modulate nociception and locomotion through an NPR-19-independent pathway requiring an α2A-adrenergic-like octopamine receptor, OCTR-1, and a 5-HT1A-like receptor, SER-4, that involves a complex interaction among cannabinoid, octopaminergic and serotonergic signaling. 2-AG activates OCTR-1 directly. In contrast, 2-AG does not activate SER-4 directly, but appears to enhance SER-4-dependent serotonergic signaling by increasing endogenous 5-HT. This study defines a conserved cannabinoid signaling system in C. elegans, demonstrates the cannabinoid-dependent activation of monoaminergic signaling and highlights the advantages of studying cannabinoid signaling in a genetically-tractable whole animal model. SIGNIFICANCE STATEMENTCannabis sativa causes euphoria and exerts a wide range of medicinal benefits. For years, cannabinoids have been studied at the cellular level using tissue explants with conflicting results. To better understand cannabinoid signaling, we have used the C. elegans model to examine the effects of cannabinoids on behavior. The present study demonstrates that mammalian cannabinoid receptor ligands activate a conserved cannabinoid signaling system in C. elegans and also modulate monoaminergic signaling, potentially impacting an array of disorders, including anxiety and depression. This study highlights the potential role of cannabinoids in modulating monoaminergic signaling, and the advantages of studying cannabinoid signaling in a genetically-tractable, whole-animal model.” https://www.ncbi.nlm.nih.gov/pubmed/28188220]]>
Cannabinoid Receptors in Regulating the GI Tract: Experimental Evidence and Therapeutic Relevance.
“Cannabinoid receptors are fundamentally involved in all aspects of intestinal physiology, such as motility, secretion, and epithelial barrier function. They are part of a broader entity, the so-called endocannabinoid system which also includes their endocannabinoid ligands and the ligands’ synthesizing/degrading enzymes.
The system has a strong impact on the pathophysiology of the gastrointestinal tract and is believed to maintain homeostasis in the gut by controlling hypercontractility and by promoting regeneration after injury.
For instance, genetic knockout of cannabinoid receptor 1 leads to inflammation and cancer of the intestines. Derivatives of Δ9-tetrahydrocannabinol, such as nabilone and dronabinol, activate cannabinoid receptors and have been introduced into the clinic to treat chemotherapy-induced emesis and loss of appetite; however, they may cause many psychotropic side effects.
New drugs that interfere with endocannabinoid degradation to raise endocannabinoid levels circumvent this obstacle and could be used in the future to treat emesis, intestinal inflammation, and functional disorders associated with visceral hyperalgesia.”
https://www.ncbi.nlm.nih.gov/pubmed/28161834
Endocannabinoid Signaling and the Hypothalamic-Pituitary-Adrenal Axis.
“The elucidation of Δ9-tetrahydrocannabinol as the active principal of Cannabis sativa in 1963 initiated a fruitful half-century of scientific discovery, culminating in the identification of the endocannabinoid signaling system, a previously unknown neuromodulatory system. A primary function of the endocannabinoid signaling system is to maintain or recover homeostasis following psychological and physiological threats. We provide a brief introduction to the endocannabinoid signaling system and its role in synaptic plasticity. The majority of the article is devoted to a summary of current knowledge regarding the role of endocannabinoid signaling as both a regulator of endocrine responses to stress and as an effector of glucocorticoid and corticotrophin-releasing hormone signaling in the brain. We summarize data demonstrating that cannabinoid receptor 1 (CB1R) signaling can both inhibit and potentiate the activation of the hypothalamic-pituitary-adrenal axis by stress. We present a hypothesis that the inhibitory arm has high endocannabinoid tone and also serves to enhance recovery to baseline following stress, while the potentiating arm is not tonically active but can be activated by exogenous agonists. We discuss recent findings that corticotropin-releasing hormone in the amygdala enables hypothalamic-pituitary-adrenal axis activation via an increase in the catabolism of the endocannabinoid N-arachidonylethanolamine. We review data supporting the hypotheses that CB1R activation is required for many glucocorticoid effects, particularly feedback inhibition of hypothalamic-pituitary-adrenal axis activation, and that glucocorticoids mobilize the endocannabinoid 2-arachidonoylglycerol. These features of endocannabinoid signaling make it a tantalizing therapeutic target for treatment of stress-related disorders but to date, this promise is largely unrealized.” https://www.ncbi.nlm.nih.gov/pubmed/28134998]]>
Targeted metabolomics shows plasticity in the evolution of signaling lipids and uncovers old and new endocannabinoids in the plant kingdom.
“The remarkable absence of arachidonic acid (AA) in seed plants prompted us to systematically study the presence of C20 polyunsaturated fatty acids, stearic acid, oleic acid, jasmonic acid (JA), N-acylethanolamines (NAEs) and endocannabinoids (ECs) in 71 plant species representative of major phylogenetic clades. Given the difficulty of extrapolating information about lipid metabolites from genetic data we employed targeted metabolomics using LC-MS/MS and GC-MS to study these signaling lipids in plant evolution. Intriguingly, the distribution of AA among the clades showed an inverse correlation with JA which was less present in algae, bryophytes and monilophytes. Conversely, ECs co-occurred with AA in algae and in the lower plants (bryophytes and monilophytes), thus prior to the evolution of cannabinoid receptors in Animalia. We identified two novel EC-like molecules derived from the eicosatetraenoic acid juniperonic acid, an omega-3 structural isomer of AA, namely juniperoyl ethanolamide and 2-juniperoyl glycerol in gymnosperms, lycophytes and few monilophytes. Principal component analysis of the targeted metabolic profiles suggested that distinct NAEs may occur in different monophyletic taxa. This is the first report on the molecular phylogenetic distribution of apparently ancient lipids in the plant kingdom, indicating biosynthetic plasticity and potential physiological roles of EC-like lipids in plants.” https://www.ncbi.nlm.nih.gov/pubmed/28120902]]>
Endocannabinoid 2-arachidonoylglycerol protects inflammatory insults from sulfur dioxide inhalation via cannabinoid receptors in the brain.
“Sulfur dioxide (SO2) pollution in the atmospheric environment causes brain inflammatory insult and inflammatory-related microvasculature dysfunction. However, there are currently no effective medications targeting the harmful outcomes from chemical inhalation. Endocannabinoids (eCBs) are involved in neuronal protection against inflammation-induced neuronal injury. The 2-arachidonoylglycerol (2-AG), the most abundant eCBs and a full agonist for cannabinoid receptors (CB1 and CB2), is also capable of suppressing proinflammatory stimuli and improving microvasculature dysfunction. Here, we indicated that endogenous 2-AG protected against neuroinflammation in response to SO2 inhalation by inhibiting the activation of microglia and astrocytes and attenuating the overexpression of inflammatory cytokines, including tumor necrosis factor alpha (TNF-a), interleukin (IL)-1β, and inducible nitric oxide synthase (iNOS). In addition, endogenous 2-AG prevented cerebral vasculature dysfunction following SO2 inhalation by inhibiting endothelin 1 (ET-1), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) expression, elevating endothelial nitric oxide synthase (eNOS) level, and restoring the imbalance between thromboxane A2 (TXA2) and prostaglandin I2 (PGI2). In addition, the action of endogenous 2-AG on the suppression of inflammatory insult and inflammatory-related microvasculature dysfunction appeared to be mainly mediated by CB1 and CB2 receptors. Our results provided a mechanistic basis for the development of new therapeutic approaches for protecting brain injuries from SO2 inhalation.” https://www.ncbi.nlm.nih.gov/pubmed/28115138]]>
The Endocannabinoid System and Its Role in Eczematous Dermatoses.
“The skin serves as the foremost barrier between the internal body and the external world, providing crucial protection against pathogens and chemical, mechanical, and ultraviolet damages. The skin is a central player in the intricate network of immune, neurologic, and endocrine systems. The endocannabinoid system (ECS) includes an extensive network of bioactive lipid mediators and their receptors, functions to modulate appetite, pain, mood, and memory, and has recently been implicated in skin homeostasis. Disruption of ECS homeostasis is implicated in the pathogenesis of several prevalent skin conditions. In this review, we highlight the role of endocannabinoids in maintaining skin health and homeostasis and discuss evidence on the role of ECS in several eczematous dermatoses including atopic dermatitis, asteatotic eczema, irritant contact dermatitis, allergic contact dermatitis, and chronic pruritus. The compilation of evidence may spark directions for future investigations on how the ECS may be a therapeutic target for dermatologic conditions.” https://www.ncbi.nlm.nih.gov/pubmed/28098721
“Cannabis has been cultivated by man since Neolithic times. It was used, among others for fiber and rope production, recreational purposes and as an excellent therapeutic agent.
The isolation and characterization of the structure of one of the main active ingredients of cannabis – Δ9 – tetrahydrocannabinol as well the discovery of its 
“The identification and cloning of the two major