Tag Archives: endocannabinoid system

Cannabinoids and glucocorticoids modulate emotional memory after stress.

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“Bidirectional and functional relationships between glucocorticoids and the endocannabinoid system have been demonstrated. Here, I review the interaction between the endocannabinoid and glucocorticoid/stress systems. Specifically, stress is known to produce rapid changes in endocannabinoid signaling in stress-responsive brain regions. In turn, the endocannabinoid system plays an important role in the downregulation and habituation of hypothalamic-pituitary-adrenocortical (HPA) axis activity in response to stress. Glucocorticoids also recruit the endocannabinoid system to exert rapid negative feedback control of the HPA axis during stress. It became increasingly clear, however, that cannabinoid CB1 receptors are also abundantly expressed in the basolateral amygdala (BLA) and other limbic regions where they modulate emotional arousal effects on memory.

 Enhancing cannabinoids signaling using exogenous CB1 receptor agonists prevent the effects of acute stress on emotional memory.

 I propose a model suggesting that the ameliorating effects of exogenously administered cannabinoids on emotional learning after acute stress are mediated by the decrease in the activity of the HPA axis via GABAergic mechanisms in the amygdala.”

http://www.ncbi.nlm.nih.gov/pubmed/23954749

Cannabinoid Receptor CB2 Modulates Axon Guidance.

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“Navigation of retinal projections towards their targets is regulated by guidance molecules and growth cone transduction mechanisms. Here, we present in vitro and in vivo evidences that the cannabinoid receptor 2 (CB2R) is expressed along the retino-thalamic pathway and exerts a modulatory action on axon guidance….

Overall, this study demonstrates that the contribution of endocannabinoids to brain development is not solely mediated by CB1R, but also involves CB2R.”

http://www.ncbi.nlm.nih.gov/pubmed/23951024

The endocannabinoid system as a possible target to treat both the cognitive and emotional features of post-traumatic stress disorder (PTSD).

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“Post-traumatic stress disorder (PTSD) is a psychiatric disorder of significant prevalence and morbidity, whose pathogenesis relies on paradoxical changes of emotional memory processing. An ideal treatment would be a drug able to block the pathological over-consolidation and continuous retrieval of the traumatic event, while enhancing its extinction and reducing the anxiety symptoms. While the latter benefit from antidepressant medications, no drug is available to control the cognitive symptomatology. Endocannabinoids regulate affective states and participate in memory consolidation, retrieval, and extinction. Clinical findings showing a relationship between Cannabis use and PTSD, as well as changes in endocannabinoid activity in PTSD patients, further suggest the existence of a link between endocannabinoids and maladaptive brain changes after trauma exposure. Along these lines, we suggest that endocannabinoid degradation inhibitors may be an ideal therapeutic approach to simultaneously treat the emotional and cognitive features of PTSD, avoiding the unwanted psychotropic effects of compounds directly binding cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/23950739

Effects of endocannabinoid and endovanilloid systems on aversive memory extinction.

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“In contextual fear conditioning animals have to integrate various elemental stimuli into a coherent representation of the condition and then associate context representation with punishment. Although several studies indicated the modulating role of endocannabinoid system (ECS) on the associative learning, ECS effect on contextual fear conditioning requires further investigations. The present study assessed the effects of the increased endocannabinoid anandamide (AEA) tone on acquisition, retrieval and extinction of the contextual fear conditioning…

 The present study indicates that ECS controls the extinction of aversive memories in the contextual fear conditioning.”

http://www.ncbi.nlm.nih.gov/pubmed/23948212

Activation of spinal cannabinoid cb2 receptors inhibits neuropathic pain in streptozotocin-induced diabetic mice.

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“The role of spinal cannabinoid systems in neuropathic pain of streptozotocin-induced diabetic mice was studied…

 … A low dose of WIN-55,212-2  significantly recovered the tail-flick latency in streptozotocin-induced diabetic mice… The selective cannabinoid CB2 receptor agonist L-759,656 also dose-dependently recovered the tail-flick latency in streptozotocin-induced diabetic mice…

 These results indicate that spinal cannabinoid systems are changed in diabetic mice and suggest that cannabinoid CB2 receptor agonists might have an ability to recover diabetic neuropathic pain.”

http://www.ncbi.nlm.nih.gov/pubmed/23892011

Controlling 2-arachidonoylglycerol metabolism as an anti-inflammatory strategy.

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“The endocannabinoid system is implicated in, and regulates, several physiological processes, ranging from food intake and energy balance to pain and inflammation.

 2-Arachidonoylglycerol (2-AG) is a full agonist at the cannabinoid receptors which classically mediate its effects. The activity of this bioactive lipid is dependent on its endogenous levels, which are tightly controlled by several hydrolases, monoacylglycerol lipase and α/β-hydrolase domain 6 and 12.

 Moreover, 2-AG is also a substrate of cyclooxygenase-2, and this reaction leads to the formation of prostaglandin glycerol esters, the effects of which remain to be fully elucidated.

 In this review we discuss the multiple mechanisms by which 2-AG controls inflammation and the therapeutic potential of 2-AG metabolism inhibitors.”

http://www.ncbi.nlm.nih.gov/pubmed/23891880

The endocannabinoid system in advanced liver cirrhosis: pathophysiological implication and future perspectives.

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“Endogenous cannabinoids (EC) are ubiquitous lipid signalling molecules providing different central and peripheral effects that are mediated mostly by the specific receptors CB1 and CB2. The EC system is highly upregulated during chronic liver disease and consistent experimental and clinical findings indicate that it plays a role in the pathogenesis of liver fibrosis and fatty liver disease associated with obesity, alcohol abuse and hepatitis C.

Furthermore, a considerable number of studies have shown that EC and their receptors contribute to the pathogenesis of the cardio-circulatory disturbances occurring in advanced cirrhosis, such as portal hypertension, hyperdynamic circulatory syndrome and cirrhotic cardiomyopathy.

More recently, the EC system has been implicated in the development of ascites, hepatic encephalopathy and the inflammatory response related to bacterial infection. Rimonabant, a selective CB1 antagonist, was the first drug acting on the EC system approved for the treatment of obesity. Unfortunately, it has been withdrawn from the market because of its neuropsychiatric side effects.

Compounds able to target selectively the peripheral CB1 receptors are under evaluation.

In addition, molecules stimulating CB2 receptor or modulating the activity of enzymes implicated in EC metabolism are promising areas of pharmacological research.

Liver cirrhosis and the related complications represent an important target for the clinical application of these compounds.”

http://www.ncbi.nlm.nih.gov/pubmed/23890208

A Link Between Autism and Cannabinoids

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“Two autism-related mutations in a synapse-adhesion protein lead to deficits in prolonged endocannabinoid signaling in mice. It’s a surprising connection that suggests such signaling problems could be implicated in autism spectrum disorders, according to a paper published today (April 11) in Neuron.

Tonic endocannabinoid signaling is long-lasting and contrasts with the brief pulses characteristic of phasic signaling. Endocannabinoid signaling in general affects memory formation, learning, pain, and other important processes, but the distinctions between tonic and phasic signaling have been poorly understood.

“It’s a very stimulating finding which could be a real turning point in understanding tonic endocannabinoids and how this otherwise mysterious lipid signaling really works,” said Bradley Alger, a neuroscientist at the University of Maryland School of Medicine…

Alger added that, if the endocannabinoid system does turn out to be connected to autism in humans, medical marijuana could turn out to hold possibility for treating autism.”

More: http://www.the-scientist.com/?articles.view/articleNo/35088/title/A-Link-Between-Autism-and-Cannabinoids/

Effects of anandamide in migraine: data from an animal model

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“Endocannabinoid system seems to be involved in the modulation of NTG-induced hyperalgesia, and probably, in the pathophysiological mechanisms of migraine…

The study confirms that a dysfunction of the endocannabinoid system may contribute to the development of migraine attacks and that a pharmacological modulation of CB receptors can be useful for the treatment of migraine pain…

By combining our data with the findings available from the literature, we can hypothesize that a dysfunction of the endocannabinoid system may contribute to the development of migraine attacks and that a specific pharmacological modulation of CB1 and CB2 receptors may be useful for the treatment of migraine pain, without deleterious effects, as well as of specific associated symptoms (nausea, in primis).”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3072518/

Cannabis Use, Effect And Potential Therapy For Alzheimer’s, MS and Parkinson’s

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“The illegal status and wide-spread use of cannabis made basic and clinical cannabis research difficult in the past decades; on the other hand, it has stimulated efforts to identify the psychoactive constituents of cannabis. As a consequence, the endocannabinoid system was discovered, which was shown to be involved in most physiological systems — the nervous, the cardiovascular, the reproductive, the immune system, to mention a few.

One of the main roles of endocannabinoids is neuroprotection, but over the last decade they have been found to affect a long list of processes, from anxiety, depression, cancer development, vasodilatation to bone formation and even pregnancy.

Cannabinoids and endocannabinoids are supposed to represent a medicinal treasure trove which waits to be discovered…

The endocannabinoid system acts as a guardian against various attacks on the mammalian body.

Conclusion

The above described research concerning the endocannabinoid-system is of importance in both basic science and in therapeutics:

  • The discovery of the cannabis plant active constituent has helped advance our understanding of cannabis use and its effects.
  • The discovery of the endocannabinoids has been of central importance in establishing the existence of a new biochemical system and its physiological roles — in particular in neuroprotection.
  • These discoveries have opened the door for the development of novel types of drugs, such as THC for the treatment of nausea and for enhancing appetite in cachectic patients.
  • The endocannabinoid system is involved in the protective reaction of the mammalian body to a long list of neurological diseases such as multiple sclerosis, Alzheimer’s and Parkinson’s disease which raises hope for novel therapeutic opportunities for these diseases.”

More: http://www.sciencedaily.com/releases/2007/10/071014163644.htm