Understanding the endocannabinoid system as a modulator of the trigeminal pain response to concussion.

“Post-traumatic headache is the most common symptom of postconcussion syndrome and becomes a chronic neurological disorder in a substantial proportion of patients.

This review provides a brief overview of the epidemiology of postconcussion headache, research models used to study this disorder, as well as the proposed mechanisms.

An objective of this review is to enhance the understanding of how the endogenous cannabinoid system is essential for maintaining the balance of the CNS and regulating inflammation after injury, and in turn making the endocannabinoid system a potential modulator of the trigeminal response to concussion.

The review describes the role of endocannabinoid modulation of pain and the potential for use of phytocannabinoids to treat pain, migraine and concussion.”

https://www.ncbi.nlm.nih.gov/pubmed/30202590

Review of the neurological benefits of phytocannabinoids.

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“Numerous physical, psychological, and emotional benefits have been attributed to marijuana since its first reported use in 2,600 BC in a Chinese pharmacopoeia. The phytocannabinoids, cannabidiol (CBD), and delta-9-tetrahydrocannabinol (Δ9-THC) are the most studied extracts from cannabis sativa subspecies hemp and marijuana. CBD and Δ9-THC interact uniquely with the endocannabinoid system (ECS). Through direct and indirect actions, intrinsic endocannabinoids and plant-based phytocannabinoids modulate and influence a variety of physiological systems influenced by the ECS.

METHODS:

In 1980, Cunha et al. reported anticonvulsant benefits in 7/8 subjects with medically uncontrolled epilepsy using marijuana extracts in a phase I clinical trial. Since then neurological applications have been the major focus of renewed research using medical marijuana and phytocannabinoid extracts.

RESULTS:

Recent neurological uses include adjunctive treatment for malignant brain tumors, Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, neuropathic pain, and the childhood seizure disorders Lennox-Gastaut and Dravet syndromes. In addition, psychiatric and mood disorders, such as schizophrenia, anxiety, depression, addiction, postconcussion syndrome, and posttraumatic stress disorders are being studied using phytocannabinoids.

CONCLUSIONS:

In this review we will provide animal and human research data on the current clinical neurological uses for CBD individually and in combination with Δ9-THC. We will emphasize the neuroprotective, antiinflammatory, and immunomodulatory benefits of phytocannabinoids and their applications in various clinical syndromes.”

https://www.ncbi.nlm.nih.gov/pubmed/29770251

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5938896/

Chronic High Doses of Cannabinoids Promote Hippocampal Neurogenesis

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“Hippocampal neurogenesis is suppressed following chronic administration of the major drugs of abuse (including opiates, alcohol, nicotine, and cocaine). However, CB1-knockout mice display significantly decreased hippocampal neurogenesis, suggesting that CB1 receptors activated by endogenous, plant-derived, or synthetic cannabinoids may promote hippocampal neurogenesis.

Cannabinoids can regulate the proliferation of hippocampal NS/PCs by acting on CB1 receptors. They found that both the synthetic cannabinoid HU210 and the endocannabinoid anandamide profoundly promote embryonic hippocampal NS/PC proliferation. Chronic, but not acute, HU210 significantly increases the number of newborn hippocampal neurons in adult rats by promoting NS/PC proliferation.

A significant increase was observed in the hipoppocampal newborn neurons of mice following twice-daily HU210 injection for 10 days.

This suggests that cannabinoids are the only illicit drug that can promote adult hippocampal neurogenesis following chronic  administration.”

Cannabinoids promote embryonic and adult hippocampus neurogenesis and produce anxiolytic- and antidepressant-like effects.” https://www.jci.org/articles/view/25509

http://www.science20.com/science_why_not/blog/chronic_high_doses_cannabinoids_promote_hippocampal_neurogenesis

Role for neuronal nitric-oxide synthase in cannabinoid-induced neurogenesis.

Role for neuronal nitric-oxide synthase in cannabinoid-induced neurogenesis.“Cannabinoids, acting through the CB1 cannabinoid receptor (CB1R), protect the brain against ischemia and related forms of injury.

This may involve inhibiting the neurotoxicity of endogenous excitatory amino acids and downstream effectors, such as nitric oxide (NO).

Cannabinoids also stimulate neurogenesis in the adult brain through activation of CB1R.

Because NO has been implicated in neurogenesis, we investigated whether cannabinoid-induced neurogenesis, like cannabinoid neuroprotection, might be mediated through alterations in NO production.” https://aggregator.leafscience.org/role-for-neuronal-nitric-oxide-synthase-in-cannabinoid-induced-neurogenesis/

“Nitric oxide negatively regulates mammalian adult neurogenesis.”  http://www.pnas.org/content/100/16/9566.long

“Thus, cannabinoids appear to stimulate adult neurogenesis by opposing the antineurogenic effect of NO.” http://jpet.aspetjournals.org/content/jpet/319/1/150.full.pdf

Endocannabinoid system and cannabinoids in neurogenesis – new opportunities for neurological treatment? Reports from experimental studies.

“Neurogenesis is one of the most important phenomenona affecting human life. This process consists of proliferation, migration and differentiation of neuroblasts and synaptic integrations of newborn neurons.
Proliferation of new cells continues into old age, also in humans, although the most extensive process of cell formation occurs during the prenatal period. It is possible to distinguish two regions in the brain responsible for neurogenesis: the dentate gyrus (DG) of the hippocampus and the sub-ventricular zone (SVZ). Hippocampal neurogenesis is very sensitive to various physiological and pathological stimuli.
The functional integration of the newly-born dentate granule cells into hippocampal circuitry, and their ability to mediate long-term potentiation in DG, has led to the hypothesis that neurogenesis in the adult brain may play a key role in learning and memory function, as well as cognitive dysfunction in some diseases.
Brain disorders, such as neurodegenerative diseases or traumatic brain injuries, significantly affect migration, proliferation and differentiation of neural cells. In searching for the best neurological drugs protecting neuronal cells, stimulating neurogenesis, while also developing no side-effects, endocannabinoids proved to be a strong group of substances having many beneficial properties.
Therefore, the latest data is reviewed of the various experimental studies concerning the analysis of the most commonly studied cannabinoids and their impact on neurogenesis.”

WWL70 protects against chronic constriction injury-induced neuropathic pain in mice by cannabinoid receptor-independent mechanisms.

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“Targeting the endocannabinoid system has emerged as an effective strategy for the treatment of inflammatory and neurological diseases.

Unlike the inhibition of the principal 2-arachidonyl glycerol (2-AG) hydrolytic enzyme monoacylglycerol lipase (MAGL), which leads to 2-AG overload and cannabinoid receptor desensitization, selective inhibition of the minor 2-AG hydrolytic enzyme alpha, beta-hydrolase domain 6 (ABHD6) can provide therapeutic benefits without producing cannabimimetic side effects. We have shown that inhibition of ABHD6 significantly reduces neuroinflammation and exerts neuroprotection in animal models of traumatic brain injury and multiple sclerosis. However, the role of ABHD6 inhibition on neuropathic pain has not been explored.

CONCLUSIONS:

This study reveals a novel mechanism for the antinociceptive effect of the 2-AG catabolic enzyme ABHD6 inhibitor WWL70. Understanding the interaction between endocannabinoid and eicosanoid pathways might provide a new avenue for the treatment of inflammatory and neuropathic pain.”

Role of the endogenous cannabinoid receptor 1 in brain injury induced by chronic intermittent hypoxia in rats.

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“This study investigated the effect of rimonabant, a cannabinoid receptor type 1 (CB1) antagonist, on calcium/calmodulin dependent protein kinase II (CaMKII) and CB1 in chronic intermittent hypoxia (CIH).

Rimonabant had a protective effect against CIH.” https://www.ncbi.nlm.nih.gov/pubmed/29264962

http://www.tandfonline.com/doi/abs/10.1080/00207454.2017.1420069

 

Neuroprotective Properties of Endocannabinoids N-Arachidonoyl Dopamine and N-Docosahexaenoyl Dopamine Examined in Neuronal Precursors Derived from Human Pluripotent Stem Cells.

Biochemistry (Moscow)

“Neuroprotective properties of endocannabinoids N-arachidonoyl dopamine (NADA) and N-docosahexaenoyl dopamine (DHDA) were examined in neuronal precursor cells differentiated from human induced pluripotent stem cells and subjected to oxidative stress. Both compounds exerted neuroprotective activity, which was enhanced by elevating the concentration of the endocannabinoids within the 0.1-10 µM range. However, both agents at 10 µM concentration showed a marked toxic effect resulting in death of ~30% of the cells. Finally, antagonists of cannabinoid receptors as well as the receptor of the TRPV1 endovanilloid system did not hamper the neuroprotective effects of these endocannabinoids.”

https://www.ncbi.nlm.nih.gov/pubmed/29223163

N-Arachidonoyl Dopamine: A Novel Endocannabinoid and Endovanilloid with Widespread Physiological and Pharmacological Activities.

Mary Ann Liebert, Inc. publishers

“N-arachidonoyl dopamine (NADA) is a member of the family of endocannabinoids to which several other N-acyldopamines belong as well. Their activity is mediated through various targets that include cannabinoid receptors or transient receptor potential vanilloid (TRPV)1. Synthesis and degradation of NADA are not yet fully understood. Nonetheless, there is evidence that NADA plays an important role in nociception and inflammation in the central and peripheral nervous system. The TRPV1 receptor, for which NADA is a potent agonist, was shown to be an endogenous transducer of noxious heat. Moreover, it has been demonstrated that NADA exerts protective and antioxidative properties in microglial cell cultures, cortical neurons, and organotypical hippocampal slice cultures. NADA is present in very low concentrations in the brain and is seemingly not involved in activation of the classical pathways. We believe that treatment with exogenous NADA during and after injury might be beneficial. This review summarizes the recent findings on biochemical properties of NADA and other N-acyldopamines and their role in physiological and pathological processes. These findings provide strong evidence that NADA is an effective agent to manage neuroinflammatory diseases or pain and can be useful in designing novel therapeutic strategies.”

https://www.ncbi.nlm.nih.gov/pubmed/29082315

http://online.liebertpub.com/doi/10.1089/can.2017.0015

Selective activation of cannabinoid receptor-2 reduces neuroinflammation after traumatic brain injury via alternative macrophage polarization.

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“Inflammation is an important mediator of secondary neurological injury after traumatic brain injury (TBI). Endocannabinoids, endogenously produced arachidonate based lipids, have recently emerged as powerful anti-inflammatory compounds, yet the molecular and cellular mechanisms underlying these effects are poorly defined. Endocannabinoids are physiological ligands for two known cannabinoid receptors, CB1R and CB2R. In the present study, we hypothesized that selective activation of CB2R attenuates neuroinflammation and reduces neurovascular injury after TBI. Taken together, our findings support the development of selective CB2R agonists as a therapeutic strategy to improve TBI outcomes while avoiding the psychoactive effects of CB1R activation.”   https://www.ncbi.nlm.nih.gov/pubmed/29079445   http://www.sciencedirect.com/science/article/pii/S0889159117304774

“The Cannabinoid CB2 Receptor as a Target for Inflammation-Dependent Neurodegeneration. The first approved cannabinoid drugs were analogues of Δ9-tetrahydrocannabinol (Δ9-THC). Dronabinol is a natural isomer of THC that is found in the cannabis plant” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2435344/

“Cannabinoid Receptor CB2 Is Involved in Tetrahydrocannabinol-Induced Anti-Inflammation against Lipopolysaccharide in MG-63 Cells. These results suggested that CB2 is involved in the THC-induced anti-inflammation”  https://www.hindawi.com/journals/mi/2015/362126/

“Cannabinoids as novel anti-inflammatory drugs. Manipulation of endocannabinoids and/or use of exogenous cannabinoids in vivo can constitute a potent treatment modality against inflammatory disorders.  For several centuries, marijuana has been used as an alternative medicine in many cultures and, recently, its beneficial effects have been shown”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2828614/

“Cannabinoids as neuroprotective agents in traumatic brain injury.  Cannabinoids of all classes have the ability to protect neurons from a variety of insults that are believed to underlie delayed neuronal death after traumatic brain injury (TBI), including excitotoxicity, calcium influx, free radical formation and neuroinflammation.” https://www.ncbi.nlm.nih.gov/pubmed/15281893

“Effect of marijuana use on outcomes in traumatic brain injury. A positive THC screen is associated with decreased mortality in adult patients sustaining TBI.”  https://www.ncbi.nlm.nih.gov/pubmed/25264643