Cannabinoid type-1 receptor signaling in central serotonergic neurons regulates anxiety-like behavior and sociability.

Posted on September 22, 2015 by David

“The endocannabinoid (eCB) system possesses neuromodulatory functions by influencing the release of various neurotransmitters, including γ-aminobutyric acid (GABA) and glutamate. A functional interaction between eCBs and the serotonergic system has already been suggested.

Previously, we showed that cannabinoid type-1 (CB1) receptor mRNA and protein are localized in serotonergic neurons of the raphe nuclei, implying that the eCB system can modulate serotonergic functions.

In order to substantiate the physiological role of the CB1 receptor in serotonergic neurons of the raphe nuclei, we generated serotonergic 5-hydroxytryptamine (5-HT) neuron-specific CB 1 receptor-deficient mice, using the Cre/loxP system with a tamoxifen-inducible Cre recombinase under the control of the regulatory sequences of the tryptophan hydroxylase 2 gene (TPH2-CreER (T2)), thus, restricting the recombination to 5-HT neurons of the central nervous system (CNS).

Applying several different behavioral paradigms, we revealed that mice lacking the CB1 receptor in serotonergic neurons are more anxious and less sociable than control littermates. Thus, we were able to show that functional CB1 receptor signaling in central serotonergic neurons modulates distinct behaviors in mice.”

http://www.ncbi.nlm.nih.gov/pubmed/26388750

In vitro and non-invasive in vivo effects of the cannabinoid-1 receptor agonist AM841 on gastrointestinal motor function in the rat.

Posted on September 22, 2015 by David

“Cannabinoids have been traditionally used for the treatment of gastrointestinal (GI) symptoms, but the associated central effects, through cannabinoid-1 receptors (CB1R), constitute an important drawback. Our aims were to characterize the effects of the recently developed highly potent long-acting megagonist AM841 on GI motor function and to determine its central effects in rats…

The CB1R megagonist AM841 may potently depress GI motor function in the absence of central effects. This effect may be mediated peripherally and may be useful in the treatment of GI motility disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26387676

Cannabis for the Management of Pain: Assessment of Safety Study (COMPASS).

Posted on September 20, 2015 by David

“Cannabis is widely used as a self-management strategy by patients with a wide range of symptoms and diseases including chronic noncancer pain.

The safety of cannabis use for medical purposes has not been systematically evaluated. We conducted a prospective cohort study to describe safety issues among subjects with chronic noncancer pain.

A standardized herbal cannabis product (12.5% THC) was dispensed to eligible subjects for a one-year period; controls were subjects with chronic pain from the same clinics who were not cannabis users.

The primary outcome consisted of serious adverse events (SAEs) and non-serious adverse events (AEs). Secondary safety outcomes included pulmonary and neurocognitive function and standard hematology, biochemistry, renal, liver and endocrine function.

Secondary efficacy parameters included pain and other symptoms, mood, and quality of life.

Two hundred and sixteen individuals with chronic pain were recruited to the cannabis group (141 current users and 58 ex-users) and 215 controls (chronic pain but no current cannabis use) from seven clinics across Canada. The median daily cannabis dose was 2.5g/d.

There was no difference in risk of SAEs between groups.

Medical cannabis users were at increased risk of non-serious AEs; most were mild to moderate. There were no differences in secondary safety assessments.

Quality-controlled herbal cannabis, when used by cannabis-experienced patients as part of a monitored treatment program over one year, appears to have a reasonable safety profile.

This study evaluated the safety of cannabis use by patients with chronic pain over one year. The study found that there was a higher rate of adverse events among cannabis users compared to controls but not for serious adverse events at an average dose of 2.5g herbal cannabis per day.”

http://www.ncbi.nlm.nih.gov/pubmed/26385201

http://www.thctotalhealthcare.com/category/pain-2/

Effect of combined doses of Δ9-tetrahydrocannabinol (THC) and cannabidiolic acid (CBDA) on acute and anticipatory nausea using rat (Sprague- Dawley) models of conditioned gaping.

Posted on September 19, 2015 by David

“Δ9-Tetrahydrocannabinol (THC) and cannabidiolic acid (CBDA) found in cannabis both reduce the distressing symptom of nausea…

Combined subthreshold doses of THC and CBDA reduced acute nausea.

Higher doses of THC or CBDA alone, as well as these combined doses also reduced acute nausea.

Combined subthreshold doses of THC:CBDA are particularly effective as a treatment for acute nausea. At higher doses, CBDA may attenuate THC-induced interference with learning.”

http://www.ncbi.nlm.nih.gov/pubmed/26381155

A Cannabinoid Receptor 2 Agonist Prevents Thrombin-Induced Blood-Brain Barrier Damage via the Inhibition of Microglial Activation and Matrix Metalloproteinase Expression in Rats.

Posted on September 18, 2015 by David

“Thrombin mediates the life-threatening cerebral edema and blood-brain barrier (BBB) damage that occurs after intracerebral hemorrhage (ICH).

We previously found that the selective cannabinoid receptor 2 (CB2R) agonist JWH-133 reduced brain edema and neurological deficits following germinal matrix hemorrhage (GMH).

We explored whether CB2R stimulation ameliorated thrombin-induced brain edema and BBB permeability as well as the possible molecular mechanism involved.

The results demonstrated that JWH-133 administration significantly decreased thrombin-induced brain edema and reduced the number of Iba-1-positive microglia…

We demonstrated that CB2R stimulation reduced thrombin-induced brain edema and alleviated BBB damage.”

http://www.ncbi.nlm.nih.gov/pubmed/26376816

Neural correlates of cannabidiol and Δ9-tetrahydrocannabinol interactions in mice: implications for medical cannabis.

Posted on September 18, 2015 by David

“It has been proposed that medicinal strains of cannabis and therapeutic preparations would be safer with a more balanced concentration ratio of Δ9-tetrahydrocannabinol (THC) to cannabidiol (CBD), as CBD reduces the adverse psychotropic effects of THC.

The aim of this study is to investigate whether CBD modulates THC-induced functional effects and c-Fos expression in a 1:1 dose ratio that approximates therapeutic strains of cannabis and nabiximols.

These data re-affirm that CBD modulates the pharmacological actions of THC and provide information regarding brain regions involved in the interaction between CBD and THC.”

http://www.ncbi.nlm.nih.gov/pubmed/26377899

[Cannabis – therapy for the future?]

Posted on September 17, 2015 by David

“Despite all the progress achieved in the treatment of chronic gastrointestinal diseases, in some patients the treatment does not reach long-term optimum effectiveness. Therefore a number of patients have turned to complementary and alternative medicine (CAM).

Of the different types of CAM patients with GIT diseases tend to prefer in particular homeopathy, acupuncture and not least phytotherapy, where therapeutic use of cannabis may also be included.

The pathophysiological basis of therapeutic effect of curative cannabis has not been fully clarified so far.

Many scientists in many fields of medicine and pharmacology have been engaged in the study of effects of cannabinoids on the body since the beginning of the 20th century with the interest significantly increasing in the 1980s.

The discovery of CB receptors (1988) and endogenous molecules which activate these receptors (1992) led to the discovery of the endocannabinoid system.

Pharmacological modulation of the endogenous cannabinoid system offers new therapeutic possibilities of treatment of many illnesses and symptoms including the GIT disorders, including of nausea, vomiting, cachexia, IBS, Crohns disease and some other disorders.

Cannabinoids are attractive due to their therapeutic potential – they affect a lot of symptoms with minimum side effects.

Experience of patients with GIT disorders show that the use of cannabis is effective and helps in cases where the standard therapy fails.”

http://www.ncbi.nlm.nih.gov/pubmed/26375695

The effects of endocannabinoid receptor agonist anandamide and antagonist rimonabant on opioid analgesia and tolerance in rats.

Posted on September 17, 2015 by David

“The role of the cannabinoid (CB) system in the tolerance to analgesic effect of opioid remains obscure. The aim of the present study was to evaluate the effects of the endocannabinoid nonselective receptor agonist anandamide (AEA) and CB1 receptor antagonist rimonabant (SR141716) on morphine analgesia and tolerance in rats.

The findings suggested that AEA in combination with morphine produced a significant increase in expression of analgesic tolerance to morphine.

Conversely, cannabinoid receptor antagonist SR141716 attenuated morphine analgesic tolerance.

In addition, administration of AEA with morphine increased morphine analgesia.

In conclusion, we observed that the cannabinoid receptor agonist anandamide and CB1 receptor antagonist SR141716 plays a significant role in the opioid analgesia and tolerance.”

http://www.ncbi.nlm.nih.gov/pubmed/26374993

New insights on the role of the endocannabinoid system in the regulation of energy balance.

Posted on September 17, 2015 by David

“Within the last 15 years, the endocannabinoid system (ECS) has emerged as a lipid signaling system critically involved in the regulation of energy balance, since it exerts a regulatory control on every aspect related to the search, the intake, the metabolism and the storage of calories.

An overactive endocannabinoid-cannabinoid type 1 (CB1) receptor signaling promotes the development of obesity, insulin resistance and dyslipidemia, representing a valuable pharmacotherapeutic target for obesity and metabolic disorders.

However, due to psychiatric side effects, the first generation of brain-penetrant CB1 receptor blockers developed as anti-obesity treatment was removed from the European market in late 2008.

Since then, recent studies have identified new mechanisms of action of the ECS in energy balance and metabolism, as well as novel ways of targeting the system that may be efficacious for the treatment of obesity and metabolic disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26374449

Abnormalities in neuroendocrine stress response in psychosis: the role of endocannabinoids.

Posted on September 17, 2015 by David

“The aim of this article is to summarize current evidence regarding alterations in the neuroendocrine stress response system and endocannabinoid system and their relationship in psychotic disorders such as schizophrenia.

Exposure to stress is linked to the development of a number of psychiatric disorders including psychosis.

However, the precise role of stress in the development of psychosis and the possible mechanisms that might underlie this are not well understood. Recently the cannabinoid hypothesis of schizophrenia has emerged as a potential line of enquiry.

Endocannabinoid levels are increased in patients with psychosis compared with healthy volunteers; furthermore, they increase in response to stress, which suggests another potential mechanism for how stress might be a causal factor in the development of psychosis.

However, research regarding the links between stress and the endocannabinoid system is in its infancy.

Evidence summarized here points to an alteration in the baseline tone and reactivity of the hypothalamic-pituitary-adrenal (HPA) axis as well as in various components of the endocannabinoid system in patients with psychosis.

Moreover, the precise nature of the inter-relationship between these two systems is unclear in man, especially their biological relevance in the context of psychosis.

Future studies need to simultaneously investigate HPA axis and endocannabinoid alterations both at baseline and following experimental perturbation in healthy individuals and those with psychosis to understand how they interact with each other in health and disease and obtain mechanistic insight as to their relevance to the pathophysiology of schizophrenia.”

http://www.ncbi.nlm.nih.gov/pubmed/26370602