CB2 Cannabinoid Receptor Knockout in Mice Impairs Contextual Long-Term Memory and Enhances Spatial Working Memory.

Posted on January 29, 2016 by David

“Neurocognitive effects of cannabinoids have been extensively studied with a focus on CB1 cannabinoid receptors because CB1 receptors have been considered the major cannabinoid receptor in the nervous system. However, recent discoveries of CB2 cannabinoid receptors in the brain demand accurate determination of whether and how CB2 receptors are involved in the cognitive effects of cannabinoids.

CB2 cannabinoid receptors are primarily involved in immune functions, but also implicated in psychiatric disorders such as schizophrenia and depression. Here, we examined the effects of CB2 receptor knockout in mice on memory to determine the roles of CB2 receptors in modulating cognitive function.

Our results suggest that CB2 cannabinoid receptors play diverse roles in regulating memory depending on memory types and/or brain areas.”

http://www.ncbi.nlm.nih.gov/pubmed/26819779

Antidepressant-like effect of cannabidiol injection into the ventral medial prefrontal cortex – possible involvement of 5-HT1A and CB1 receptors.

Posted on January 25, 2016 by David

“Systemic administration of Cannabidiol (CBD), the main non-psychotomimetic constituent of Cannabis sativa, induces antidepressant-like effects.

The mechanism of action of CBD is thought to involve the activation of 5-HT1A receptors and the modulation of endocannabinoid levels with subsequent CB1 activation…

Administration of CBD into the vmPFC induces antidepressant-like effects possibly through indirect activation of CB1 and 5-HT1A receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/26801828

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

Role of hypothalamic cannabinoid receptors in post-stroke depression in rats.

Posted on January 19, 2016 by David

“One of the most common psychological consequences of stroke is post-stroke depression (PSD). While more than 30 percent of stroke patients eventually develop PSD, the neurobiological mechanisms underlying such a phenomenon have not been well investigated.

Given the critical involvement of hypothalamic-pituitary-adrenal axis and endocannabinoid system in response to stressful stimuli, we evaluated the hypothesis that cannabinoid receptors in the hypothalamus are critical for modulation of post-stroke depression-like behaviors in rats.

Taken together, these results suggest that decreased CB1 receptor expression is likely associated with the development of post-stroke depression, and CB2 receptor may be a potential therapeutic target for the treatment post-stroke depressive disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26778127

Cannabis use, depression and anxiety: A 3-year prospective population-based study.

Posted on January 17, 2016 by David

“Whether or not cannabis use may increase the risk for depression and/or anxiety is not clear. For one thing, it has not been possible to draw a definitive conclusion regarding the direction of causality, i.e. whether cannabis use increases the risk for depression/anxiety or vice versa. This study aimed at examining possible associations between cannabis use, depression and anxiety, using all three measures as both exposure and outcome…

CONCLUSIONS:

We found no longitudinal associations between cannabis use and incidence of depression/anxiety, or between depression/anxiety and later cannabis use onset.”

http://www.ncbi.nlm.nih.gov/pubmed/26773900

Cannabidiol induces rapid-acting antidepressant-like effects and enhances cortical 5-HT/glutamate neurotransmission: Role of 5-HT1A receptors.

Posted on December 30, 2015 by David

“Cannabidiol (CBD), the main non-psychotomimetic component of marihuana…

…we have evaluated the effects of CBD following acute and chronic administration in the olfactory bulbectomy mouse model of depression…

In conclusion, our findings indicate that CBD could represent a novel fast antidepressant drug, via enhancing both serotonergic and glutamate cortical signalling through a 5-HT1A receptor-dependent mechanism.”

http://www.ncbi.nlm.nih.gov/pubmed/26711860

Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase: New Targets for Future Antidepressants.

Posted on December 8, 2015 by David

“Cannabis and analogs of Δ9-tetrahydrocannabinol have been used for therapeutic purposes…

Endogenous cannabinoids have been discovered, and dysregulation of endocannabinoid signaling is implicated in the pathophysiology of major depressive disorder (MDD).

Recently, endocannabinoid hydrolytic enzymes such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have become new therapeutic targets in the treatment of MDD.

Several FAAH or MAGL inhibitors are reported to have no cannabimimetic side effects and, therefore, are new potential therapeutic options for patients with MDD who are resistant to first-line antidepressants (selective serotonin and serotonin-norepinephrine reuptake inhibitors).

In this review, we focus on the possible relationships between MDD and the endocannabinoid system as well as the inhibitors’ therapeutic potential.

MAGL inhibitors may reduce inflammatory responses through activation of cannabinoid receptor type 2.

In the hypothalamic-pituitary-adrenal axis, repeated FAAH inhibitor administration may be beneficial for reducing circulating glucocorticoid levels. Both FAAH and MAGL inhibitors may contribute to dopaminergic system regulation. Recently, several new inhibitors have been developed with strong potency and selectivity. FAAH inhibitor, MAGL inhibitor, or dual blocker use would be promising new treatments for MDD. Further pre-clinical studies and clinical trials using these inhibitors are warranted.”

http://www.ncbi.nlm.nih.gov/pubmed/26630956

Self-Medication of Somatic and Psychiatric Conditions Using Botanical Marijuana.

Posted on November 28, 2015 by David

“As a complement to research evaluating botanical marijuana as a medical therapy for various somatic and psychiatric conditions, there is a growing body of research assessing marijuana users’ self-reports of the symptoms and conditions for which they use marijuana without a physician’s recommendation.

As part of two larger web-based surveys and one in-situ survey at an outdoor marijuana festival, we asked regular marijuana users if they consumed the drug without a physician’s recommendation and, if so, to describe (or select from a checklist) the conditions for which they used marijuana as a medication.

Participants reported using marijuana to self-medicate a wide variety of both somatic conditions (such as pain, diabetes, and irritable bowel syndrome) and psychiatric conditions (such as depression, anxiety, and insomnia).

Because fewer than half of the American states, and only a few countries, allow physicians to recommend medicinal marijuana, these findings may be of interest to clinicians as they treat patients, to lawmakers and policymakers as they consider legislation allowing physicians to recommend botanical marijuana for somatic and psychiatric conditions, and to researchers evaluating conditions that individuals elect to self-medicate using botanical marijuana.”

http://www.ncbi.nlm.nih.gov/pubmed/26595140

Involvement of opioid system in antidepressant-like effect of the cannabinoid CB1 receptor inverse agonist AM-251 after physical stress in mice.

Posted on November 28, 2015 by David

“Cannabinoid inverse agonists possess antidepressant-like properties…

Numerous studies reported the interaction between opioid and cannabinoid pathways.

In this study, we used acute foot-shock stress in mice to investigate the involvement of opioid pathway in the antidepressant-like effect of the cannabinoid CB1 receptor inverse agonist AM-251.

In conclusion, the present study for the first time revealed the possible role of opioid signaling in the antidepressant-like properties of AM-251 in foot-shock stress model. “

http://www.ncbi.nlm.nih.gov/pubmed/26609670

Crosstalk between endocannabinoid and immune systems: a potential dysregulation in depression?

Posted on October 30, 2015 by David

“The endocannabinoid (eCB) system, an endogenous lipid signaling system, appears to be dysregulated in depression. The role of endocannabinoids (eCBs) as potent immunomodulators, together with the accumulating support for a chronic low-grade inflammatory profile in depression, suggests a compelling hypothesis for a fundamental impairment in their intercommunication, in depression.

OBJECTIVE:

We aim to review previous literature on individual associations between the immune and eCB systems and depression. It will focus on peripheral and central mechanisms of crosstalk between the eCB and immune systems. A potential dysregulation in this crosstalk will be discussed in the context of depression.

RESULTS:

Investigations largely report a hypoactivity of the eCB system and increased inflammatory markers in individuals with depression. Findings depict a multifaceted communication whereby immunocompetent and eCB-related cells can both influence the suppression and enhancement of the other’s activity in both the periphery and central nervous system. A dysregulation of the eCB system, as seen in depression, appears to be associated with central and peripheral concentrations of inflammatory agents implicated in the pathophysiology of this illness.

CONCLUSION:

The eCB and immune systems have been individually associated with and implicated in pathogenic mechanisms of depression. Both systems tightly regulate the other’s activity. As such, a dysregulation in this crosstalk has potential to influence the onset and maintenance of this neuropsychiatric illness. However, few studies have investigated both systems and depression conjointly. This review highlights the demand to consider joint eCB-immune interactions in the pathoetiology of depression.”

http://www.ncbi.nlm.nih.gov/pubmed/26483037

Endocannabinoids and Mental Disorders.

Posted on September 27, 2015 by David

“Preclinical and clinical data fully support the involvement of the endocannabinoid system in the etiopathogenesis of several mental diseases.

In this review we will briefly summarize the most common alterations in the endocannabinoid system, in terms of cannabinoid receptors and endocannabinoid levels, present in mood disorders (anxiety, posttraumatic stress disorder, depression, bipolar disorder, and suicidality) as well as psychosis (schizophrenia) and autism.

The arising picture for each pathology is not always straightforward; however, both animal and human studies seem to suggest that pharmacological modulation of this system might represent a novel approach for treatment.”

http://www.ncbi.nlm.nih.gov/pubmed/26408164