Cannabidiol Counteracts Amphetamine-Induced Neuronal and Behavioral Sensitization of the Mesolimbic Dopamine Pathway through a Novel mTOR/p70S6 Kinase Signaling Pathway.

“Schizophrenia-related psychosis is associated with disturbances in mesolimbic dopamine (DA) transmission, characterized by hyperdopaminergic activity in the mesolimbic pathway. Currently, the only clinically effective treatment for schizophrenia involves the use of antipsychotic medications that block DA receptor transmission. However, these medications produce serious side effects leading to poor compliance and treatment outcomes.

Emerging evidence points to the involvement of a specific phytochemical component of marijuana called cannabidiol (CBD), which possesses promising therapeutic properties for the treatment of schizophrenia-related psychoses.

Our findings demonstrate a novel mechanism for the putative antipsychotic-like properties of CBD in the mesolimbic circuitry. We identify the molecular signaling pathways through which CBD may functionally reduce schizophrenia-like neuropsychopathology.

SIGNIFICANCE STATEMENT:

The cannabis-derived phytochemical, cannabidiol (CBD), has been shown to have pharmacotherapeutic efficacy for the treatment of schizophrenia.

However, the mechanisms by which CBD may produce antipsychotic effects are entirely unknown. Using preclinical behavioral procedures combined with molecular analyses and in vivo neuronal electrophysiology, our findings identify a functional role for the nucleus accumbens as a critical brain region whereby CBD can produce effects similar to antipsychotic medications by triggering molecular signaling pathways associated with the effects of classic antipsychotic medications.

Specifically, we report that CBD can attenuate both behavioral and dopaminergic neuronal correlates of mesolimbic dopaminergic sensitization, via a direct interaction with mTOR/p70S6 kinase signaling within the mesolimbic pathway.”

http://www.ncbi.nlm.nih.gov/pubmed/27147666

http://www.thctotalhealthcare.com/category/schizophrenia/

Neuroscientists discover previously unknown function of cannabinoid receptor

Neuroscientists discover previously unknown function of cannabinoid receptor

“Previously Unknown Function of a Cannabinoid Receptor Identified.  Study could improve our insights into brain diseases.” http://neurosciencenews.com/cb2-cannabinoid-receptor-hippocampus-4147/

“In the brain, there is a delicate interplay of signaling substances and cellular activity. Scientists have now identified another key player within this ensemble. In a laboratory study they found that the ‘cannabinoid type 2 receptor’ influences information processing inside the hippocampus. The research results might help advance our understanding of schizophrenia and Alzheimer’s, say the authors.”  https://www.sciencedaily.com/releases/2016/05/160502111228.htm

“The cannabinoid type 2 receptor – also called “CB2 receptor” – is a special membrane protein. Its function is to receive chemical signals that control cellular activity. “Until now, this receptor was considered part of the immune system without function in nerve cells. However, our study shows that it also plays an important role in the signal processing of the brain,” explains Professor Dietmar Schmitz, Speaker for the DZNE-Site Berlin and Director of the Neuroscience Research Center of the Charité (NWFZ/NeuroCure).”  https://scienceblog.com/483935/neuroscientists-discover-previously-unknown-function-cannabinoid-receptor/

 

Cannabinoid Type 2 Receptors Mediate a Cell Type-Specific Plasticity in the Hippocampus

“Endocannabinoids (eCBs) exert major control over neuronal activity by activating cannabinoid receptors (CBRs).

The functionality of the eCB system is primarily ascribed to the well-documented retrograde activation of presynaptic CB1Rs.

We find that action potential-driven eCB release leads to a long-lasting membrane potential hyperpolarization in hippocampal principal cells that is independent of CB1Rs.

The hyperpolarization, which is specific to CA3 and CA2 pyramidal cells (PCs), depends on the activation of neuronal CB2Rs, as shown by a combined pharmacogenetic and immunohistochemical approach.

Upon activation, they modulate the activity of the sodium-bicarbonate co-transporter, leading to a hyperpolarization of the neuron.

CB2R activation occurred in a purely self-regulatory manner, robustly altered the input/output function of CA3 PCs, and modulated gamma oscillations in vivo.

To conclude, we describe a cell type-specific plasticity mechanism in the hippocampus that provides evidence for the neuronal expression of CB2Rs and emphasizes their importance in basic neuronal transmission.”

http://www.cell.com/neuron/abstract/S0896-6273(16)30025-3

Cannabidiol attenuates catalepsy induced by distinct pharmacological mechanisms via 5-HT1A receptor activation in mice.

“Cannabidiol (CBD) is a non-psychotomimetic compound from Cannabis sativa plant that produces antipsychotic effects in rodents and humans.

It also reverses L-dopa-induced psychotic symptoms and improves motor function in Parkinson’s patients. This latter effect raised the possibility that CBD could have beneficial effects on motor related striatal disorders.

To investigate this possibility we evaluated if CBD would prevent catalepsy induced by drugs with distinct pharmacological mechanisms.

These findings indicate that CBD can attenuate catalepsy caused by different mechanisms (D2 blockade, NOS inhibition and CB1 agonism) via 5-HT1A receptor activation, suggesting that it could be useful in the treatment of striatal disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/23791616

Cannabidiol attenuates haloperidol-induced catalepsy and c-Fos protein expression in the dorsolateral striatum via 5-HT1A receptors in mice.

“Cannabidiol (CBD) is a major non-psychoactive compound from Cannabis sativa plant.

Given that CBD reduces psychotic symptoms without inducing extrapyramidal motor side-effects in animal models and schizophrenia patients, it has been proposed to act as an atypical antipsychotic.

In addition, CBD reduced catalepsy induced by drugs with distinct pharmacological mechanisms, including the typical antipsychotic haloperidol.

Altogether, these results suggest that CBD acts in the dorsal striatum to improve haloperidol-induced catalepsy via postsynaptic 5-HT1A receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27131780

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

Image result for Curr Clin Pharmacol.

“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.

Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.

The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.

Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.

Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.

Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.

One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.

Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.

In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27086601

Cannabis Use Linked to Better Social Skills in Psychosis

“Psychosis patients who have used cannabis have greater premorbid social skills than patients with psychosis who have never used the drug, data from five European countries suggest.

Laura Ferraro, a PhD student in psychiatry at the University of Palermo, in Italy, and colleagues found that lifetime cannabis use was associated with significantly increased improvements in premorbid social adjustment among psychosis patients.”

http://www.medscape.com/viewarticle/860664

Peripubertal treatment with cannabidiol prevents the emergence of psychosis in an animal model of schizophrenia

“Currently, the pharmacotherapy of schizophrenia is still associated with significant side effects and high rates of treatment resistance, causing a great deal of suffering to patients and their caregivers. Developing safe interventions able to prevent the emergence of full-blown psychosis would therefore represent a major advance.

Cannabidiol (CBD) is a non-psychotomimetic compound of Cannabis sativa that presents antipsychotic properties in animal models and humans.

However, despite the growing evidence of CBD’s neuroprotective effects and therapeutic application in schizophrenia, so far no study has addressed its potential as a preventive intervention.”

http://www.schres-journal.com/article/S0920-9964(16)30060-3/abstract

http://www.thctotalhealthcare.com/category/schizophrenia/

Therapeutic Potential of Cannabinoids in Psychosis.

“Over recent years, the interest in the endocannabinoid system (ECS) as a new target for the treatment of schizophrenia has evolved.

The ECS represents one of the most relevant neurotransmitter systems in the brain and mainly fulfills a homeostatic role in terms of neurotransmission but also with respect to inflammatory processes.

Two main approaches to the modulation of endocannabinoid functioning have been chosen so far. First, the selective blockade or inverse agonism of the type 1 cannabinoid receptor has been tested for the improvement of acute psychotic symptoms, as well as for the improvement of cognitive functions in schizophrenia.

Second, the modulation of endocannabinoid levels by use of the phytocannabinoid cannabidiol and selective fatty acid amide hydrolase inhibitors has been proposed, and the antipsychotic properties of cannabidiol are currently being investigated in humans.

Unfortunately, for most of these trials that have focused on psychopathological and cognitive effects of cannabidiol, no published data are available. However, there is first evidence that cannabidiol may ameliorate psychotic symptoms with a superior side-effect profile compared with established antipsychotics.

In conclusion, several clinical trials targeting the ECS in acute schizophrenia have either been completed or are underway. Although publicly available results are currently limited, preliminary data indicate that selected compounds modulating the ECS may be effective in acute schizophrenia.

Nevertheless, so far, sample sizes of patients investigated are not sufficient to come to a final judgment, and no maintenance studies are available to ensure long-term efficacy and safety.”

http://www.ncbi.nlm.nih.gov/pubmed/26852073

http://www.thctotalhealthcare.com/category/schizophrenia/

Cannabidiol, neuroprotection and neuropsychiatric disorders.

“Cannabidiol (CBD) is a non-psychotomimetic phytocannabinoid derived from Cannabis sativa.

It has possible therapeutic effects over a broad range of neuropsychiatric disorders.

CBD attenuates brain damage associated with neurodegenerative and/or ischemic conditions.

It also has positive effects on attenuating psychotic-, anxiety- and depressive-like behaviors.

Moreover, CBD affects synaptic plasticity and facilitates neurogenesis.

The mechanisms of these effects are still not entirely clear but seem to involve multiple pharmacological targets.

In the present review, we summarized the main biochemical and molecular mechanisms that have been associated with the therapeutic effects of CBD, focusing on their relevance to brain function, neuroprotection and neuropsychiatric disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26845349