Category Archives: Post-Traumatic Stress Disorder (PTSD)

Dorsal hippocampus cannabinoid type 1 receptors modulate the expression of contextual fear conditioning in rats: Involvement of local glutamatergic/nitrergic and GABAergic neurotransmissions.

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“The cannabinoid receptor type 1 (CB1) is highly expressed in the dorsal portion of hippocampus – a brain region that has been involved in the control of conditioned emotional response (CER) in the contextual fear conditioning (CFC) model.

These responses are characterized by increased freezing behavior and autonomic parameters. Moreover, CB1 receptors activation negatively modulate the release of several neurotransmitters, including glutamate and GABA, which also have been related to modulation of CER. Therefore, our aim was to investigate the involvement of CB1 receptors in the dorsal hippocampus on CER expression.

Our results suggest that increased CER evoked by CB1 blockade in the dorsal hippocampus depends on NMDA receptor activation and NO formation. Moreover, a fine-tune control promoted by GABAergic and glutamatergic mechanisms in this brain area modulate the CER after CB1 blockade.”

http://www.ncbi.nlm.nih.gov/pubmed/27591981

Cannabinoids and post-traumatic stress disorder: clinical and preclinical evidence for treatment and prevention.

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“There is substantial evidence from studies in humans and animal models for a role of the endocannabinoid system in the control of emotional states. Several studies have shown an association between exposure to trauma and substance use. Specifically, it has been shown that there is increased prevalence of cannabis use in post-traumatic stress disorder (PTSD) patients and vice versa.

Clinical studies suggest that PTSD patients may cope with their symptoms by using cannabis. This treatment-seeking strategy may explain the high prevalence of cannabis use among individuals with PTSD.

Preliminary studies in humans also suggest that treatment with cannabinoids may decrease PTSD symptoms including sleep quality, frequency of nightmares, and hyperarousal.

Studies in animal models have shown that cannabinoids can prevent the effects of stress on emotional function and memory processes, facilitate fear extinction, and have an anti-anxiety-like effect in a variety of tasks.

Moreover, cannabinoids administered shortly after exposure to a traumatic event were found to prevent the development of PTSD-like phenotype.

In this article, we review the existing literature on the use of cannabinoids for treating and preventing PTSD in humans and animal models.

There is a need for large-scale clinical trials examining the potential decrease in PTSD symptomatology with the use of cannabis.

In animal models, there is a need for a better understanding of the mechanism of action and efficacy of cannabis. Nevertheless, the end result of the current clinical and preclinical data is that cannabinoid agents may offer therapeutic benefits for PTSD.”

http://www.ncbi.nlm.nih.gov/pubmed/27551883

Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation.

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“Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories.

We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation.

Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific cell types revealed that the CB1 receptor population specifically in dopamine β-hydroxylase (DBH)-expressing cells is both necessary and sufficient for stress-induced impairment of memory consolidation, but CB1 receptors present in other neuronal populations are not involved.

Strikingly, pharmacological manipulations in mice expressing CB1 receptors exclusively in DBH+ cells revealed that both hippocampal and peripheral receptors mediate the impact of stress on memory consolidation.

Thus, CB1 receptors on adrenergic and noradrenergic cells provide previously unrecognized cross-talk between central and peripheral mechanisms in the stress-dependent regulation of nonemotional memory consolidation, suggesting new potential avenues for the treatment of cognitive aspects on stress-related disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/27528659

New Study Finds Marijuana To Be Effective Against Depression, Migraine and Anxiety

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“Research has suggested that cannabis may be a promising treatment option for a number of different physical and mental health conditions, from post-traumatic stress disorder to chronic pain. A study released this week suggests that depression , anxiety and migraine can be added to that list.

Neuroscientists from the University of Buffalo’s Research Institute on Addictions found that endocannabinoids — chemical compounds in the brain that activate the same receptors as THC, an active compound in marijuana — may be helpful in treating depression, anxiety and migraine that results from chronic stress.

In studies on rats, the researchers found that chronic stress reduced the production of endocannabinoids, which affect our cognition, emotion and behavior, and have been linked to reduced feelings of pain and anxiety, increases in appetite and overall feelings of well-being. The body naturally produces these compounds, which are similar to the chemicals in cannabis. Reduction of endocannabinoid production may be one reason that chronic stress is a major risk factor in the development of depression.

Then, the research team administered marijuana cannabinoids to the rats, finding it to be an effective way to restore endocannabinoid levels in their brains — possibly, thereby, alleviating some symptoms of depression.

“Using compounds derived from cannabis — marijuana — to restore normal endocannabinoid function could potentially help stabilize moods and ease depression,” lead researcher Dr. Samir Haj-Dahmane said in a university press release.

Recent research around marijuana’s effect on symptoms of post-traumatic stress disorder further bolsters the Buffalo neuroscientists’ findings, since both disorders involve the way the brain responds to stress. A study published last year in the journal Neuropsychopharmacology, for instance, found synthetic cannabinoids triggered changes in brain centers associated with traumatic memories in rats, preventing some of the behavioral and physiological symptoms of PTSD. Another study published last year found that patients who smoked cannabis experienced a 75 percent reduction in PTSD symptoms.

However, it’s important to note that the relationship between marijuana and depression  is complex. Some research has suggested that regular and heavy marijuana smokers are at a higher risk for depression, although a causal link between cannabis use and depression has not been established. More studies are needed in order to determine whether, and how, marijuana might be used in a clinical context for patients with depression.”  http://painphysicianjournal.co/2016/06/30/new-study-finds-marijuana-to-be-effective-against-depression-migraine-and-anxiety/

New Study Finds Marijuana To Be Effective Against Depression, Migraine and Anxiety

The endocannabinoid system and Post Traumatic Stress Disorder (PTSD): From preclinical findings to innovative therapeutic approaches in clinical settings.

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“Post-Traumatic Stress Disorder (PTSD) is a psychiatric chronic disease developing in individuals after the experience of an intense and life-threatening traumatic event. The post-traumatic symptomatology encompasses alterations in memory processes, mood, anxiety and arousal.

There is now consensus in considering the disease as an aberrant adaptation to traumatic stress. Pharmacological research, aimed at the discovery of new potential effective treatments, has lately directed its attention towards the “so-called” cognitive enhancers. This class of substances, by modulating cognitive processes involved in the development and/or persistence of the post-traumatic symptomatology, could be of great help in improving the outcome of psychotherapies and patients’ prognosis.

In this perspective, drugs acting on the endocannabinoid system are receiving great attention due to their dual ability to modulate memory processes on one hand, and to reduce anxiety and depression on the other.

The purpose of the present review is to offer a thorough overview of both animal and human studies investigating the effects of cannabinoids on memory processes.

First, we will briefly describe the characteristics of the endocannabinoid system and the most commonly used animal models of learning and memory. Then, studies investigating cannabinoid modulatory influences on memory consolidation, retrieval and extinction will be separately presented, and the potential benefits associated with each approach will be discussed.

In the final section, we will review literature data reporting beneficial effects of cannabinoid drugs in PTSD patients.”

http://www.ncbi.nlm.nih.gov/pubmed/27456243

Modulation of cannabinoid signaling by hippocampal 5-HT4 serotonergic system in fear conditioning.

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“Behavioral studies have suggested a key role for the cannabinoid system in the modulation of conditioned fear memory. Likewise, much of the literature has revealed that the serotonergic system affects Pavlovian fear conditioning and extinction. A high level of functional overlap between the serotonin and cannabinoid systems has also been reported.

To clarify the interaction between the hippocampal serotonin (5-HT4) receptor and the cannabinoid CB1 receptor in the acquisition of fear memory, the effects of 5-HT4 agents, arachidonylcyclopropylamide (ACPA; CB1 receptor agonist), and the combined use of these drugs on fear learning were studied in a fear conditioning task in adult male NMRI mice.

Pre-training intraperitoneal administration of ACPA (0.1 mg/kg) decreased the percentage of freezing time in both context- and tone-dependent fear conditions, suggesting impairment of the acquisition of fear memory. Pre-training, intra-hippocampal (CA1) microinjection of RS67333, a 5-HT4 receptor agonist, at doses of 0.1 and 0.2 or 0.2 µg/mouse impaired contextual and tone fear memory, respectively. A subthreshold dose of RS67333 (0.005 µg/mouse) did not alter the ACPA response in either condition.

Moreover, intra-CA1 microinjection of RS23597 as a 5-HT4 receptor antagonist did not alter context-dependent fear memory acquisition, but it did impair tone-dependent fear memory acquisition. However, a subthreshold dose of the RS23597 (0.01 µg/mouse) potentiated ACPA-induced fear memory impairment in both conditions.

Therefore, we suggest that the blockade of hippocampal 5-HT4 serotonergic system modulates cannabinoid signaling induced by the activation of CB1 receptors in conditioned fear.”

http://www.ncbi.nlm.nih.gov/pubmed/27296273

Cannabidiol Modulates Fear Memory Formation through Interactions with Serotonergic Transmission in the Mesolimbic System.

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“Emerging evidence suggests that the largest phytochemical component of cannabis, cannabidiol (CBD), may possess pharmacotherapeutic properties in the treatment of neuropsychiatric disorders.

CBD has been reported to functionally interact with both the mesolimbic dopamine (DA) and serotonergic (5-HT) receptor systems.

Our findings demonstrate a novel NAcVTA circuit responsible for the behavioral and neuronal effects of CBD within the mesolimbic system via functional interactions with serotonergic 5-HT1A receptor signalling.”

http://www.ncbi.nlm.nih.gov/pubmed/27296152

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

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“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 for posttraumatic stress disorder: A neurobiological approach to treatment.

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“The endocannabinoid system is intricately involved in regulation of the neurobiological processes, which underlie the symptomatology of posttraumatic stress disorder (PTSD). This article discusses the neurobiological underpinnings of PTSD and the use of cannabis for treating PTSD in the New Mexico Medical Cannabis Program.”

The Use of Medicinal Marijuana for Posttraumatic Stress Disorder: A Review of the Current Literature.

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“This study seeks to understand the current literature regarding the use of medicinal marijuana in the treatment of posttraumatic stress disorder (PTSD).

Analysis revealed that most reports are correlational and observational in basis with a notable lack of randomized, controlled studies.

Many of the published studies suggest a decrease in PTSD symptoms with marijuana use… there is a growing amount of neurobiological evidence and animal studies suggesting potential neurologically based reasons for the reported efficacy.

CONCLUSIONS:

Posttraumatic stress disorder is 1 of the approved conditions for medicinal marijuana in some states. While the literature to date is suggestive of a potential decrease in PTSD symptomatology with the use of medicinal marijuana, there is a notable lack of large-scale trials, making any final conclusions difficult to confirm at this time.”

http://www.ncbi.nlm.nih.gov/pubmed/26644963

http://www.thctotalhealthcare.com/category/post-traumatic-stress-disorder-ptsd/