Modulation of Long-Term Potentiation of Cortico-Amygdala Synaptic Responses and Auditory Fear Memory by Dietary Polyunsaturated Fatty Acid.

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“Converging evidence suggests that an imbalance of ω3 to ω6 polyunsaturated fatty acid (PUFA) in the brain is involved in mental illnesses such as anxiety disorders.

We previously reported that the dietary ratio of ω3 to ω6 PUFA alters this ratio in the brain, and influences contextual fear memory.

In addition to behavioral change, enhancement of cannabinoid CB1 receptor-mediated short-term synaptic plasticity and facilitation of the agonist sensitivity of CB1 receptors have been observed in excitatory synaptic responses in the basolateral nucleus of the amygdala (BLA).

These results suggest that the balance of ω3 to ω6 PUFA has an impact on fear memory and cortico-amygdala synaptic plasticity, both in a CB1 receptor-dependent manner.”

Interaction between interleukin-1β and type-1 cannabinoid receptor is involved in anxiety-like behavior in experimental autoimmune encephalomyelitis.

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“Mood disorders, including anxiety and depression, are frequently diagnosed in multiple sclerosis (MS) patients, even independently of the disabling symptoms associated with the disease.

Anatomical, biochemical, and pharmacological evidence indicates that type-1 cannabinoid receptor (CB1R) is implicated in the control of emotional behavior and is modulated during inflammatory neurodegenerative diseases such as MS and experimental autoimmune encephalomyelitis (EAE).

We investigated whether CB1R could exert a role in anxiety-like behavior in mice with EAE. We performed behavioral, pharmacological, and electrophysiological experiments to explore the link between central inflammation, mood, and CB1R function in EAE.

Overall, results of the present investigation indicate that synaptic dysfunction linked to CB1R is involved in EAE-related anxiety and motivation-based behavior and contribute to clarify the complex neurobiological mechanisms underlying mood disorders associated to MS.

Collectively, our data contribute to clarify the synaptic and, at least in part, molecular basis of mood disturbances in EAE and, possibly, MS. Understanding the neurobiological underpinning of anxiety-like behavior in EAE mice is of crucial importance to optimize the treatment of mood disturbance in MS and, possibly, other neuroinflammatory diseases.

In this direction, targeting the endocannabinoid system may be a valid therapeutic tool for the treatment of both psychiatric and motor symptoms in MS patients.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5009553/

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

“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

Acute Stress Suppresses Synaptic Inhibition and Increases Anxiety via Endocannabinoid Release in the Basolateral Amygdala.

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“Stress and glucocorticoids stimulate the rapid mobilization of endocannabinoids in the basolateral amygdala (BLA).

Cannabinoid receptors in the BLA contribute to anxiogenesis and fear-memory formation. We tested for rapid glucocorticoid-induced endocannabinoid regulation of synaptic inhibition in the rat BLA.

Together, these findings suggest that acute stress causes a long-lasting suppression of synaptic inhibition in BLA neurons via a membrane glucocorticoid receptor-induced release of 2-AG at GABA synapses, which contributes to stress-induced anxiogenesis.

We show that acute stress increases anxiety-like behavior via an endocannabinoid-dependent mechanism centered in the BLA.

The stress-induced endocannabinoid modulation of synaptic transmission in the BLA contributes, therefore, to the stress regulation of anxiety, and may play a role in anxiety disorders of the amygdala.”

http://www.ncbi.nlm.nih.gov/pubmed/27511017

Cannabinoids biology: the search for new therapeutic targets.

“Cannabinoids, in the form of marijuana plant extracts, have been used for thousands of years for a wide variety of medical conditions, ranging from general malaise and mood disorders to more specific ailments, such as pain, nausea, and muscle spasms.

The discovery of tetrahydrocannabinol, the active principal in marijuana, and the identification and cloning of two cannabinoid receptors (i.e., CB1 and CB2) has subsequently led to biomedical appreciation for a family of endocannabinoid lipid transmitters.

The biosynthesis and catabolism of the endocannabinoids and growing knowledge of their broad physiological roles are providing insight into potentially novel therapeutic targets.

Compounds directed at one or more of these targets may allow for cannabinoid-based therapeutics with limited side effects and abuse liability.”

http://www.ncbi.nlm.nih.gov/pubmed/16809476

Multiple Mechanistically Distinct Modes of Endocannabinoid Mobilization at Central Amygdala Glutamatergic Synapses

“The central amygdala (CeA) is a key structure at the limbic-motor interface regulating stress responses and emotional learning. Endocannabinoid (eCB) signaling is heavily implicated in the regulation of stress-response physiology and emotional learning processes; however, the role of eCBs in the modulation of synaptic efficacy in the CeA is not well understood. Here we describe the subcellular localization of CB1 cannabinoid receptors and eCB synthetic machinery at glutamatergic synapses in the CeA and find that CeA neurons exhibit multiple mechanistically and temporally distinct modes of postsynaptic eCB mobilization. These data identify a prominent role for eCBs in the modulation of excitatory drive to CeA neurons and provide insight into the mechanisms by which eCB signaling and exogenous cannabinoids could regulate stress responses and emotional learning.”

http://www.cell.com/neuron/abstract/S0896-6273(14)00017-8

Cannabis Targets Receptors in the Amygdala Linked to Anxiety

“Marijuana may hijack cannabinoid receptors in the amygdala to reduce anxiety.”

“An international group of researchers led by Vanderbilt University has discovered for the first time that there are cannabinoid receptors in the amygdala. The amygdala is one of the primary brain regions involved in regulating anxiety and the flight-or-fight response.

“The discovery may help explain why marijuana users say they take the drug mainly to reduce anxiety” said Sachin Patel, M.D., Ph.D., the paper’s senior author and professor of Psychiatry and of Molecular Physiology and Biophysics at Vanderbilt. He said, “this could be highly important for understanding how cannabis exerts its behavioral effects.”

The study titled, “Multiple Mechanistically Distinct Modes of Endocannabinoid Mobilization at Central Amygdala Glutamatergic Synapses” is published in the March 2014 issue of the journal Neuron.”

https://www.psychologytoday.com/blog/the-athletes-way/201403/cannabis-targets-receptors-in-the-amygdala-linked-anxiety

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

“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

Fluorinated Cannabidiol Derivatives: Enhancement of Activity in Mice Models Predictive of Anxiolytic, Antidepressant and Antipsychotic Effects.

“Cannabidiol (CBD) is a major Cannabis sativa constituent, which does not cause the typical marijuana psychoactivity. However, it has been shown to be active in a numerous pharmacological assays, including mice tests for anxiety, obsessive-compulsive disorder, depression and schizophrenia. In human trials the doses of CBD needed to achieve effects in anxiety and schizophrenia are high. We report now the synthesis of 3 fluorinated CBD derivatives, one of which, 4′-F-CBD (HUF-101) (1), is considerably more potent than CBD in behavioral assays in mice predictive of anxiolytic, antidepressant, antipsychotic and anti-compulsive activity. Similar to CBD, the anti-compulsive effects of HUF-101 depend on cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27416026

Cannabinoid receptor agonism suppresses tremor, cognition disturbances and anxiety-like behaviors in a rat model of essential tremor.

“Cognitive and motor disturbances are serious consequences of tremor induced by motor disorders. Despite a lack of effective clinical treatment, some potential therapeutic agents have been used to alleviate the cognitive symptoms in the animal models of tremor.

In the current study, the effects of WIN55, 212-2 (WIN), a cannabinoid receptor (CBR) agonist, on harmaline-induced motor and cognitive impairments was studied.

The neuroprotective and anxiolytic effects of WIN demonstrated in the current study can be offered cannabinoid receptor (CBR) agonism as a potential neuroprotective agent in the treatment of patients with tremor that manifest mental dysfunctions.”

http://www.ncbi.nlm.nih.gov/pubmed/27317835