The anxiolytic-like effects of cannabidiol injected into the bed nucleus of the stria terminalis are mediated by 5-HT1A receptors.

“Cannabidiol (CBD) is a non-psychotomimetic compound from Cannabis sativa that induces anxiolytic-like effects in rodents and humans after systemic administration. Previous results from our group showed that CBD injection into the bed nucleus of the stria terminalis (BNST) attenuates conditioned aversive responses. The aim of this study was to further investigate the role of this region on the anxiolytic effects of the CBD. Moreover, considering that CBD can activate 5-HT1A receptors, we also verified a possible involvement of these receptors in those effects.

CONCLUSIONS:

These results give further support to the proposal that BNST is involved in the anxiolytic-like effects of CBD observed after systemic administration, probably by facilitating local 5-HT1A receptor-mediated neurotransmission.”

http://www.ncbi.nlm.nih.gov/pubmed/20945065

5-HT1A receptors are involved in the cannabidiol-induced attenuation of behavioural and cardiovascular responses to acute restraint stress in rats.

“Cannabidiol (CBD) is a non-psychotomimetic compound from Cannabis sativa which induces anxiolytic- and antipsychotic-like effects in rodents. These effects could be mediated by facilitation of the endocannabinoid system or by the activation of 5-HT(1A) receptors. As either of these mechanisms could promote adaptation to inescapable stress, the aim of the present work was to test the hypothesis that CBD would attenuate the autonomic and behavioural consequences of restraint stress (RS). We also investigated if the responses to CBD depended on activation of 5-HT(1A) receptors.

Cannabidiol (CBD)… cannabinoid generally found in relatively high concentrations in cannabis, exhibits a somewhat different pharmacology compared with THC. CBD attenuates the psychotomimetic and anxiogenic effects of THC in humans.

 Moreover, systemic administration of CBD induced antipsychotic and anxiolytic-like effects…

CONCLUSION AND IMPLICATIONS:

The results suggest that CBD can attenuate acute autonomic responses to stress and its delayed emotional consequences by facilitating 5-HT(1A) receptor-mediated neurotransmission.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2697769/

 

Involvement of 5HT1A receptors in the anxiolytic-like effects of cannabidiol injected into the dorsolateral periaqueductal gray of rats.

“Cannabidiol (CBD) is a non-psychotomimetic constituent of Cannabis sativa plant that induces anxiolytic effects… In addition, since CBD has been shown to inhibit anandamide metabolism, CB1 receptors could also be involved in the effects of this cannabinoid…

CBD injected into the dorsolateral periaqueductal gray (dlPAG) produced anxiolytic-like effects… The anxiolytic effect of CBD was confirmed in the  Vogel conflict test (VCT)…

CONCLUSION:

These results suggest the CBD interacts with 5HT1A receptors to produce anxiolytic effects in the dlPAG.”

http://www.ncbi.nlm.nih.gov/pubmed/18446323

Cannabidiol blocks long-lasting behavioral consequences of predator threat stress: possible involvement of 5HT1A receptors.

“Posttraumatic stress disorder (PTSD) is an incapacitating syndrome that follows a traumatic experience. Predator exposure promotes long-lasting anxiogenic effect in rodents, an effect related to symptoms found in PTSD patients. Cannabidiol (CBD) is a non-psychotomimetic component of Cannabis sativa with anxiolytic effects. The present study investigated the anti-anxiety actions of CBD administration in a model of PTSD…

 Repeated administration of CBD prevented long-lasting anxiogenic effects promoted by a single predator exposure…

 In conclusion, predator exposure promotes long-lasting up-regulation of 5HT1A receptor gene expression in the hippocampus and frontal cortex. Repeated CBD administration prevents the long-lasting anxiogenic effects observed after predator exposure probably by facilitating 5HT1A receptors neurotransmission.

Our results suggest that CBD has beneficial potential for PTSD treatment and that 5HT1A receptors could be a therapeutic target in this disorder.”

http://www.ncbi.nlm.nih.gov/pubmed/22979992

Differential role of anandamide and 2-arachidonoylglycerol in memory and anxiety-like responses.

“Cannabinoid agonists are potential therapeutic agents because of their antinociceptive and anxiolytic-like effects…

These results dissociate the role of anandamide and 2-arachidonoylglycerol in memory consolidation and anxiety and reveal the interest of cannabinoid receptor 2 as a novel target for the treatment of anxiety-related disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/21684528

Mitigation of post-traumatic stress symptoms by Cannabis resin: a review of the clinical and neurobiological evidence.

“It is known from clinical studies that some patients attempt to cope with the symptoms of post-traumatic stress disorder (PTSD) by using recreational drugs. This review presents a case report of a 19-year-old male patient with a spectrum of severe PTSD symptoms, such as intense flashbacks, panic attacks, and self-mutilation, who discovered that some of his major symptoms were dramatically reduced by smoking cannabis resin. The major part of this review is concerned with the clinical and preclinical neurobiological evidence in order to offer a potential explanation of these effects on symptom reduction in PTSD.

This review shows that recent studies provided supporting evidence that PTSD patients may be able to cope with their symptoms by using cannabis products. Cannabis may dampen the strength or emotional impact of traumatic memories through synergistic mechanisms that might make it easier for people with PTSD to rest or sleep and to feel less anxious and less involved with flashback memories.

The presence of endocannabinoid signalling systems within stress-sensitive nuclei of the hypothalamus, as well as upstream limbic structures (amygdala), point to the significance of this system for the regulation of neuroendocrine and behavioural responses to stress.

 Evidence is increasingly accumulating that cannabinoids might play a role in fear extinction and antidepressive effects. It is concluded that further studies are warranted in order to evaluate the therapeutic potential of cannabinoids in PTSD.”

http://www.ncbi.nlm.nih.gov/pubmed/22736575

Anxiolytic-like effect of cannabidiol in the rat Vogel conflict test.

“Cannabidiol (CBD) is a major constituent of the Cannabis sativa plant. It inhibits the anxiogenic activity of high doses of Delta9-tetrahydrocannabinol and induces anxiolytic-like effects. However, the mechanisms underlying the actions of CBD are unknown. Therefore, the aim of the present study was to test the effects of CBD in the Vogel test, a widely used animal model of anxiety. 

 In conclusion, CBD induced an anticonflict effect not mediated by benzodiazepine receptors or by non-specific drug interference on nociceptive threshold or water consumption.

These results reinforce the hypothesis that this cannabinoid has anxiolytic properties.”

http://www.ncbi.nlm.nih.gov/pubmed/16876926

Role in Anxiety Behavior of the Endocannabinoid System in the Prefrontal Cortex

“Increasing evidence that low doses of cannabinoid agonists reduce anxiety-like behaviors in mice and rats is being reported, thus suggesting an anxiolytic role for the endogenous cannabinoid signaling. In line with this hypothesis, pharmacological agents that enhance the endogenous cannabinoid signaling exert anxiolytic-like actions…

  These findings support an anxiolytic role for physiological increases in AEA in the PFC, whereas more marked increases or decreases of this endocannabinoid might lead to an anxiogenic response due to TRPV1 stimulation or the lack of CB1 activation, respectively.”

http://cercor.oxfordjournals.org/content/18/6/1292.long

GABAergic and endocannabinoid dysfunction in anxiety – future therapeutic targets?

“With a lifetime prevalence of up to 25% anxiety disorders are among the most frequently occurring psychiatric disorders. The etiology of anxiety is considered to be multifactorial with an interaction of neurobiological, psychological and environmental factors. With regard to neurobiological factors, several neurochemical systems and neuroanatomical circuits have been discussed to be involved. In particular, anxiety might be a result of insufficient inhibitory control, pointing towards a major role of the gamma-amino-butyric acid (GABA) system in these disorders. Preclinical and clinical studies discuss a decreased GABAergic inhibition in anxiety and patients with anxiety disorders. In view of these findings it is intriguing that benzodiazepines, which currently represent the most potent and powerful anxiolytic agents, act through an enhancement of GABAergic inhibition targeting the GABAA receptor. Thus, it has been suggested that the GABAergic system might represent a promising future target for new pharmacologic strategies for the treatment of anxiety. Closely linked to the GABAergic system is the endocannabinoid system, which might also play an important role in this group of disorders. The endocannabinoid system has particularly been involved in extinction learning, suggesting a key role of this system in the process of fear extinction. In this paper, both the GABAergic and the endocannabinoid system will be reviewed with regard to their role in anxiety and anxiety disorders in humans with particular attention to findings from genetic and neuroimaging studies. Moreover, both systems will be discussed as potential therapeutic targets.”

http://www.ncbi.nlm.nih.gov/pubmed/19075727

The anxiolytic effect of cannabidiol on chronically stressed mice depends on hippocampal neurogenesis: involvement of the endocannabinoid system.

“Cannabidiol (CBD), the main non-psychotomimetic component of the plant Cannabis sativa, exerts therapeutically promising effects on human mental health such as inhibition of psychosis, anxiety and depression. However, the mechanistic bases of CBD action are unclear. Here we investigate the potential involvement of hippocampal neurogenesis in the anxiolytic effect of CBD in mice subjected to 14 d chronic unpredictable stress (CUS). Repeated administration of CBD (30 mg/kg i.p., 2 h after each daily stressor) increased hippocampal progenitor proliferation and neurogenesis in wild-type mice. Ganciclovir administration to GFAP-thymidine kinase (GFAP-TK) transgenic mice, which express thymidine kinase in adult neural progenitor cells, abrogated CBD-induced hippocampal neurogenesis. CBD administration prevented the anxiogenic effect of CUS in wild type but not in GFAP-TK mice as evidenced in the novelty suppressed feeding test and the elevated plus maze. This anxiolytic effect of CBD involved the participation of the CB1 cannabinoid receptor, as CBD administration increased hippocampal anandamide levels and administration of the CB1-selective antagonist AM251 prevented CBD actions. Studies conducted with hippocampal progenitor cells in culture showed that CBD promotes progenitor proliferation and cell cycle progression and mimics the proliferative effect of CB1 and CB2 cannabinoid receptor activation. Moreover, antagonists of these two receptors or endocannabinoid depletion by fatty acid amide hydrolase overexpression prevented CBD-induced cell proliferation.

 These findings support that the anxiolytic effect of chronic CBD administration in stressed mice depends on its proneurogenic action in the adult hippocampus by facilitating endocannabinoid-mediated signalling.”

http://www.ncbi.nlm.nih.gov/pubmed/23298518