Cannabinoids Inhibit Behavioral And Endocrine Alteration Developments

In recent times, cannabinoids have emerged as a possible treatment option for stress and anxiety-related disorders such as post traumatic stress disorder (PTSD). A research was aimed to examine whether cannabinoid receptor activation may inhibit the effects of traumatic stress on the development of behavioral and neuroendocrine measures in a rat model of PTSD, the single-prolonged stress (SPS) model.

During the research, rats were injected with the CB1/CB2 receptor agonist WIN55,212-2 (WIN) systemically or into the basolateral amygdala (BLA) at varying time points following SPS exposure and were tested a week later for inhibitory avoidance (IA) conditioning and extinction, acoustic startle response (ASR), hypothalamic-pituitary-adrenal (HPA) axis function, and anxiety levels.

It was revealed that SPS exposure improved conditioned avoidance and impaired extinction while increasing ASR, negative feedback on the HPA axis, and anxiety. WIN (0.5 mg/kg) administered intraperitoneally 2 or 24 h (but not 48 h) after SPS inhibited the trauma-induced alterations in IA conditioning and extinction, ASR potentiation, and HPA axis inhibition. SPS-induced alterations in IA and ASR were prevented by WIN microinjected into the BLA (5 μg/side). The effects were blocked by intra-BLA co-administration of the CB1 receptor antagonist AM251 (0.3 ng/side) and suggested the involvement of CB1 receptors.

It was suggested by the findings that there could be an optimal time-window for intervention treatment with cannabinoids after a highly-stressful event exposure and some preventive effects induced by WIN are possible of being mediated by the activation of CB1 receptors in the BLA. It was also revealed by the research findings that cannabinoids may serve as a pharmacological treatment of stress and trauma-related disorders.

Department of Psychology, University of Haifa, Haifa, Israel

PTSD Patients Helped By Use Of Cannabinoids

Medical-Marijuana-PTSDAccording to a study carried out at the Learning and Memory Lab in the University of Haifa’s Department of Psychology, the use of cannabinoids (marijuana) could assist in the treatment of post-traumatic stress disorder patients.

The study, which was carried out by research student Eti Ganon-Elazar under the supervision of Dr. Irit Akirav, was published in the Journal of Neuroscience.

The result of experiencing a traumatic event, in most cases, is the appearance of medical and psychological symptoms that affect various functions, but which pass. However, some 10 to 30 percent of people experiencing a traumatic event develop post-traumatic stress disorder, a condition in which the patient continues to suffer stress symptoms for months and even years after the traumatic event.

The symptoms of post-traumatic stress disorder (PTSD) include reawakened trauma, avoidance of anything that could recall the trauma, and psychological and physiological disturbances.

The study carried out by Dr. Akirav and research student Eti Ganon-Elazar was aimed to examine the efficiency of cannabinoids as a medical treatment for coping with post-traumatic stress. A synthetic form of marijuana that has similar properties to the natural plant was used by researchers a rat model was chosen that represents similar physiological responses to stress to that of humans.

It was revealed that marijuana cancelled out the symptoms of stress in rats and surfacing of stress symptoms was prevented, regardless of when exactly the injection was administered.

“The results of our research should encourage psychiatric investigation into the use of cannabinoids in post-traumatic stress patients,” said Dr. Akirav and added the study results how that cannabinoids can play an important role in stress-related disorders.

University of Haifa (2009, November 4). Use Of Cannabinoids Could Help Post-traumatic Stress

Cannabinoids Prevent Post-Traumatic Stress Symptoms

Neuropsychopharmacology journalAdministration of cannabinoids, in the form of synthetic marijuana, after experiencing a traumatic event is useful in blocking the development of post-traumatic stress disorder (PTSD)-like symptoms in rats, according to a new study conducted at the University of Haifa and published in the journal Neuropsychopharmacology.

“We found that there is a ‘window of opportunity’ during which administering synthetic marijuana helps deal with symptoms simulating PTSD in rats,” said Dr. Irit Akirav of the University of Haifa’s Department of Psychology, who led the study.

During the study that Dr. Akirav conducted with research student Eti Ganon-Elazar, the researchers set out to evaluate how administering cannabinoids (synthetic marijuana) affects the development of PTSD-like symptoms in rats, whose physiological reactions to traumatic and stressful events are similar to human reactions.

In study’s first part, the researchers exposed a group of rats to extreme stress, and found that the rats did indeed display symptoms resembling PTSD in humans, such as an enhanced startle reflex, impaired extinction learning, and disruption of the negative feedback cycle of the stress-influenced HPA axis. The rats were then divided into 4 groups: one was given no marijuana at all; the second was given a marijuana injection two hours after being exposed to a traumatic event, the third group after 24 hours, and the fourth group after 48 hours.

The researchers examined the rats a week later and found that the group that had not been administered marijuana and the group that got the injection 48 hours after experiencing trauma continued to display PTSD symptoms as well as a high level of anxiety. The PTSD symptoms disappeared in the rats that were given marijuana 2 or 24 hours after experiencing trauma.

“This indicates that the marijuana did not erase the experience of the trauma, but that it specifically prevented the development of post-trauma symptoms in the rat model,” said Dr. Akirav, who added that the results hinted that there is a particular window of time during which administering marijuana is effective.

During second stage of the study, the researchers repeated stage one of the experiment, but after the trauma they injected the synthetic marijuana directly into the amygdala area of the brain and found that the marijuana blocked development of PTSD symptoms in these cases as well.

Eti Ganon-Elazar, Irit Akirav. Cannabinoids Prevent the Development of Behavioral and Endocrine Alterations in a Rat Model of Intense Stress. Neuropsychopharmacology, 2011; DOI: 10.1038/npp.2011.204