Cannabis prevents negative behavioral, physiological effects of traumatic events
September 4, 2014
Science Daily/University of Haifa
Administering synthetic marijuana (cannabinoids) soon after a traumatic event can prevent PTSD-like (post-traumatic stress disorder) symptoms in rats, caused by the trauma and by trauma reminders. This is according to a new study conducted by Nachshon Korem and Irit Akirav of the Department of Psychology at the University of Haifa, which was published in the journal Neuropsychopharmacology. "The importance of this study is that it contributes to the understanding of the brain basis of the positive effect cannabis has on PTSD and thus supports the necessity to perform human trials to examine potential ways to prevent the development of PTSD and anxiety disorders in response to a traumatic event," the researchers noted.
According to the Israel Medical Association approximately nine percent of the population suffers from post-traumatic stress disorder, whereas among at-risk populations such as combat soldiers, prisoners, victims of assault, citizens in lines of confrontation, etc., the percentages are even higher. A common phenomenon among those who suffer from trauma is that exposure to a "trauma reminder" -- an event that is not traumatic in essence but that evokes the memory of the experience of the traumatic event -- can further heighten the negative effects of the trauma. For example, for a person who has developed post-traumatic syndromes as a result of "Color Red" sirens (air raid sirens), a trauma reminder can occur following a loud car alarm.
In previous studies performed by Dr. Irit Akirav, she discovered that the use of cannabinoids within a specific time window after the traumatic event has occurred reduces PTSD symptoms in rats. In this current study, conducted by Dr. Irit Akirav together with the doctoral student Nachshon Korem, the researchers aimed to examine whether the use of cannabinoids may also moderate the effects of trauma in cases of exposure to trauma reminders. The researchers chose rats because of their great physiological similarity to humans in the way they respond to stressful and traumatic events.
During the first half of the experiment, the rats underwent the traumatic event of receiving an electric shock and were exposed to trauma reminders on the third and fifth days of the trial. After the event, and within the time window found in earlier studies, some of the rats were injected with a cannabinoid substance. The rats then went through extinction procedures for trauma (a conditional psychological procedure similar to exposure therapy in humans, the purpose of which is to cope with post-trauma symptoms).
From the findings it became clear that the rats that were injected with the cannabinoid substance showed no PTSD symptoms such as impaired extinction learning, increased startle response, changes in sensitivity to pain and impaired plasticity in the brain's reward center (the nucleus accumbens), compared to those not injected with the drug. The researchers added that the rats that were injected with the drug showed better results compared to rats who received sertraline (an antidepressant of the SSRI group) a substance that is used in the treatment of PTSD with limited success in reducing symptoms. In fact, for some of the symptoms, the rats that were injected with the drug showed similar behavior to rats exposed to trauma but that were not exposed to trauma reminders. In other words -- cannabis made the effects of trauma reminders "disappear."
Once they found the moderating effect of cannabis on behavioral aspects, the study aimed to examine the neurobiological basis for the improvement caused by the drug. It was found that rats who were exposed to trauma and to trauma reminders showed an increase in the expression of two receptors in the brain associated with emotional processing: the CB1 receptor, a receptor in the brain that cannabinoids are known to bind to, and receptor GR, the receptor associated with exposure to stress. On the other hand, in rats that received cannabinoids, the increase in the expression of these two receptors was prevented in the hippocampus and prefrontal cortex, areas involved in forming and saving traumatic memories.
"The findings of our study suggest that the connectivity within the brain's fear circuit changes following trauma, and the administration of cannabinoids prevents this change from happening. This study can lead to future trials in humans regarding possible ways to prevent the development of PTSD and anxiety disorders in response to a traumatic event," the researchers concluded.
https://www.sciencedaily.com/releases/2014/09/140904084252.htm
Medical marijuana may ease some MS; Little evidence for other complementary or alternative therapies
March 24, 2014
Science Daily/American Academy of Neurology (AAN)
A new guideline from the American Academy of Neurology suggests that there is little evidence that most complementary or alternative medicine therapies (CAM) treat the symptoms of multiple sclerosis (MS). However, the guideline states the CAM therapies oral cannabis, or medical marijuana pills, and oral medical marijuana spray may ease patients' reported symptoms of spasticity, pain related to spasticity and frequent urination in multiple sclerosis (MS). The guideline, which is published in the March 25, 2014, print issue of Neurology®, the medical journal of the American Academy of Neurology, states that there is not enough evidence to show whether smoking marijuana is helpful in treating MS symptoms.
The guideline looked at CAM therapies, which are nonconventional therapies used in addition to or instead of doctor-recommended therapies. Examples include oral cannabis, or medical marijuana pills and oral medical marijuana spray, ginkgo biloba, magnetic therapy, bee sting therapy, omega-3 fatty acids and reflexology.
"Using different CAM therapies is common in 33 to 80 percent of people with MS, particularly those who are female, have higher education levels and report poorer health," said guideline lead author Vijayshree Yadav, MD, MCR, with Oregon Health & Science University in Portland and a member of the American Academy of Neurology. "People with MS should let their doctors know what types of these therapies they are taking, or thinking about taking."
For most CAM therapies, safety is unknown. There is not enough information to show if CAM therapies interact with prescription MS drugs. Most CAM therapies are not regulated by the Food and Drug Administration (FDA). Dronabinol and nabilone are synthetic forms of key ingredients in marijuana. The FDA approved both drugs as treatments for nausea and vomiting associated with cancer chemotherapy that do not respond to standard treatments. Dronabinol also is approved for loss of appetite associated with weight loss in patients with AIDS.
The guideline found that certain forms of medical marijuana, in pill or oral spray form only, may help reduce patients' reported spasticity symptoms, pain due to spasticity, and frequent urination but not loss of bladder control. The therapy may not help reduce tremor. Long-term safety of medical marijuana use in pill or oral spray is not known. Most of the studies are short, lasting six to 15 weeks. Medical marijuana in pill or oral spray form may cause side effects, some of which can be serious. Examples are seizures, dizziness, thinking and memory problems as well as psychological problems such as depression. This can be a concern given that some people with MS are at an increased risk for depression or suicide. Both doctors and patients must weigh the possible side effects that medical marijuana in pill or oral spray form can cause.
Among other CAM therapies studied for MS, ginkgo biloba might possibly help reduce tiredness but not thinking and memory problems. Magnetic therapy may also help reduce tiredness but not depression.
Reflexology might possibly help ease symptoms such tingling, numbness and other unusual skin sensations. Bee sting therapy, a low-fat diet with fish oil, and a therapy called the Cari Loder regimen all do not appear to help MS symptoms such as disability, depression and tiredness. Bee stings can cause a life-threatening allergic reaction and dangerous infections.
Moderate evidence shows that omega-3 fatty acids such as fish oil likely do not reduce relapses, disability, tiredness or MRI brain scan lesions, nor do they improve quality of life in people with MS.
https://www.sciencedaily.com/releases/2014/03/140324181258.htm
University of Saskatchewan Research Suggests Marijuana Analogue Stimulates Brain Cell Growth
October 16, 2005
Science Daily/University of Saskatchewan
A synthetic substance similar to ones found in marijuana stimulates cell growth in regions of the brain associated with anxiety and depression, pointing the way for new treatments for these diseases, according to University of Saskatchewan medical research published today in The Journal of Clinical Investigation.
Xia Zhang, an associate professor in the U of S neuropsychiatry research unit, led the team that tested the effects of HU-210, a potent synthetic cannabinoid similar to a group of compounds found in marijuana. The synthetic version is about 100 times as powerful as THC, the compound responsible for the high experienced by recreational users.
The team found that rats treated with HU-210 on a regular basis showed neurogenesis – the growth of new brain cells in the hippocampus. This region of the brain is associated with learning and memory, as well as anxiety and depression.
The effect is the opposite of most legal and illicit drugs such as alcohol, nicotine, heroin, and cocaine.
“Most ‘drugs of abuse’ suppress neurogenesis,” Zhang says. “Only marijuana promotes neurogenesis.”
Current theory states that depression may be sparked when too few new brain cells are grown in the hippocampus. It is unclear whether anxiety is part of this process, but if true, HU-210 could offer a treatment for both mood disorders by stimulating the growth of new brain cells.
But Zhang cautions that HU-210 is only one of many cannabinoids. His previous work with marijuana shows that while the plant may contain medicinal compounds, they come in the same package as those that cause symptoms such as acute memory impairment, addiction, and withdrawal. Also, the HU-210 used in the study is highly purified.
“This is a very potent cannabinoid oil,” Zhang says. “It’s not something that would be available on the street.”
Marijuana has been used for recreational and medicinal purposes for centuries, evoking public interest and controversy along the way. As a medicine, the plant is used to ease pain in multiple sclerosis patients, combat nausea in cancer patients, and stimulate appetite in people afflicted with AIDS. It has also been used to treat epilepsy and stroke.
Zhang’s work is the latest product of the U of S Neural Systems and Plasticity Research Group (http://www.usask.ca/neuralsystems/group.htm), a multidisciplinary effort by researchers from the Colleges of Arts and Science, Engineering, Kinesiology, Medicine, Pharmacy and Nutrition, and Veterinary Medicine. The group collaborates to study the function of neural systems, from nerves to brain, in living organisms. In particular, they look at how these systems change over time with experience.
Zhang’s research is supported by a grant from the Canadian Institutes of Health Research (CIHR), as well as a CIHR New Investigator Award. The Saskatchewan Health Research Foundation provided funding support to establish the Neural Systems and Plasticity Research Group, as well as post-doctoral fellowship awards to research team members Wen Jiang and Shao-Ping Ji.
https://www.sciencedaily.com/releases/2005/10/051016083817.htm