Marijuana administration after a traumatic experience prevents post-traumatic stress symptoms
Administration of cannabinoids (in the form of synthetic marijuana) after experiencing a traumatic event blocks 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.
In the study, which Dr. Akirav conducted with research student Eti Ganon-Elazar, the researchers set out to examine how administering cannabinoids (synthetic marijuana) affects the development of PTSD-like symptoms in rats, whose physiological reactions to traumatic and stressful events is similar to human reactions.
In the first part of the study, the researchers exposed a group of rats to extreme stress, and observed 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 four 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.
A week later, the researchers examined the rats 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.
By contrast, the PTSD symptoms disappeared in the rats that were given marijuana 2 or 24 hours after experiencing trauma, even though these rats had also developed a high level of anxiety.
"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 suggest there is a particular window of time during which administering marijuana is effective. Because the human life span is significantly longer than that of rats, Dr. Akirav explained, one could assume that this window of time would be longer for humans.
The second stage of the study sought to understand the brain mechanism that is put into operation during the administering of marijuana. To do this, they repeated stage one of the experiment, but after the trauma they injected the synthetic marijuana directly into the amygdala area of the brain, the area known to be responsible for response to trauma. The researchers found that the marijuana blocked development of PTSD symptoms in these cases as well. From this the researchers were able to conclude that the effect of the marijuana is mediated by a CB1 receptor in the amygdala.
Recommend this story on Facebook, Twitter,
and Google +1:
Source: University of Haifa
- Use of cannabinoids could help post-traumatic stress disorder patientsWed, 4 Nov 2009, 9:37:52 EST
- Innovative therapies for treatment of post-traumatic stress disorderTue, 1 Sep 2009, 17:53:41 EDT
- Post-traumatic stress disorder: Psychological treatments may not prevent PTSDTue, 7 Jul 2009, 23:31:29 EDT
- Letters from home may help prevent post-traumatic stress disorder in happily married soldiersFri, 3 Jun 2011, 11:35:45 EDT
- Drug prevents post-traumatic stress syndromeMon, 6 Dec 2010, 12:04:45 EST
- Marijuana administration after a traumatic experience may prevent post-traumatic stress symptoms, rat study suggestsfrom Science DailyWed, 21 Sep 2011, 20:30:52 EDT
Latest Science NewsletterGet the latest and most popular science news articles of the week in your Inbox! It's free!
Learn more about
Check out our next project, Biology.Net
From other science news sites
Popular science news articles
No popular news yet
- From ocean to land: The fishy origins of our hips
- New method of finding planets scores its first discovery
- Invasive crazy ants are displacing fire ants in areas throughout southeastern US
- Seabird bones reveal changes in open-ocean food chain
- Scientific insurgents say 'Journal Impact Factors' distort science
No popular news yet
No popular news yet
- Stem cell transplant restores memory, learning in mice
- 2 landmark studies report on success of using image-guided brachytherapy to treat cervical cancer
- Researchers discover mushrooms can provide as much vitamin D as supplements
- Cutting back on sleep harms blood vessel function and breathing control
- Study: Low-dose aspirin stymies proliferation of 2 breast cancer lines