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.