Your Brain On Cannabis: Part Three

Welcome to the final part of this three part series on the effects of cannabis on the brain, and today we look at marijuana as medicine.

There are several well-documented beneficial effects of marijuana including the amelioration of nausea and vomiting, stimulation of hunger in chemotherapy and AIDS patients, lowered intraocular eye pressure (shown to be effective for treating glaucoma), as well as general analgesic effects (pain reliever).

The first treatment to emerge from understanding cannabinoids is the drug rimonabant, recently approved in Europe to treat obesity and related metabolic conditions. The drug works by binding to receptors in the brain and body organs to block cannabinoid action. Studies have shown that an overactivated cannabinoid system in brain areas like the hypothalamus -which is involved in appetite increases food intake and fat accumulation. Rimonabant and similar compounds reduce cannabinoid overstimulation to help normalize appetite, body weight and fat, and also cholesterol levels. Drugs that decrease cannabinoid action also may cause anxiety or depression-side effects scientists are working to combat.

Research is underway to determine if rimonabant also will help smokers and heavy drinkers quit. Scientists believe that rimonabant could work in these conditions by reducing levels of the chemical dopamine in the brain’s motivation centers, which nicotine and other addictive drugs trigger.

In 2011, an oromucosal spray for Multiple Sclerosis patients became licensed for use as a medicine in Canada and parts of Europe, allowing it to be routinely prescribed by doctors. This drug reduces the pain, tremor, and muscle spasms associated with this disease.

Synthesized cannabinoids are also sold as prescription drugs, including Marinol (dronabinol) in the United States and Germany and Cesamet (nabilone) in Canada, Mexico, the United States and the United Kingdom. Canada, Spain, The Netherlands, Austria and fourteen states in the US have legalized some form of cannabis for medicinal use.

I regularly visit schools to explain how addictive drugs including cannabis affect the brain.

Click to arrange a speaking engagement.

For those interested in the topic of marijuana abuse more information can be found at: http://drugabuse.gov/ResearchReports/Marijuana/marijuana3.html


Your Weekly Neuroscience Update

You’re running late for work and you can’t find your keys. What’s really annoying is that in your frantic search, you pick up and move them without realising. This may be because the brain systems involved in the task are working at different speeds, with the system responsible for perception unable to keep pace. So says Grayden Solman and his colleagues at the University of Waterloo in Ontario, Canada.

Scientists have now discovered how different brain regions cooperate during short-term memory  and in other research -findings that a prion-like protein plays a key role in storing long-term memories

Memories in our brains are maintained by connections between neurons called “synapses”. But how do these synapses stay strong and keep memories alive for decades? Neuroscientists at the Stowers Institute for Medical Research have discovered a major clue from a study in fruit flies: Hardy, self-copying clusters or oligomers of a synapse protein are an essential ingredient for the formation of long-term memory.

Researchers reveal a novel mechanism through which the brain may become more reluctant to function as we grow older.

New research from Uppsala University shows that reduced insulin sensitivity is linked to smaller brain size and deteriorated language skills in seniors. The findings are now published in the scientific journal Diabetes Care.

Age-related delays in neural timing are not inevitable and can be avoided or offset with musical training, according to a new study from Northwestern University. The study is the first to provide biological evidence that lifelong musical experience has an impact on the aging process.

Could brain size determine whether you are good at maintaining friendships? Researchers are suggesting that there is a link between the number of friends you have and the size of the region of the brain – known as the orbital prefrontal cortex – that is found just above the eyes. A new study, published today in the journal Proceedings of the Royal Society B, shows that this brain region is bigger in people who have a larger number of friendships.

Scientists have long believed that human speech is processed towards the back of the brain’s cerebral cortex, behind auditory cortex where all sounds are received – a place famously known as Wernicke’s area after the German neurologist who proposed this site in the late 1800s based on his study of brain injuries and strokes. But, now, research that analyzed more than 100 imaging studies concludes that Wernicke’s area is in the wrong location. The site newly identified is about 3 centimeters closer to the front of the brain and on the other side of auditory cortex – miles away in terms of brain architecture and function.

New research from Cold Spring Harbor Laboratory (CSHL) might help explain how a gene mutation found in some autistic individuals leads to difficulties in processing auditory cues and paying spatial attention to sound.

Neuroscientists may one day be able to hear the imagined speech of a patient unable to speak due to stroke or paralysis, according to University of California, Berkeley, researchers.

Cocaine-dependent men and women might benefit from different treatment options, according to a study conducted by Yale School of Medicine researchers.

New research finds problems that require a flash of illumination to solve are best approached during the time of day when you’re not at your peak.

Researchers for the first time are documenting the basic wiring of the brain, the complex relationships among billions of neurons that are responsible for reason, memory and emotion. The work eventually could lead to better understanding of schizophrenia, autism, multiple sclerosis and other disorders.

Weekly Round-Up

Blogging may have psychological benefits for teens suffering from social anxiety, improving their self-esteem and helping them relate better to their friends, according to new research published by the American Psychological Association.

Scientists at The Scripps Research Institute have discovered that DNA stays too tightly wound in certain brain cells of schizophrenic subjects. The findings suggest that drugs already in development for other diseases might eventually offer hope as a treatment for schizophrenia and related conditions in the elderly.

Deep depression that fails to respond to any other form of therapy can be moderated or reversed by stimulation of areas deep inside the brain.

Radiology researchers at The University of Texas Health Science Center at Houston (UTHealth) have found evidence that multiple sclerosis affects an area of the brain that controls cognitive, sensory and motor functioning apart from the disabling damage caused by the disease’s visible lesions.

People with diets high in several vitamins or in omega 3 fatty acids are less likely to have the brain shrinkage associated with Alzheimer’s disease than people whose diets are not high in those nutrients, according to a new study published in the December 28, 2011, online issue of Neurology®, the medical journal of the American Academy of Neurology.

When you experience a new event, your brain encodes a memory of it by altering the connections between neurons. This requires turning on many genes in those neurons. Now, MIT neuroscientists have identified what may be a master gene that controls this complex process. The findings, described in the Dec. 23 issue of Science, not only reveal some of the molecular underpinnings of memory formation — they may also help neuroscientists pinpoint the exact locations of memories in the brain.

New drop-in centre for patients with neurological disorders

TV3 presenter Sinead Desmond, pictured at the launch of a patient drop-in centre by the Dublin Neurological Institute this week

TV3 presenter Sinead Desmond spoke this week of her near-fatal brain haemorrhage nearly three years ago. At the launch of Ireland’s first drop-in centre for people with neurological disorders, she spoke of her gratitude at emerging  unscathed with no brain damage from the experience.

“I have been blessed with a 100pc recovery,” she said. “I met people since who had similar brain haemorrhages and suffered from brain injuries. The recovery can be tough.”

The new centre is housed within the Dublin Neurological Institute at the Mater Hospital in Eccles Street. People with neurological conditions, which include epilepsy, stroke, acquired brain injury, multiple sclerosis, dementia and motor neurone disease, can call in without having to be referred by a GP. They will be able to speak to a specialist nurse, and get free medical information and support.

National Brain Awareness Week runs until Sunday.