The nervous gut
When we talk about the nervous system, we usually think of the brain, the spinal cord, and associated nerves. But there's actually another complex set of nerves in our body. The gastrointestinal system has its own set: the enteric nervous system. There are as many nerve cells in the enteric nervous system as there are in the spinal cord. This rich nervous environment is the subject of AHFMR Scientist Dr. Keith Sharkey's research. He holds the Crohn's and Colitis Chair in IBD Research at the University of Calgary.
"One of most interesting aspects of the enteric nervous system is the constant two-way communication between the gut and the brain, and the brain and the gut. It's not just the brain affecting the gut; the gut also affects the brain. Sorting this out is fascinating work."
Dr. Sharkey's interest in the enteric nervous system has taken his research in a number of directions, one of which is the study of a particular class of chemical messengers called endocannabinoids. These molecules, which are produced in the body, act on the same receptors as cannabinoids (the active ingredient in marijuana). Dr. Sharkey's lab has made some discoveries that illuminate the role of endocannabinoids in controlling nausea and vomiting. In 2005 his team found a new cannabinoid receptor in the brain. Unlike the first receptor, which was discovered in 1990, this one reduces nausea and vomiting without mind-altering effects.
"Simply knowing about these receptors is just scratching the surface," notes Dr. Sharkey. "Now we are working on understanding how they are regulated. If we could get a handle on this, we would be in a position to target these receptors and use endocannabinoids therapeutically for treating inflammation, suppressing appetite, and increasing metabolism. There's a lot of potential."
In addition to his research on the gastrointestinal system, Dr. Sharkey studies the neurobiology of obesity. He examines the communication between the brain and the enteric nervous system and how that communication controls food intake. Specifically, he is looking at stimuli produced by the gut that make us want to eat or to stop eating. These stimuli may be the key to preventing overeating.
"Understanding the digestive system is a much bigger challenge than many people realize," says Dr. Sharkey. "The digestive system has a number of jobs to do: digest food in the right place and at the right time; protect us from the digestive process itself, which is inherently able to digest us; and protect us from toxic or hazardous elements in our food. And it is all so elegantly regulated."
New partnership boosts IBD research
AHFMR and the Crohn's and Colitis Foundation of Canada (CCFC) have signed a partnership agreement aimed at stepping up research on inflammatory bowel disease (IBD). The agreement will enable more doctoral students and post-doctoral fellows to be supported financially while they carry out research on IBD. The CCFC and AHFMR will offer four training awards over the next two years. The awards are intended primarily for Alberta students who want to study at the doctoral level or do post-doctoral training, elsewhere in Canada or abroad.