Our sense of smell is something we often take for granted. Besides allowing us to take in such wonderful aromas as flowers or fresh-baked cookies, our olfactory receptors help us keep a healthy appetite and tell us when to steer clear of hazards like pollution or spoiled food. Therefore, it’s concerning that olfactory dysfunction affects one in every hundred Americans under the age of 65, and over 50% of the population over 65. Fortunately, researchers at the University of Michigan, Ann Arbor have made recent breakthroughs in the restoration of smell to those who have lost it over time or were born without it.
When we are exposed to something that gives off smell, like the cookies pictures above, the odors are recognized by sensory neurons deep inside the nasal cavity. These neurons are cells from which project small hair-like structures called cilia. The cilia contain the receptors that bind the odors so that the sensory neuron knows what it’s dealing with. The sensory neuron then sends signals to the brain, and we perceive an aroma. A large cause of olfactory dysfunction is the loss of cilia. Without the cilia to trap the smells as they pass through the nose, the neurons don’t transmit anything and we don’t smell anything.
The University of Michigan has begun to solve this problem through gene therapy on mice. Jeffrey Martens, an associate professor of pharmacology at U-M as well as the leader of the team of researchers on the project, sums up their breakthrough in a University of Michigan article:
“Using gene therapy in a mouse model of cilia dysfunction, we were able to rescue and restore olfactory function, or sense of smell…Essentially, we induced the neurons that transmit the sense of smell to regrow the cilia they’d lost.”
In the experiment, mice that were lacking nasal cilia were the subjects of the gene therapy. These mice were usually underweight, as a loss of smell means a loss in appetite. However, after treatment, the mice’s average body weight increased by 60%, suggesting they were likely eating more. Also, the treated mice reacted more strongly to banana oil, whose smell generally repels mice, than they had before.
The implications of this discovery go even beyond our sense of smell. According to an article by the NIDCD (National Institute on Deafness and Other Communication Disorders), olfactory dysfunction is a member of a class of genetic disorders known as ciliopathies, or ailments caused by the lack of cilia. Cilia aren’t restricted to the nose: in fact, scientists believe that every cell in the body can grow at least one cilium. The absence of cilia in other parts of the body can lead to polycystic kidney disease and retinitis pigmentosa (which causes vision impairment and blindness), for example. The director of the NIDCD, James Battey, Jr., believes that the University of Michigan study “set the stage for therapeutic approaches to treating diseases that involve cilia dysfunction in other organ systems, many of which can be fatal if left untreated.” The process of restoring cilia will likely prove instrumental in the treatment of this class of disorders moving forward.
Research like this pays off at the University of Michigan, where research spending increased by $37.5 million to reach $1.27 billion for its most recent fiscal year. This information is courtesy of http://www.ur.umich.edu; to receive a detailed funding report on the University of Michigan, Ann Arbor, please click this button:
Biotechnology Calendar, Inc. will be returning to the University of Michigan in July 2013 for its Ann Arbor BioResearch Product Faire™ on July 18th, 2013. Biotechnology Calendar is a full service event company that has produced on-campus, life science research trade shows nationwide for the past 20 years. We plan and promote each event to bring the best products and services to the finest research campuses across the country. If you are a university researcher or a laboratory product vendor, consider attending one of our on-campus trade shows: here is our 2013 schedule.