Grant: Project Grant

Approximately one in four Canadians is affected by significant sleep problems that can diminish their health, alertness, safety and quality of life. The most common and serious of the sleep disorders have impairments of breathing as their root cause. One example is sleep apnea, which affects up to 20% of adults and is thought to be involved in some cases of sudden unexplained death in infancy. Sleep apnea is defined as cessation of breathing during sleep, and is typically caused by closure of the air passage in the throat in sleep due to relaxation of those breathing muscles (e.g., the tongue) whose activity normally keeps this air passage open. Episodes of breathing cessation in sleep can occur hundreds of times per night, each resulting in temporary suffocation that causes major sleep disruption. Understanding the brain mechanisms causing sleep apnea is important because of the adverse medical, societal and economic costs of this common disorder, such as increased strokes, angina and heart attacks, debilitating daytime sleepiness, increased traffic and work-related accidents, impaired work performance and decreased quality of life. Our research will identify the brain mechanisms that cause changes in breathing across wakefulness and sleep. Research will also identify how commonly used prescription and non-prescription sedating drugs (such as anesthetics, sleeping tablets, painkillers and alcohol) can also depress breathing and the waking-up responses to respiratory distress. This information will identify common mechanisms causing the prevalent problems of sleep and sedation-induced depression of breathing, and will guide pharmacological approaches aimed at preventing or reinstating breathing when it is depressed or fails.