Effect of Desipramine on Upper Airway Collapsibility and Genioglossus Muscle Activity in Patients With Obstructive Sleep Apnea - Study B

Two overnight sleep studies, a placebo night and a drug night, will be performed approximately one week apart in random order. The placebo or drug will be administered 2 hours before lights out. At least 15 minutes of quiet wakefulness will be recorded to quantify the participant's EMG GG activity while awake and at sleep onset (alpha-theta transition at the electroencephalogram). During the second part of the night, the participants will be connected to a modified continuous positive airway pressure (CPAP) machine (Pcrit3000, Respironics) which can provide a wide range of pressures between 20 and -20 cmH2O in order to modify upper airway pressure and measure pharyngeal critical collapsing pressure (Pcrit), ventilation at 0 cmH2O when UA muscle are passive and active as well as change in EMG GG as a function of epiglottic pressure (muscle responsiveness). Apnea-hypopnea index (AHI) will be calculated in each night from the part of the study off CPAP.