Description of Research Expertise

Current research involves studies of the neural mechanisms involved in the control of brainstem motoneurons that innervate upper airway muscles, particularly in reference to the control of the upper airway during rapid eye movement (REM) sleep and sleep-disordered breathing. For this, we use a urethane-anesthetized rat model in which REM sleep-like episodes are elicited by microinjections of carbachol (a cholinergic agonist) into a distinct site in the dorsal pontine tegmentum. These episodes can be triggered repeatedly and comprise events typical of REM sleep, such as cortical activation, hippocampal theta rhythm, silencing of pontine adrenergic neurons, slowing of the respiratory rate, and suppression of postural and upper airway motoneuronal activity. The role of the adrenergic (noradrenaline and serotonin) systems of the brainstem in the control of upper airway motoneurons (hypoglossal, pharyngeal, laryngeal), and its relation to REM sleep atonia, is currently being investigated using a variety of complementary neurophysiological, neuropharmacological and neuroanatomical techniques.