Neural mechanisms of obstructive sleep apnea, a common sleep-related breathing disorder, are incompletely understood. Hypoglossal motoneurons, which provide tonic and inspiratory activation of genioglossus (GG) muscle (a major upper airway dilator), receive catecholaminergic input from medullary A1/C1 neurons. We aimed to determine the contribution of A1/C1 neurons in control of GG muscle during sleep and wakefulness. To do so, we placed injections of a viral vector into DBH-cre mice to selectively express the hMD4i inhibitory chemoreceptors in A1/C1 neurons. Administration of the hM4Di ligand, clozapine-N-oxide (CNO), in these mice decreased GG muscle activity during NREM sleep (F1,1,3=17.1, p<0.05); a similar non-significant decrease was observed during wakefulness. CNO administration had no effect on neck muscle activity, respiratory parameters or state durations. In addition, CNO-induced inhibition of A1/C1 neurons did not alter the magnitude of the naturally occurring depression of GG activity during transitions from wakefulness to NREM sleep. These findings suggest that A1/C1 neurons have a net excitatory effect on GG activity that is most likely mediated by hypoglossal motoneurons. However, the activity of A1/C1 neurons does not appear to contribute to NREM sleep-related inhibition of GG muscle activity, suggesting that A1/C1 neurons regulate upper airway patency in a state-independent manner.

Purpose Obstructive sleep apnea is a prevalent sleep disorder among older adults. Oral appliances are increasingly prescribed as therapy for obstructive sleep apnea. Adherence to oral appliance therapy is highly variable. Based on value-expectancy theory and other social psychological theories, adherence to oral appliance therapy may be influenced by patients’ perceived effectiveness of the therapy, self-efficacy, and availability of social support. We examined these perceptions among older adults with obstructive sleep apnea who were prescribed oral appliance therapy. Methods We mailed surveys to all patients aged > 65 years who had been prescribed oral appliance therapy for obstructive sleep apnea over the prior 36 months at a Veterans Affairs medical center. We examined frequencies for items assessing perceived effectiveness, self-efficacy, and social support for nightly use of oral appliances from friends, family, or healthcare staff). Findings Thirty-nine individuals responded (response rate 30%; mean age 71 (+/− 6) years; 97% male). Thirty-six percent of the respondents perceived regular use of oral appliance therapy to be effective in managing obstructive sleep apnea; 39% agreed that they felt confident about using oral appliances regularly; 41% felt supported by people in their life in using oral appliance therapy; and 38% agreed healthcare staff will help them use their oral appliance regularly. This was despite our finding that more than half (65%) of patients believed they would use their oral appliance regularly. Implications Although oral appliance therapy is increasingly prescribed for obstructive sleep apnea, only about one-third of older adults perceive it to be an effective treatment, are confident about oral appliance use, or believe they will receive needed support. Future research is needed to better understand older adults’ perceptions so that interventions can be designed to improve the effectiveness of oral appliances, their self-efficacy for using oral appliances, and their social support for this therapy, which may, in turn, improve oral appliance therapy adherence.