Hypoglossal nerve stimulation in a pre-clinical anesthetized rabbit model relevant to OSA

Abstract

We tested the functional effects of hypoglossal (CNXII) stimulation in the anesthetized rabbit before and after injections of saline into the tongue base to obstruct the airway. Data (n = 6) show little or no effect of CN XII trunk stimulation; however, medial branch stimulation (20-100 Hz; 50-500 μs pulse width, and incremental increases from 10 μA) reduced upper airway resistance. Medial branch stimulation was less effective in reducing resistance than anterior advancement of the hyoid. Endoscopic viewing (n-3) of the retropalate showed this region as the narrowest and dynamically changed by anterior hyoid displacement, with less evident effects than CNXII stimulation. We conclude that under these conditions CNXII medial branch stimulation reduces airway resistance, especially after induced obstruction.

Sciatic nerve stimulation and its effects on upper airway resistance in the anesthetized rabbit model relevant to sleep apnea

“…It was not until pressure exceeded 50% of the maximum baseline pressure that flow exceeded baseline flow. This was opposite to the effect observed during hypoglossal nerve stimulation, which increased the slope of the curve without the appearance of a maximal flow plateau (3).…”

“…In summary, there was not an improvement in airway patency associated with sciatic nerve stimulation, but it does not suggest that there was a reduction in airway patency. In contrast, we found that the flow at the low driving pressures was elevated without any detectable flow limitation when applying hypoglossal nerve stimulation (3).…”

“…2). Persistent effects were not observed in these same animals during hypoglossal nerve stimulation (3).…”

“…We recently developed a rabbit model that we believe can test OSA neurotherapies as it is bigger than rodents and its upper airway more like that of humans (3). We used an anesthetized model to determine if stimulation could reduce upper airway resistance, and compared the effects of this to stimulation of the hypoglossal nerve.…”

Pdk-1/Hif-1α Ratios Define Geniohyoid Muscle Fiber Phenotypes

“…However, a question remains: what would occur in the GH muscle exposed to hypoxic conditions when Hif-1α level in the muscle is controlled low genetically? This query is important, because the GH muscle is a constantly used upper airway dilator, enlarging the pharyngeal lumen in rodents and humans, easing airflow in both species [14,15]. If GH muscle endurance in partial Hif-1 knockout (KO) mice can be improved in response to an IH challenge, as suggested [8], we could assist breathing in OSA patients travelling a high altitude using a comparable method.…”