Alyssa Huff

Seattle Children’s Research Institute · Center for Integrative Brain Research

Swallow and breathing are highly coordinated behaviors reliant on shared anatomical space and neural pathways. Incremental ascent to high altitudes results in hypoxia/hypocapnic conditions altering respiratory drive, however it is not known whether these changes also alter swallow. We examined the effect of incremental ascent (1045m, 3440m and 4371...

Purpose: Airway protective behaviors, like cough and swallow, deteriorate in many populations suffering from neurologic disorders. While coordination of these behaviors has been investigated in an animal model, it has not been tested in humans. Methods: We used a novel protocol, adapted from previous work in the cat, to assess cough and swallow...

Swallow-breathing coordination is influenced by changes in lung volume, which is modulated by feedback from both vagal and spinal sensory afferents. The purpose of this study was to manipulate feedback from these afferents, with and without a simultaneous mechanical challenge (chest compression), in order to assess the influence of each sensory pat...

Lung volume is modulated by sensory afferent feedback via vagal and spinal pathways. The purpose of this study was to systematically alter afferent feedback with and without a mechanical challenge (chest compression). We hypothesized that manipulation of afferent feedback by nebulization of lidocaine, extra-thoracic vagotomy, or lidocaine administr...

Rett syndrome (RTT), an X-chromosome-linked neurological disorder, is characterized by serious pathophysiology, including breathing and feeding dysfunctions, and alteration of cardiorespiratory coupling, a consequence of multiple interrelated disturbances in the genetic and homeostatic regulation of central and peripheral neuronal networks, redox s...

Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder that results in multiple bouts of intermittent hypoxia. OSA has many neurologic and systemic comorbidities including dysphagia, or disordered swallow and discoordination with breathing. However, the mechanism in which chronic intermittent hypoxia (CIH) causes dysphagia is...

Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder that results in multiple bouts of intermittent hypoxia. OSA has many neurologic and systemic comorbidities including dysphagia, or disordered swallow and discoordination with breathing. However, the mechanism in which chronic intermittent hypoxia (CIH) causes dysphagia is...

Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder that results in multiple bouts of intermittent hypoxia. OSA has many neurologic and systemic comorbidities including dysphagia, or disordered swallow and discoordination with breathing. However, the mechanism in which chronic intermittent hypoxia (CIH) causes dysphagia is...

Breathing needs to be tightly coordinated with upper airway behaviors, such as swallowing. Discoordination leads to aspiration pneumonia, the leading cause of death in neurodegenerative disease. Here we study the role of the Postinspiratory Complex (PiCo) in coordinating breathing and swallowing. Using optogenetic approaches in freely breathing- an...

Breathing needs to be tightly coordinated with upper airway behaviors, such as swallowing. Discoordination leads to aspiration pneumonia, the leading cause of death in neurodegenerative disease. Here, we study the role of the postinspiratory complex (PiCo) in coordinating breathing and swallowing. Using optogenetic approaches in freely breathing an...

Breathing needs to be tightly coordinated with upper airway behaviors, such as swallowing. Discoordination leads to aspiration pneumonia, the leading cause of death in neurodegenerative disease. Here, we study the role of the postinspiratory complex (PiCo) in coordinating breathing and swallowing. Using optogenetic approaches in freely breathing an...

Breathing needs to be tightly coordinated with upper airway behaviors, such as swallowing. Discoordination leads to aspiration pneumonia, the leading cause of death in neurodegenerative disease. Here, we study the role of the postinspiratory complex (PiCo) in coordinating breathing and swallowing. Using optogenetic approaches in freely breathing an...

Leigh Syndrome is a severe neurometabolic disorder and the most common form of mitochondrial disorder in the pediatric population. It has been linked to loss of function mutations in Ndufs4, the gene that codes for a subunit of the mitochondrial complex I. First signs of early-onset Leigh Syndrome (LS) include difficulty swallowing (dysphagia), suc...

Swallowing is a vital behavior that is coordinated with breathing involving rhythmogenic networks in the medulla, the preBötzinger complex (PreBötC) and postinspiratory complex (PiCo). These networks are critical for generating inspiratory and postinspiratory activity, respectively. Both areas also interact with neurons involved in autonomic contro...

Breathing needs to be tightly coordinated with upper airway behaviors, such as swallowing. Discoordination leads to aspiration pneumonia, the leading cause of death in neurodegenerative diseases. Here we study the role of the postinspiratory complex, (PiCo) in coordinating breathing and swallowing. Using optogenetic approaches in freely breathing-a...

Rett Syndrome is an X-linked neurological disorder characterized by behavioral and neurological regression, seizures, motor deficits, and dysautonomia. A particularly prominent presentation includes breathing abnormalities characterized by breathing irregularities, hyperventilation, repetitive breathholding during wakefulness, obstructive and centr...

The coordination of swallowing with breathing, in particular inspiration, is essential for homeostasis in most organisms. While much has been learned about the neuronal network critical for inspiration in mammals, the pre–Bötzinger complex (preBötC), little is known about how this network interacts with swallowing. Here we activate within the preBö...

Laryngeal function is vital to airway protection. While swallow is mediated by the brainstem, mechanisms underlying increased risk of dysphagia after cervical spinal cord injury (SCI) are unknown. We hypothesized that loss of descending phrenic drive affects swallow and breathing differently, and loss of ascending spinal afferent information alters...

The resting respiratory activity is generated by synchronized activity of a complex located within the brainstem. This contains a primary oscillator essential for the respiratory rhythmicity and is composed of pacemaker inspiratory neurons. However, recent studies suggest the postinspiratory complex (PiCo) is a novel respiratory oscillator which is...

Proper function of the larynx is vital to airway protection, including swallow. While the swallow reflex is controlled by the brainstem, patients with cervical spinal cord injuries (cSCI) are likely at increased risk of disordered swallow (dysphagia) and pneumonia, and the underlying mechanisms are unknown. We aimed to determine if acute spinal cor...

Swallow is a primitive behavior regulated by medullary networks, responsible for movement of food/liquid from the oral cavity to the esophagus. To investigate how functionally heterogeneous networks along the medullary intermediate reticular formation (IRt) and ventral respiratory column (VRC) control swallow, we electrically stimulated the nucleus...

Afferent feedback can appreciably alter the pharyngeal phase of swallow. In order to measure the stability of the swallow motor pattern during several types of alterations in afferent feedback, we assessed swallow during a conventional water challenge in four anesthetized cats, and compared that to swallows induced by fixed (20 Hz) and stochastic (...

Swallow and breathing are tightly coordinated behaviors in which disruption of this coordination leads to aspiration pneumonia, the leading cause of death in many adult and pediatric diseases. Little is known about the neural coordination of these two behaviors. Previous work in the respiratory column has shown activity in swallow‐related and breat...

Under resting conditions, breathing is characterized by inspiration and postinspiration. Located in the ventrolateral medulla, the preBötzinger Complex (pre‐BötC) is critical for generating the inspiratory phase of breathing. This microcircuit contains glutamatergic neurons derived from progenitor cells that are characterized by the transcription f...

Respiratory variability is important in order to respond to internal and external perturbations. While vagal afferents have been shown to be important for feedback during breathing, the influence of spinal afferents has not been as well described. We hypothesized that disruption of vagal and spinal afferents reduces respiratory variability during e...

The ventral respiratory column (VRC) contains heterogeneous neurons that generate and regulate respiration as well as other orofacial behaviors. In neonate SD rat, the VRC extends over 2 mm from the rostral margin of the facial nucleus (VIIn). In addition, networks that modulate breathing on a cycle‐to‐cycle basis are distributed along the dorsomed...

Swallow disorder (dysphagia) can cause aspiration and lead to pneumonia in a number of patient populations, including individuals with cervical spinal cord injury. Dysphagia is characterized by dysfunction in the swallow motor pattern, which is a sequential activation of muscles that propels the bolus into the esophagus and prevents entry into the...

Muscle position feedback, via receptors for stretch (muscle spindles) and force (golgi tendon organs), is critical for the muscular coordination and proprioception that is essential for most movements. Muscle spindles are innervated by gamma motoneurons that modulate their sensitivity to stretch. Recent reports suggest that 5‐HT 1D receptors can mo...

Atropine, a muscarinic acetylcholine receptor antagonist, is a commonly used drug to reduce mucous production during surgery. Because atropine blocks the parasympathetic action of acetylcholine, atropine may modulate the balance of parasympathetic and sympathetic activity. In jaw muscles, increased sympathetic drive decreases muscle contractility a...

Purpose While factors leading to hypoventilation have been well studied in Pompe disease, cough effectiveness and airway clearance practices are less understood. We aimed to identify significant factors that influence peak cough flow (PCF) in Pompe, and to detect whether pulmonary hygiene practices were reflective of reduced PCF. Methods This is a...

Anatomical connections are reported between the cerebellum and brainstem nuclei involved in swallow such as the nucleus tractus solitarius, nucleus ambiguus, and Kölliker-fuse nuclei. Despite these connections, a functional role of the cerebellum during swallow has not been elucidated. Therefore, we examined the effects of cerebellectomy on swallow...

The effects of cervical hemisection on swallow have not been determined. We hypothesized that cervical hemisection would increase swallow excitability and shift the pattern of swallow breathing coordination to maintain pharyngeal clearance. Electromyograms of the mylohyoid, geniohyoid, thyrohyoid, thyroarytenoid, thyropharyngeus, cricopharyngeus an...

Action of the diaphragm is necessary for negative force production during breathing and cough. However, the effect of cervical spinal cord injury on action of the diaphragm during cough is not known. It was hypothesized that C2 hemisection would result in a loss of cough excitability and depression of the diaphragm during breathing and cough. Elect...

Swallow‐breathing coordination is critical for maintaining a clear airway during the act of swallowing. Swallows can occur during all phases of breathing, however, they are primarily initiated during expiration. The interaction between central pattern generators for swallowing and breathing contribute to this phase preference. While hypercapnia has...

The effect of pharyngeal and esophageal distention on swallow phase transition has not been fully elucidated. In quadrupeds we hypothesize pharyngeal to esophageal (P:E) ratio is dependent on distention of the pharynx and/or esophagus to trigger a phase transition. To this effect videofluoroscopy was performed on 8 cats using liquid and puree consi...

Rehabilitation of cough is now moving under the purview of speech-language pathology as our understanding of the relationship between disorders of cough and swallow increases. The purpose of this review is to provide a guide in understanding the mechanisms of weak or disordered cough in Parkinson's disease, and mechanisms for why expiratory muscle...

This study evaluated the antilisterial activity of hops beta acids (HBA) and their impact on the quality and sensory attributes of ham. Commercially cured ham slices were inoculated with unstressed- and acid-stress-adapted (ASA)-L. monocytogenes (2.2 to 2.5 log CFU/cm(2) ), followed by no dipping (control), dipping in deionized (DI) water, or dippi...