Faculty Bibliography

Neural representations of the external world are constructed and updated in a manner that depends on behavioral context. For neocortical networks, this contextual information is relayed by a diverse range of neuromodulatory systems, which govern attention and signal the value of internal state variables such as arousal, motivation, and stress. Neuromodulators enable cortical circuits to differentially process specific stimuli and modify synaptic strengths in order to maintain short- or long-term memory traces of significant perceptual events and behavioral episodes. One of the most important subcortical neuromodulatory systems for attention and arousal is the noradrenergic locus coeruleus. Here we report that the noradrenergic system can enhance behavior in rats performing a self-initiated auditory recognition task, and optogenetic stimulation of noradrenergic locus coeruleus neurons accelerated the rate at which trained rats began correctly responding to a change in reward contingency. Animals successively progressed through distinct behavioral epochs, including periods of perseverance and exploration that occurred much more rapidly when animals received locus coeruleus stimulation. In parallel, we made recordings from primary auditory cortex and found that pairing tones with locus coeruleus stimulation led to a similar set of changes to cortical tuning profiles. Thus both behavioral and neural responses go through phases of adjustment for exploring and exploiting environmental reward contingencies. Furthermore, behavioral engagement does not necessarily recruit optimal locus coeruleus activity.

Skill learning is fundamental to the acquisition of many complex behaviors that emerge during development. For example, years of practice give rise to perceptual improvements that contribute to mature speech and language skills. While fully honed learning skills might be thought to offer an advantage during the juvenile period, the ability to learn actually continues to develop through childhood and adolescence, suggesting that the neural mechanisms that support skill learning are slow to mature. To address this issue, we asked whether the rate and magnitude of perceptual learning varies as a function of age as male and female gerbils trained on an auditory task. Adolescents displayed a slower rate of perceptual learning as compared to their young and mature counterparts. We recorded auditory cortical neuron activity from a subset of adolescent and adult gerbils as they underwent perceptual training. While training enhanced the sensitivity of most adult units, the sensitivity of many adolescent units remained unchanged, or even declined across training days. Therefore, the average rate of cortical improvement was significantly slower in adolescents as compared to adults. Both smaller differences between sound-evoked response magnitudes and greater trial-to-trial response fluctuations contributed to the poorer sensitivity of individual adolescent neurons. Together, these findings suggest that elevated sensory neural variability limits adolescent skill learning.Significance Statement:The ability to learn new skills emerges gradually as children age. This prolonged development, often lasting well into adolescence, suggests that children, teens, and adults may rely on distinct neural strategies to improve their sensory and motor capabilities. Here, we found that practice-based improvement on a sound detection task is slower in adolescent gerbils than in younger or older animals. Neural recordings made during training revealed that practice enhanced the sound sensitivity of adult cortical neurons, but had a weaker effect in adolescents. This latter finding was partially explained by the fact that adolescent neural responses were more variable than in adults. Our results suggest that one mechanistic basis of adult-like skill learning is a reduction in neural response variability.

Chronic inflammation of the salivary glands from pathologic conditions such as Sjögren's syndrome can result in glandular destruction and hyposalivation. To understand which molecular factors may play a role in clinical cases of salivary gland hypofunction, we developed an aquaporin 5 (AQP5) Cre mouse line to produce genetic recombination predominantly within the acinar cells of the glands. We then bred these mice with the TNF-αglo transgenic line to develop a mouse model with salivary gland-specific overexpression of TNF-α; which replicates conditions seen in sialadenitis, an inflammation of the salivary glands resulting from infection or autoimmune disorders such as Sjögren's syndrome. The resulting AQP5-Cre/TNF-αglo mice display severe inflammation in the salivary glands with acinar cell atrophy, fibrosis, and dilation of the ducts. AQP5 expression was reduced in the salivary glands, while tight junction integrity appeared to be disrupted. The immune dysregulation in the salivary gland of these mice led to hyposalivation and masticatory dysfunction.

Perineural invasion (PNI), the neoplastic invasion of nerves, is a common pathological finding in head and neck cancer that is associated with poor clinical outcomes. PNI is a histological finding of tumor cell infiltration and is distinct from perineural tumor spread (PNTS), which is macroscopic tumor involvement along a nerve extending from the primary tumor that is by definition more advanced, being radiologically or clinically apparent. Despite widespread acknowledgement of the prognostic significance of PNI/PNTS, the mechanisms underlying its pathogenesis remain largely unknown, and specific therapies targeting nerve invasion are lacking. The use of radiation therapy for PNI/PNTS can improve local control and reduce devastating failures at the skull base. However, the optimal volumes to be delineated with respect to targeting cranial nerve pathways are not well defined, and radiation may carry risks of major toxicity secondary to the location of adjacent critical structures. Here we examine the pathogenesis of these phenomena, analyze the role of radiation in PNI/PNTS, and propose guidelines for radiation treatment design based on the best available evidence and the authors' collective experience in order to advance understanding and therapy of this ominous cancer phenotype.

Osseointegrated auditory devices (OADs) are hearing devices that use an external receiver/processor that stimulates bone conduction of sound via a titanium prosthesis that is drilled into the bone of the cranium. Since their introduction in 1977, OADs have undergone substantial evolution, including changes in manufacturing of the implant, improvements in the external sound processor, and simplification of implantation techniques. Expansion of criteria for patient candidacy for implantation has occurred corresponding with changes in the implants and processors.

Oropharyngeal carcinoma associated with the human papillomavirus is increasing in incidence and represents a unique head and neck disease with favorable treatment outcomes. This review evaluates the evolving role of radiotherapy in regional management with an overall goal of treatment de-escalation in the appropriate patient. Determining the optimal approach and selection factors for treatment de-escalation is under active investigation. Response to induction chemotherapy, refining adverse pathologic factors after a primary surgical approach, decreasing radiation dose with or without chemotherapy in the definitive or adjuvant settings as well as more selective nodal level irradiation all are current strategies for treatment de-escalation. This review details the likely changes in regional radiotherapy management for oropharyngeal carcinoma in the modern human papillomavirus era and discusses future approaches to patient selection with the goal of reducing toxicities while maintaining function preservation and quality of life in group of patients who are younger and healthier than traditional head and neck cancer patients.

A new category of hearing technology has emerged that comprises devices inserted deep into the ear canal. Although not implanted, they represent an extension of what is expected of a traditional hearing aid. There are advantages to these devices, but they are not suited for all individuals with hearing loss. This category consists of 2 devices currently available in the United States: Lyric (Phonak AG, Stafa, Switzerland) and Earlens (Earlens, Menlo Park, CA, USA).

Objectives/UNASSIGNED:To perform a needs-based assessment for tracheostomy care education for nonsurgical first responders in the hospital setting and to implement and assess the efficacy of a targeted tracheostomy educational program. Methods/UNASSIGNED:A prospective observational study conducted between October 2017 and May 2018 including emergency medicine (EM) residents, internal medicine (IM) residents, and intensive care unit (ICU) advanced practice providers at 2 tertiary hospitals. Needs-based assessments were conducted, leading to specialty specific curricula. One-hour educational sessions included didactics and case-based simulation. A pre- and posttest objective knowledge quiz and self-assessment were administered, and a posttest was repeated at 6 months. Results/UNASSIGNED:< .05) in mean objective knowledge score was seen across all groups between pre- and postintervention assessments with relative but not significant improvement at 6 months. There were significant increases in comfort level from pre- to postintervention. At 6-month follow-up, comfort level remained significantly increased for the majority of questions for the EM group and for select questions for IM and ICU advanced practice provider groups. Discussion/UNASSIGNED:Nonsurgeons are often first responders to critical airway situations yet receive limited formal education regarding tracheostomy. We demonstrated improvement in knowledge and comfort after a targeted educational module for tracheostomy care and management. Implications for Practice/UNASSIGNED:Although tracheostomy care is multidisciplinary, specialty-specific education may provide a more relevant foundation on which to build skills. Prompt and effective management of tracheostomy emergencies by first responders may improve patient safety and reduce mortality.

BACKGROUND:Awareness of disease status has been identified as a factor in the treatment decision-making process. Women with recurrent ovarian cancer are facing the challenge of making treatment decisions throughout the disease trajectory. It is not understood how women with ovarian cancer perceive their disease and subsequently make treatment decisions. PURPOSE/OBJECTIVE:The purpose of this phenomenological study was to understand the lived experience of women with recurrent ovarian cancer, how they understood their disease and made their treatment decisions. METHODS:A qualitative design with a descriptive phenomenological method was used to conduct 2 in-depth interviews with 12 women (n = 24 interviews). Each interview was ∼60 minutes and was digitally recorded and professionally transcribed. Data collection focused on patients' understanding of their disease and how patients participated in treatment decisions. A modified version of Colaizzi's method of phenomenological reduction guided data analysis. RESULTS:Three themes emerged to describe the phenomenon of being aware of disease status: (1) perceiving recurrent ovarian cancer as a chronic illness, (2) perceived inability to make treatment decisions, and (3) enduring emotional distress. CONCLUSIONS AND IMPLICATIONS/CONCLUSIONS:This study revealed how 12 women conceptualized recurrent ovarian cancer as a chronic disease and their perceived inability to make treatment decisions because of lack of information and professional qualifications, resulting in enduring emotional distress. Future research should replicate the study to confirm the persistence of the themes for racially, ethnically, and religiously diverse patient samples and to improve understanding of awareness of disease status and decision-making processes of patients.