Faculty Bibliography

Rat ultrasonic vocalizations (USVs) have traditionally been used in psychosocial and psychobiological studies to understand emotion, social behavior, cognition, and associative learning. However, recent studies have expanded the goal of USVs to include the study of the laryngeal system and the effects of disease processes on vocal sensorimotor control. Without the foundational understanding of the goals of this area of laryngological research, fundamental differences in study objectives between psychobehavioral and laryngological studies can easily be missed, leading to misconceptions and misinterpretations of the role USVs play in laryngology-focused studies. Standardization of terminology and methods are also needed to improve communication, enhance study replicability, and prevent ambiguity that can lead to misinterpretations of study objectives and findings in this line of research. The primary objective is to describe the role of USVs in studies of laryngeal anatomy and physiology, with a focus on their connections to the neuromuscular and neurological aspects of the laryngeal system, particularly in relation to vocal sensorimotor control and voice disorders. It is intended for novice investigators interested in laryngology-specific USV research. Researchers experienced in USV studies within the context of the larynx and vocal sensorimotor control first outline the development and refinement of various USV elicitation methods. They provide insights into how these approaches have been tested across different studies and laboratories. Finally, they advocate for standardizing terminology and methodologies to enhance study replicability, reduce ambiguity, and foster collaboration across research groups.

Cortical networks for the production of spoken language in humans are organized by phonetic features^1,2, such as articulatory parameters^3,4 and vocal pitch^5,6. Previous research has failed to find an equivalent forebrain representation in other species^7-11. To investigate whether this functional organization is unique to humans, here we performed population recordings in the vocal production circuitry of the budgerigar (Melopsittacus undulatus), a small parrot that can generate flexible vocal output^12-15, including mimicked speech sounds¹⁶. Using high-density silicon probes¹⁷, we measured the song-related activity of a forebrain region, the central nucleus of the anterior arcopallium (AAC), which directly projects to brainstem phonatory motor neurons^18-20. We found that AAC neurons form a functional vocal motor map that reflects the spectral properties of ongoing vocalizations. We did not observe this organizing principle in the corresponding forebrain circuitry of the zebra finch, a songbird capable of more limited vocal learning²¹. We further demonstrated that the AAC represents the production of distinct vocal features (for example, harmonic structure and broadband energy). Furthermore, we discovered an orderly representation of vocal pitch at the population level, with single neurons systematically selective for different frequency values. Taken together, we have uncovered a functional representation in a vertebrate brain that displays unprecedented commonalities with speech-related motor cortices in humans. This work therefore establishes the parrot as an important animal model for investigating speech motor control and for developing therapeutic solutions for addressing a range of communication disorders^22,23.

Embryonic development in many species, including case reports in humans, can be temporarily halted before implantation during a process called diapause. Facultative diapause occurs under conditions of maternal metabolic stress such as nursing. While molecular mechanisms of diapause have been studied, a natural inducing factor has yet to be identified. Here, we show that oxytocin induces embryonic diapause in mice. We show that gestational delays were triggered during nursing or optogenetic stimulation of oxytocin neurons simulating nursing patterns. Mouse blastocysts express oxytocin receptors, and oxytocin induced delayed implantation-like dispersion in cultured embryos. Last, oxytocin receptor-knockout embryos transferred into wild-type surrogates had low survival rates during diapause. Our results indicate that oxytocin coordinates timing of embryonic development with uterine progression through pregnancy, providing an evolutionarily conserved mechanism for ensuring successful reproduction.

OBJECTIVE:To assess the association of race/ethnicity and education status on time to intervention and the total number of interventions in pediatric patients with microtia undergoing hearing intervention and external ear reconstruction. METHODS:A retrospective chart review was performed in pediatric patients diagnosed with congenital ear deformities evaluated by an otolaryngologist or audiologist from January 1, 2013 to December 1, 2021 at a large surgical institution. Variables analyzed included demographics, patient conditions, time to surgery, and number of surgeries. Statistical analysis included analysis of variance, chi-squared tests, and multivariate regression. RESULTS:Disparities were identified in reconstructive microtia repair, with non-White patients having an increased number of external ear reconstructive surgeries (p = 0.004), with Black patients average 2 external ear reconstructive surgeries, Hispanic patients 1.74 surgeries, while White patients averaged 0.812 surgeries. All non-White patients also demonstrated increased total number of surgeries (1.94 Asian, 2.57 Black, 2.11 Hispanic, 3.29 Other/Unknown, vs 1.23 White, p = 0.007) and total number of interventions (2.17 Asian, 2.71 Black, 2.37 Hispanic 3.43 Other/Unknown, vs 1.56 White, p = 0.02) as compared to White patients. In multivariate regression analysis, race was a significant factor influencing the number of reconstructive and overall surgeries, while the presence of aural atresia was the strongest predictor for requiring additional hearing surgery. CONCLUSION/CONCLUSIONS:An increased number of interventions and surgeries were seen amongst non-White patients with microtia. Further investigation is warranted to understand the socioeconomic factors associated with pediatric microtia surgery.

We leverage a clinical trial (NCT04080804) that compared neoadjuvant anti-PD-1, anti-PD-1+CTLA-4, and anti-PD-1+LAG-3 therapies in head and neck squamous cell carcinoma patients. Combination therapies promote higher pathologic response rates versus monotherapy, and major pathologic response is associated with better survival. To address whether successful immune checkpoint inhibitor (ICI) regimens act through similar or distinct pathways, we robustly and longitudinally characterize transcriptional and proteomic dynamics of CD8⁺ tumor-infiltrating lymphocytes (TILs) in a clonal manner. Anti-PD-1+LAG-3 reprograms CD8⁺ TIL with type-I interferon response and exhaustion gene programs into effector memory and resident memory (T_EM/T_RM). In contrast, anti-PD-1+CTLA-4 activates and expands pre-existing T_EM/T_RM CD8⁺ TIL, but does not rejuvenate exhausted phenotypes into T effector cells. Anti-PD-1+LAG-3, but not anti-PD-1+CTLA-4, induces widespread TCR sharing among the different transcriptional states, as well as increased TCR diversity in responding patients. Our data suggest doublet regimen-specific transcriptional and clonal dynamics of tumor-reactive CD8⁺ T cells.

OBJECTIVES/HYPOTHESIS/OBJECTIVE:This study investigated the effects of the "crack-sob" onset-a distinctive vocal technique combining a sob gesture with an intentional pitch break-on vocal fold function during high-intensity singing. We hypothesized that this onset would either decrease glottal adduction and increase vocal fold vibration stability or alternatively, show no measurable effects while still providing perceived benefits to singers. STUDY DESIGN/METHODS:Prospective observational cohort study. METHODS:Twenty professional musical theatre singers (10 male, 10 female) performed high-intensity sustained notes with and without the crack-sob onset using both a control phrase and self-selected repertoire. Electroglottography measured contact quotient (CQ) and its relative standard deviation (relSDCQ). Acoustic analysis quantified smoothed cepstral peak prominence (CPPS), harmonics-to-noise ratio (HNR), and vocal intensity (dB SPL). Linear mixed effects modeling was used to analyze the effects of the crack-sob maneuver, with sex and vocal phrase as covariates. RESULTS:The crack-sob onset showed no significant effects on any measured parameters. CQ remained consistent at 66% regardless of onset type. No significant changes were observed in CPPS, dB SPL, relSDCQ, or HNR when using the crack-sob onset, with all effect sizes below 0.1. Significant differences were found between control and self-selected phrases, with the control phrase showing higher CPPS (+2.6 dB), intensity (+2.7 dB SPL), and HNR (+4.3). CONCLUSIONS:The crack-sob onset does not significantly alter objective measures of vocal fold adduction or vibratory stability during sustained high-intensity phonation in trained singers. The technique's reported benefits may be primarily perceptual rather than physiological, suggesting its value as a pedagogical tool for managing singer effort without compromising vocal function.

OBJECTIVE:Infantile subglottic hemangioma (SGH) poses a risk of airway compromise if untreated. Traditionally, operative endoscopy (OH) diagnoses SGH, but since the discovery of beta-blockers' efficacy in treating infantile hemangiomas (IHs) in 2008, and advances in endoscopic technology, nonoperative methods have emerged. This review identifies endoscopic practices for diagnosing and monitoring infantile SGH during the oral beta-blocker treatment era. DATA SOURCES/METHODS:A comprehensive literature search in October 2022 and August 2023 covered PubMed, Embase, Cochrane Library, SCOPUS, and Web of Science. REVIEW METHODS/METHODS:The search was limited to English-language studies published since 2008, considering this when propranolol was demonstrated as an effective treatment option for IH. The articles were screened for relevance based on predefined inclusion and exclusion criteria. RESULTS:After inclusion and exclusion criteria, sixty final studies were identified, describing 240 cases of infantile SGH. Most children were diagnosed using OE alone (73.3%; n = 176/240), 23.3% (n = 56/240) using office-based laryngoscopy procedures (OBPs) followed by OE, 3.3% using OBP alone (n = 8/240). There were no reported diagnostic endoscopy-related complications. Twenty-nine studies described using endoscopy plus diagnostic imaging to either confirm an SGH lesion, characterize the extent of disease spread, or rule out other causes of presenting symptoms. The proportion of infants diagnosed with OE alone decreased from 2008 to 2023. CONCLUSION/CONCLUSIONS:Operative endoscopy remains the SGH diagnostic standard, but OBP adoption is increasing. Further research is needed to determine the optimal SGH diagnosis and management approach. LEVEL OF EVIDENCE/METHODS:NA Laryngoscope, 2024.

OBJECTIVES/OBJECTIVE:Real-time monitoring of cochlear function to predict the loss of residual hearing after cochlear implantation is now possible. Current approaches monitor the cochlear microphonic (CM) during implantation from the electrode at the tip of the implant. A drop in CM response of >30% is associated with poorer hearing outcomes. However, there is prior evidence that CM amplitude can fluctuate in a manner unrelated to hearing trauma, leading to false positives. By monitoring another cochlear response, the auditory nerve neurophonic (ANN), a differentiation between CM drops that result in reduced cochlear output from false positives may be possible. The hypothesis tested in the present work was that ANN/CM ratios measured during a CM drop will increase during drops not associated with postoperative hearing loss. DESIGN/METHODS:Twenty-eight adult participants with known CM drops during implantation were taken from a larger data set. This contains adult cochlear implant candidates scheduled to receive a Cochlear Nucleus cochlear implant with either the slim-straight or slim-modiolar electrode array with preoperative audiometric low-frequency average thresholds of ≤80 dB HL at 500, 750, and 1000 Hz in the ear to be implanted. Patients were recruited from eight international implant sites. Pure-tone audiometry was measured postoperatively and 4 to 6 weeks after implantation. Electrocochleography was measured during and immediately after the implantation of the array in response to a 500-Hz, 6-msec pure-tone pip at 110 dB HL. RESULTS:The ANN/CM ratio rose during CM drops in 19 of these patients and decreased in 9. At the follow-up timepoint, patients with a decreasing ANN/CM ratio had a median hearing loss of 29.0 dB, significantly worse than the group with increasing ratio at 13.3 dB ( p = 0.004). Considering only the change in ANN amplitude during a CM drop led to smaller groups (ANN drop during CM drop N = 17, ANN increasing during CM drop N = 6) due to 5 patients having undetectable ANN during the CM drop. Using the ANN alone also led to as poorer prediction of hearing preservation, with median hearing preservation in the ANN increasing group of 12.9 dB, significantly better than the ANN decreasing group of 25 dB ( p = 0.02). The group with a decreasing ANN/CM ratio had maximum CM amplitude immediately after insertion lower than the maximum amplitude reached during insertion (mean maximum postinsertion amplitude of 98% of during-insertion amplitude). In comparison, the ANN/CM ratio increasing group tended to have a larger CM amplitude immediately after insertion (mean maximum CM amplitude postinsertion of 164% of the maximum during-insertion amplitude). CONCLUSIONS:These data show that the ANN/CM ratio is a measure that can differentiate between patients with CM drops that lead to a loss of residual hearing and those that do not. The ANN/CM ratio is easily measured and responds rapidly during a CM drop, showing clinical promise for improving current and developing approaches to intraoperative monitoring.

Motor neurons have highly diverse anatomical, functional and molecular features, and differ significantly in their susceptibility in disease. Extraocular motor neurons, residing in the oculomotor, trochlear and abducens cranial nuclei (nIII, nIV and nVI), control eye movements. Recent work has begun to clarify the developmental mechanisms by which functional diversity among extraocular motor neurons arises. However, we know little about the role and consequences of extraocular motor neuron diversity in eye movement control. Here, we highlight recent work investigating the anatomical, functional and molecular features of extraocular motor neurons. Further, we frame hypotheses where studying ocular motor circuits in the larval zebrafish is poised to illuminate the consequences of motor neuron diversity for behavior.