The central oxytocinergic system of the prairie vole.

Oxytocin (OXT) is a peptide hormone and a neuropeptide that regulates various peripheral physiological processes and modulates behavioral responses in the central nervous system. While the humoral release occurs from the axons arriving at the median eminence, the neuropeptide is also released from oxytocinergic cell axons in various brain structures that contain its receptor, and from their dendrites in hypothalamic nuclei and potentially into the cerebrospinal fluid (CSF). Understanding oxytocin's complex functions requires the knowledge on patterns of oxytocinergic projections in relationship to its receptor (OXTR). This study provides the first comprehensive examination of the oxytocinergic system in the prairie vole (Microtus ochrogaster), an animal exhibiting social behaviors that mirror human social behaviors linked to oxytocinergic functioning. Using light and electron microscopy, we characterized the neuroanatomy of the oxytocinergic system in this species. OXT+ cell bodies were found primarily in the hypothalamus, and axons were densest in subcortical regions. Examination of the OXT+ fibers and their relationship to oxytocin receptor transcripts (Oxtr) revealed that except for some subcortical structures, the presence of axons was not correlated with the amount of Oxtr across the brain. Of particular interest, the cerebral cortex that had high expression of Oxtr transcripts contained little to no fibers. Electron microscopy is used to quantify dense cored vesicles (DCV) in OXT+ axons and to identify potential axonal release sites. The ependymal cells that line the ventricles were frequently permissive of DCV-containing OXT+ dendrites reaching the third ventricle. Our results highlight a mechanism in which oxytocin is released directly into the ventricles and circulates throughout the ventricular system, may serve as the primary source for oxytocin that binds to OXTR in the cerebral cortex.

Severe PTSD is marked by reduced oxytocin and elevated vasopressin.

Neuroendocrine analyses of posttraumatic stress disorder (PTSD) have generally focused on hypothalamic-pituitary-adrenal (HPA) axis alterations. In the present analyses, we examine two additional neuroendocrine factors that have been previously implicated in biological stress responses: oxytocin (OT) and arginine vasopressin (AVP). Here we examined basal neuropeptide status in military veterans clinically diagnosed with PTSD (n = 29) and in two non-traumatized comparison groups with previous stress exposure (n = 11 SWAT trainees and n = 21 ultramarathon runners). PTSD patients showed low levels of plasma OT and high levels of AVP. The ratio of AVP/OT robustly related to PTSD status, and emerged as a statistically plausible mediator of relationships between the number of personal traumatic experiences and subsequent PTSD symptom burden. Over the course of behavioral therapy for PTSD, measures of OT showed a significant but modest normalization. Plasma cortisol levels were not statistically different among the three groups. This study suggests that AVP/OT ratios may represent a neuroendocrine predictor of severe PTSD, as well as a potential treatment response biomarker.

Maternal oxytocin treatment at birth increases epigenetic age in male offspring.

Exogenous oxytocin (OT) is widely used to induce or augment labor with little understanding of the impact on offspring development. In rodent models, including the prairie vole (Microtus ochrogaster), it has been shown that oxytocin administered to mothers can affect the nervous system of the offspring with long lasting behavioral effects especially on sociality. Here, we examined the hypothesis that perinatal oxytocin exposure could have epigenetic and transcriptomic consequences. Prairie voles were exposed to exogenous oxytocin, through injections given to the mother just prior to birth, and were studied at the time of weaning. The outcome of this study revealed increased epigenetic age in oxytocin-exposed animals compared to the saline-exposed group. Oxytocin exposure led to 900 differentially methylated CpG sites (annotated to 589 genes), and 2 CpG sites (2 genes) remained significantly different after correction for multiple comparisons. Differentially methylated CpG sites were enriched in genes known to be involved in regulation of gene expression and neurodevelopment. Using RNA-sequencing we also found 217 nominally differentially expressed genes (p<0.05) in nucleus accumbens, a brain region involved in reward circuitry and social behavior; after corrections for multiple comparisons 6 genes remained significantly differentially expressed. Finally, we found that maternal oxytocin administration led to widespread alternative splicing in the nucleus accumbens. These results indicate that oxytocin exposure during birth may have long lasting epigenetic consequences. A need for further investigation of how oxytocin administration impacts development and behavior throughout the lifespan is supported by these outcomes.

Looking Across the Drape: A Novel Quality Improvement Approach to Understanding Surgeon and Anesthesiologist Burnout.

OBJECTIVE: To identify well-being threats for surgeons and anesthesiologists and develop interventions using the Quality of Life Improvement (QOLI) approach. BACKGROUND: Developing feasible perioperative well-being interventions requires identifying shared and specialty-specific well-being needs. The QOLI framework integrates human-centered design, implementation science, and quality improvement to address well-being needs. METHODS: Anesthesia and surgery faculty in eight perioperative departments at an academic medical center completed cross-sectional surveys containing validated measures of well-being and workplace satisfaction, and open-ended questions about professional motivations, pain points, strategies for improvement, and well-being priorities. Using template analysis, we analyzed open-ended survey data and presented resulting themes at a joint-specialty town hall for live-voting to identify well-being priorities. RESULTS: 104 perioperative faculty completed the survey. Across specialties, higher MHC-SF scores (representative of individual global well-being) were associated with higher satisfaction with workplace control, values, decision latitude, and social support. Anesthesiologists reported lower satisfaction and control than surgeons across multiple domains. Template analysis yielded five areas for intervention: (1) Work culture, (2) Work environment/resources, (3) Sources of fulfillment, (4) Work/life harmony, (5) Financial compensation. Surgeons and anesthesiologists both prioritized high-quality patient care but differed in their other top priorities. The most frequently cited well-being threats for surgeons were OR inefficiencies/delays and excessive workload, while anesthesiologists cited understaffing and unpredictable work hours. CONCLUSIONS: Surgeons and anesthesiologists share many needs and priorities, with pain points that are often negatively synergistic. Applying the QOLI approach across specialties allows for well-being interventions that honor complexity and promote the development of feasible solutions.

Mindfulness Based Interventions for Surgeons: A Scoping Review.

OBJECTIVE: To review the evidence on mindfulness-based interventions (MBIs) for surgeons. BACKGROUND: Healthcare professionals have alarmingly high rates of burnout, yet little is known about psychological factors that support resilience. MBIs, which involve codified training in specific skills such as self-awareness, emotional regulation, and perspective-taking, have shown benefit to professionals in high stress environments, but have had limited implementation in the healthcare workplace and in surgery. To our knowledge, there has not been a scoping review of MBIs in surgery to date. METHODS: We conducted a scoping review of the evidence for the feasibility and effectiveness of MBIs for surgeons, including evidence on interventions that explicitly train mindfulness, which spans multiple cohorts and settings, utilizing different methodologies and outcome measures. RESULTS: This scoping review yielded 24 studies, including two mixed method/qualitative studies, nine randomized control trials, three non-randomized interventional studies, and eight single-arm interventional studies. CONCLUSIONS: We find that MBIs in surgery 1) are feasible in surgical contexts, with implementation science providing insights on sustainability; 2) increase mindfulness, 3) improve well-being in terms of burnout and both psychological and neurophysiological measures of stress, and 4) enhance performance as measured in executive function, surgical skills, and communication skills. These conclusions are supported by psychometric measures, observations of technical skills, and neurophysiological evidence. Future directions include studying MBIs in larger and more diverse populations, and iteratively tailoring mindfulness-based interventions to other healthcare contexts.

Neurophysin I is an analytically robust surrogate biomarker for oxytocin.

Oxytocin is a pleiotropic neuropeptide that plays roles in biological processes ranging from birth, lactation, and social bonding to immune function, cardiovascular repair, and regulation of appetite. Although measurements of endogenous oxytocin concentrations have been performed for more than 50 years, the ability to measure oxytocin accurately poses notable challenges. One potential solution for overcoming these challenges involves measurement of oxytocin's carrier molecule - neurophysin I (NP-1) - as a surrogate biomarker. NP-1 is secreted in equimolar concentrations with oxytocin but has a longer half-life, circulates in higher concentrations, and can be measured using a sandwich immunoassay. We report experiments that 1) analytically validate a commercially available NP-1 sandwich immunoassay for use with human plasma and urine samples, 2) confirm the specificity of this assay, based on detection of NP-1 in plasma from wild-type but not oxytocin knockout mice, 3) demonstrate that NP-1 concentrations are markedly elevated in late pregnancy, consistent with studies showing substantial increases in plasma oxytocin throughout gestation, and 4) establish strong correlation between NP-1 and plasma oxytocin concentrations when oxytocin is measured in extracted (but not non-extracted) plasma. The NP-1 assay used in this study has strong analytical properties, does not require time-intensive extraction protocols, and the assay itself can be completed in < 2 h (compared to 16-24 h for a competitive oxytocin immunoassay). Our findings suggest that much like copeptin has become a useful surrogate biomarker in studies of vasopressin, measurements of NP-1 have similar potential to advance oxytocin research.

Feasibility Study to Compare Oxytocin Function Between Body Mass Index Groups at Term Labor Induction.

OBJECTIVE: To determine the feasibility of a protocol to examine the association between oxytocin system function and birth outcomes in women with and without obesity before induction of labor. DESIGN: Prospective descriptive. SETTING: Academic medical center in the U.S. Midwest. PARTICIPANTS: Pregnant women scheduled for induction of labor at 40 weeks of gestation or greater (n = 15 normal weight; n = 15 obese). METHODS: We collected blood samples and abstracted data by chart review. We used percentages to examine adherence to protocol. We used t tests and chi-square tests to describe differences in sample characteristics, oxytocin system function variables, and birth outcomes between the body mass index groups. RESULTS: The recruitment rate was 85.7%, protocol adherence was 97.1%, and questionnaire completion was 80.0%. Mean plasma oxytocin concentration was higher in the obese group (M = 2774.4 pg/ml, SD = 797.4) than in the normal weight group (M = 2193.5 pg/ml, SD = 469.8). Oxytocin receptor DNA percentage methylation (CpG -934) was higher in the obese group than in the normal weight group. CONCLUSION: Our protocol was feasible and can serve as a foundation for estimating sample sizes in forthcoming studies investigating the diversity in oxytocin system measurements and childbirth outcomes among pregnant women in different body mass index categories.

Investigating influential factors and mechanisms of surgical resident well-being using social network analysis.

BACKGROUND: Burnout and depression in General Surgery residents affect patient care and drive attrition. Few impactful interventions exist, in part because little is known about influential drivers and mechanistic relationships. METHODS: Residents from 16 general surgery programs completed published well-being scales in January 2021. Social network analysis demonstrated influential relationships between factors, and path analysis revealed drivers of burnout and depression. RESULTS: 300 residents completed the survey (34% response rate). Workplace demand and mindfulness influenced depressive symptoms and emotional exhaustion, mediated by perceived stress. Mindfulness increased personal accomplishment, mediated by psychological well-being (p â€‹< â€‹0.05 for all results). All mediated effects were greater than direct effects. CONCLUSIONS: This study yielded a quantitative conceptual model of mechanistic relationships affecting well-being in surgical residency, identifying stress and psychological well-being (measuring sense of purpose) as central mediators, and triangulating workplace demand and mindfulness as potentially high-yield interventional targets for reducing burnout and depression in surgical residency.

Intramuscular Administration of Tranexamic Acid in a Large Swine Model of Hemorrhage with Hyperfibrinolysis.

BACKGROUND: Traumatic injury with subsequent hemorrhage is one of the leading causes of mortality among military personnel and civilians alike. Post traumatic hemorrhage accounts for 40-50% of deaths in severe trauma patients occurring secondary to direct vessel injury or the development of trauma induced coagulopathy (TIC). Hyperfibrinolysis plays a major role in TIC and its presence increases a patient's risk of mortality. Early therapeutic intervention with intravenous (IV) tranexamic acid (TXA) prevents development of hyperfibrinolysis and subsequent TIC leading to decreased mortality. However, obtaining IV access in an austere environment can be challenging. In this study, we evaluated the efficacy of intramuscular (IM) versus IV TXA at preventing hyperfibrinolysis in a hemorrhaged swine. METHODS: Yorkshire cross swine were randomized on the day of study to receive IM or IV TXA or no treatment. Swine were sedated, intubated, and determined to be hemodynamically stable prior to experimentation. Controlled hemorrhaged was induced by the removal of 30% total blood volume. After hemorrhage, swine were treated with 1000 mg of IM or IV TXA. Control animals received no treatment. Thirty minutes post TXA treatment, fibrinolysis was induced with a 50 mg bolus of tissue plasminogen activator (tPA). Blood samples were collected to evaluate blood TXA concentrations, blood gases, blood chemistry, and fibrinolysis. RESULTS: Blood TXA concentrations were significantly different between administration routes at the early timepoints, but were equivalent by 20 minutes after injection, remaining consistently elevated for up to three hours post administration. Induction of fibrinolysis resulted in 87.18 ± 4.63% lysis in control animals, compared to swine treated with IM TXA 1.96 ± 2.66 % and 1.5 ± 0.42% lysis in the IV TXA group. CONCLUSION: In the large swine model of hemorrhage with hyperfibrinolysis, IM TXA is bioequivalent and equally efficacious in preventing hyperfibrinolysis as IV TXA administration.

Feasibility of Stress Research in Premature Infant-Maternal Dyads During and After Neonatal Intensive Care Unit Hospitalization.

BACKGROUND: Stress from preterm infant admission to the neonatal intensive care unit (NICU) is associated with infant and maternal physiologic changes, including endocrine and epigenetic alterations. Little is known about the mechanisms connecting NICU stress to biologic changes, and whether preterm infant and maternal stress are reciprocal. As a preliminary step, feasibility and acceptability of measuring indicators of stress are required. PURPOSE: This study evaluated the feasibility and acceptability of research examining perceptions and biologic markers of stress in premature infant-maternal dyads during and after NICU hospitalization. METHODS: We evaluated study feasibility using a longitudinal descriptive design. Acceptability was measured via a maternal questionnaire. Exploratory data regarding hospitalization, perceptions of stress, social support and social determinants of health, and biologic markers of stress were collected during the first week of life and again 3 months after NICU. RESULTS: Forty-eight mothers were eligible for the study, 36 mothers were approached, 20 mothers consented to participate, and 14 mothers completed data collection. Mothers reported high levels of study acceptability despite also voicing concern about the sharing of genetic data. Exploration of DNA methylation of SLC6A4 in preterm infants was significant for a strong correlation with perception of total chronic stress. IMPLICATIONS FOR PRACTICE AND RESEARCH: Clinical practice at the bedside in the NICU should include standardized screening for and early interventions to minimize stress. Complex research of stress is feasible and acceptable. Future research should focus on linking early life stress with epigenetic alterations and evaluation of the dyad for reciprocity.

Transcriptional diversity of the oxytocin receptor in prairie voles: mechanistic implications for behavioral neuroscience and maternal physiology.

The neurohormone oxytocin regulates many aspects of physiology primarily by binding to its receptor, the oxytocin receptor. The oxytocin receptor gene (Oxtr) has been shown to have alternative transcripts in the mouse brain which may each have different biological functions or be used in specific contexts. A popular animal model for studying oxytocin-dependent social behaviors is the prairie vole, a biparental and monogamous rodent. Alternative transcriptional capacity of Oxtr in prairie voles is unknown. We used 5' rapid amplification of cDNA ends to identify alternative Oxtr transcription start sites in prairie vole brain tissue and uterine tissue. We then validated expression of specific transcripts in fetal brains and assessed the impact of exogenous oxytocin administration in utero on offspring brain development. We identified seven distinct Oxtr transcripts, all of which are present in both brain and uterine tissue. We then demonstrated that maternal oxytocin administration alters expression of a specific subset of Oxtr transcripts and that these different transcripts are under unique epigenetic regulation, such that in the perinatal period only one of the alternative transcripts is associated with DNA methylation in the Oxtr promoter. These data establish the existence of multiple Oxtr transcripts in prairie vole brain and uterine tissue and implicate oxytocin in the regulation of alternative transcript expression. These data have significant implications for our understanding of null mutant models in both mice and voles and translation in human birth and behavior.

Sex and hormonal status influence the anxiolytic-like effect of oxytocin in mice.

Anxiety and depression are highly prevalent psychiatric disorders, affecting approximately 18% of the United States population. Evidence indicates that central oxytocin mediates social cognition, social bonding, and social anxiety. Although it is well-established that oxytocin ameliorates social deficits, less is known about the therapeutic effects of oxytocin in non-social contexts. We hypothesized that positive effects of oxytocin in social contexts are attributable to intrinsic effects of oxytocin on neural systems that are related to emotion regulation. The present study investigated the effect of intracerebroventricular (ICV) oxytocin administration (i.e., central action) on anxiety- and depression-like behavior in C57Bl/6J mice using non-social tests. Male and female mice received an ICV infusion of vehicle or oxytocin (100, 200, or 500 ng), then were tested in the elevated zero maze (for anxiety-like behavior) and the tail suspension test (for depression-like behavior). Oxytocin dose-dependently increased open zone occupancy and entries in the elevated zero maze and reduced immobility duration in the tail suspension test in both sexes. Oxytocin decreased anxiety and depression-like behavior in male and female mice. The observed effect of oxytocin on anxiolytic-like behavior appeared to be driven by the males. Given the smaller anxiolytic-like effect of oxytocin in the female mice and the established interaction between oxytocin and reproductive hormones (estrogen and progesterone), we also explored whether oxytocin sensitivity in females varies across estrous cycle phases and in ovariectomized females that were or were not supplemented with estrogen or progesterone. Oxytocin reduced anxiety-like behavior in female mice in proestrus/estrus, ovariectomized females (supplemented or not with estrogen or progesterone), but not females in metestrus/diestrus. Additionally, oxytocin reduced depression-like behavior in all groups tested with slight differences across the various hormonal statuses. These results suggest that the effect of oxytocin in depression- and anxiety-like behavior in mice can be influenced by sex and hormonal status.

Enhanced Stress Resilience Training for UK Surgical Trainees; Effect and Evolution Evaluated.

INTRODUCTION: Core Surgical Training (CST) programs are associated with high burnout. This study aimed to assess the influence of Enhanced Stress Resilience Training (ESRT) over a 2-year period in a single UK Statutory Education Body. METHOD: CSTs participated in 5-weeks of formal ESRT to address work stressors. The primary outcome measure was career progression related to curriculum metrics and National Training Number (NTN) appointment. Secondary measures related to burnout using validated psychological inventories. RESULTS: Of 42 CSTs, 13 engaged fully with ESRT (31.0%; male 8, female 5, median age 28 year.), 11 engaged partially, and 18 did not. ESRT engagement was associated with better NTN appointment (ESRT 8/13 (61.5%) vs. not 1/18 (5.6%), p = 0.025), less burnout [aMBI; mean 5.14 (SD ± 2.35) vs. 3.14 (±2.25), F 6.637, p = 0.002, ηp2=0.167], less stress [PSS-10; 19.22 (±5.91) vs. 15.79 (±5.47), F 8.740, p < 0.001, ηp2=0.200], but more mindfulness [CAMS-R; 19.22 (±5.91) vs. 20.57 (±2.93), F 3.201, p = 0.047, ηp2=0.084]. On multivariable analysis, Improving Surgical Training (run-through CST) program (OR 5.2 (95% CI 1.42-28.41, p = 0.022), MRCS pass (OR 17.128 (95% CI 1.48-197.11, p = 0.023) and ESRT engagement (OR 13.249, 95% CI 2.08-84.58, p = 0.006) were independently associated with NTN success. DISCUSSION: ESRT was associated with less stress and burnout, better mindfulness, and most importantly 13-fold better career progression.

Flourishing and the Prioritization of Workplace Elements in General Surgery Residents.

INTRODUCTION: To explore and begin to operationalize workplace elements that influence general surgery (GS) resident wellbeing. Tailoring workplace wellbeing interventions is critical to their success. Occupational science has revealed that a person-centered approach to identifying positive and negative workplace influences can inform tailoring while accounting for individual differences. To our knowledge, this approach has not been applied to the surgical training environment. METHODS: A national sample of GS residents from 16 Accreditation Council for Graduate Medical Education training programs ranked the importance of workplace elements via an anonymous survey. Latent profile analysis was performed to identify shared patterns of workplace element prioritization and their relation to levels of flourishing, a measure of global wellbeing. RESULTS: GS trainee respondents (n = 300, 34% response rate - average for studies with this sample population) expressed a hierarchy of workplace element importance which differed by gender and race. "Skills to manage stress" and "a team you feel a part of" were prioritized higher by non-males than males. Residents of color and residents underrepresented in medicine, respectively, prioritized "recognition of work/effort" and "skills to manage stress" more than White and overrepresented in medicine residents. Flourishing prevalence varied by 40% with small differences in the specific profile of workplace element prioritization. CONCLUSIONS: Differences in prioritization of workplace elements reveal subtle but important differences that may guide the design of wellbeing interventions for different populations within surgery.

Close encounters with oxytocin.

The purpose of this narrative review is to use a personal perspective to describe unanticipated and pivotal findings that drew the author into the study oxytocin. Oxytocin was originally described as a "female reproductive hormone." However, supporting reproduction is only one of a myriad of functions now attributed to oxytocin. Oxytocin promotes survival and resilience in both sexes and across the lifespan, especially in the context of stress or trauma and helps to explain the health benefits of relationships. Oxytocin works in the context of individual histories and in conjunction with other molecules, as well as the autonomic nervous system and immune factors. The chemical properties of oxytocin make it biologically active, but difficult to measure. As a deeper understanding of the biology of oxytocin is emerging, we may use knowledge of the properties of oxytocin to uncover adaptive strategies that protect and heal in the face of stress and adversity in both males and females.

Father's care uniquely influences male neurodevelopment.

Mammalian infants depend on parental care for survival, with numerous consequences for their behavioral development. We investigated the epigenetic and neurodevelopmental mechanisms mediating the impact of early biparental care on development of alloparenting behavior, or caring for offspring that are not one's own. We find that receiving high parental care early in life leads to slower epigenetic aging of both sexes and widespread male-specific differential expression of genes related to synaptic transmission and autism in the nucleus accumbens. Examination of parental care composition indicates that high-care fathers promote a male-specific increase in excitatory synapses and increases in pup retrieval behavior as juveniles. Interestingly, females raised by high-care fathers have the opposite behavioral response and display fewer pup retrievals. These results support the concept that neurodevelopmental trajectories are programmed by different features of early-life parental care and reveal that male neurodevelopmental processes are uniquely sensitive to care by fathers.

The relationship between endogenous oxytocin and vasopressin levels and the Prader-Willi syndrome behaviour phenotype.

Background: Oxytocin and vasopressin systems are altered in Prader Willi syndrome (PWS). However, investigations into endogenous oxytocin and vasopressin levels as well as clinical trials evaluating the effect of exogenous oxytocin on PWS symptoms have had mixed results. It is also unknown whether endogenous oxytocin and vasopressin levels are associated with certain PWS behaviours. Method: We compared plasma oxytocin and vasopressin and saliva oxytocin levels in 30 adolescents and adults with PWS to 30 typically developing age-matched controls. We also compared neuropeptide levels between gender and genetic subtypes within the PWS cohort and examined the relationship between neuropeptide levels and PWS behaviours. Results: While we did not measure a group difference in plasma or saliva oxytocin levels, plasma vasopressin was significantly lower in individuals with PWS compared to controls. Within the PWS cohort, saliva oxytocin levels were higher in females compared to males and individuals with the mUPD compared to the deletion genetic subtype. We also found the neuropeptides correlated with different PWS behaviours for males and females and for genetic subtypes. For the deletion group, higher plasma and saliva oxytocin levels were related to fewer behaviour problems. For the mUPD group, higher plasma vasopressin levels were related to more behaviour problems. Conclusion: These findings support existing evidence of a vasopressin system defect in PWS and for the first time identify potential differences in the oxytocin and vasopressin systems across PWS genetic subtypes.

A Simple and Flexible Infusion Platform for Automated Native Mass Spectrometry Analysis.

High throughput native mass spectrometry analysis of proteins and protein complexes has been enabled by recent development of infusion and liquid chromatography (LC) systems, which often include complete LC pumps without fully utilizing their gradient flows. We demonstrated a lower-cost infusion cart for native mass spectrometry applications using a single isocratic solvent pump that can operate at both nano- and high-flow configurations (0.05-150 µL/min) for both infusion and online buffer exchange experiments. The platform is controlled via open-source software and can potentially be expanded for customized experimental designs, offering a lower cost alternative to laboratories with limited budgets and/or needs in student training.