Uncovering moderators of pain perception by women with endometriosis from Latin America and Spain: the roles of sociodemographics, racial self-identity, and pain catastrophizing.

ABSTRACT: A cross-sectional multinational collaborative study on women with endometriosis from Latin America and Spain uncovered high levels of painful symptomatology and high pain catastrophizing scores. Associations between pain perception/catastrophizing and race/ethnicity have been documented. This study was conducted to uncover factors moderating pelvic pain severity, including socioeconomic variables, self-identified race, and pain catastrophizing in women with endometriosis from Latin America and Spain, a population encompassing diverse racial and sociocultural contexts. Self-reported data on demographics, clinical history, Ob-Gyn history, pelvic pain intensity, and pain catastrophizing were collected with the Spanish World Endometriosis Research Foundation (WERF) Endometriosis Phenome Project (EPhect) Clinical Questionnaire (ECQ). Multiple logistic regression was conducted to analyze effects of self-identified race, demographic clusters (defined as countries with similar racial population distribution), socioeconomic factors, and pain catastrophizing on reporting severe vs moderate-mild levels of dysmenorrhea, dyspareunia, and pelvic pain. Self-identified race did not affect the likelihood of reporting severe pelvic pain; however, there were significant differences in reporting severe dysmenorrhea at worst among demographic clusters. Older age was associated with severe dyspareunia at worst and recent pelvic pain. Pain catastrophizing score was highly predictive of reporting most types of severe pelvic pain, regardless of race and demographic cluster. These results negate a role of racial categories as moderator of pain in women from Latin America and Spain and support integration of pain catastrophizing assessments and psychological interventions into the pain management plan to enhance therapeutic outcomes and QoL for patients with endometriosis.

Efficacy of an environmental enrichment intervention for endometriosis: a pilot study.

Introduction: We have previously shown that Environmental Enrichment (EE), a multi-modal psychosocial intervention consisting of increased social interaction, novelty, and open spaces, improved disease presentation, anxiety, and immune-related disturbances in the rat model of endometriosis. However, there is a knowledge gap regarding the effects of EE interventions in patients with this painful, inflammatory chronic disease. Aim: To adapt and test the efficacy of an EE intervention on pelvic pain, mental health, perceived stress, quality of life, and systemic inflammation in endometriosis patients through a randomized clinical trial (RCT). Materials and methods: A multidisciplinary team with expertise in physiology, neuroscience, psychology, and women's health adapted and implemented a two-arm RCT comparing an EE intervention with a wait-list control group. Six EE modules administered on alternate weeks were provided to patients in the intervention (N = 29); controls received education only. Survey data and biospecimens were collected at baseline, end-of-study, and 3-months post-intervention to assess pain (Brief Pain Inventory, BPI), endometriosis-related quality of life-QoL (Endometriosis Health Profile-30, EHP30), anxiety (Generalized Anxiety Disorder 7, GAD7), depression (Patient Health Questionnaire for Depression 8, PHQ8), pain catastrophizing (Pain Catastrophizing Score, PCS), stress (Perceived Stress Scale-14, PSS14), and saliva cortisol levels (AM, PM). Results: Compared to the wait-list controls, participants in the EE intervention showed significantly decreased GAD-7 scores at the end of the intervention and 3-month follow-up. Depression, perceived stress, and QoL improved at the 3-month follow-up compared to baseline. While pain levels did not improve, they significantly correlated with anxiety, depression, QoL and pain catastrophizing scores. Conclusion: This pilot RCT demonstrated significant improvements in anxiety and depressive symptoms, QoL, and perceived stress, supporting enriched environments as an integrative psychosocial intervention to be used as adjuvant to the standard of care for endometriosis pain.

Comparative analysis of all-terrain vehicles, motorcycle and automobile-related trauma in a rural border community of the USA.

INTRODUCTION: There is widespread use of all-terrain vehicles (ATVs) in the USA for both work-related and recreational activities. In this study, we aimed to determine the difference in injury severity, Glasgow Coma scales and length of stay between ATV-related injuries and injuries sustained from motorcycles (MOTOs) and automobiles (AUTOs). METHODS: We retrospectively analysed ATV, MOTO and AUTO injuries from a Level 2 Trauma Center between 01 January 2015 and 31 August 2020. Proportional odds regression analyses, as well as multivariable regression models, were used to analyse the data. RESULTS: There were significantly more male and paediatric patients that suffered ATV-related injuries compared with MOTO or AUTO injuries. Victims of ATV-related injuries were also more likely to have open fractures. Paediatric patients were less likely to sustain an injury from either AUTO or MOTO accidents compared with ATV accidents. Patients with no drug use during injury and those who used protective equipment such as seat belts and child seats were significantly associated with lower Injury Severity Scores and higher Glasgow Coma Scale scores, indicating less severe injuries. DISCUSSION: Paediatric patients are very likely to suffer sequela and long-term disability due to the severity of ATV-related injuries. Public awareness campaigns to educate our population, especially our youth, about the danger of ATV use are highly needed.

Scoping review on environmental enrichment: Are critical periods and sex differences adequately studied?

BACKGROUND: Decades of research have shown the robust behavioral, structural, and molecular effects of environmental enrichment (EE) which predominantly improves neuropathological conditions. However, systematic examination of age and sex influences in response to EE is limited. OBJECTIVE: Examine the use of EE and evaluate where sex differences (or similarities) are described and whether critical developmental periods are addressed. A critical examination of review articles about EE will establish a framework for the context of the findings of EE-induced effects, improve the impact of future EE studies and improve translatability. ELIGIBILITY CRITERIA: Narrative, systematic reviews (not original reports) and meta-analyses of any animal species published during 2011 to 2021. Clinical and farming studies were excluded. SOURCES OF EVIDENCE: Indexed review articles in Pubmed and Psychinfo. RESULTS: Most studies examine EE during adulthood such as following an injury or following repeated addictive drug exposure. However, in various genetic models of disease states, little attention is paid to effects of EE at different ages. Only some reviews acknowledge that sex differences exist even when the disease state under study is known to be sexually dimorphic. Identified issues include lack of systematic reporting; status of the "control group" (i.e., isolation or pair housing); the use and reporting of proper statistical analyses. CONCLUSION: Reviews have concluded that EE is most effective when administered early in life but that EE during adulthood is certainly effective. Too few review studies have compared sexes for the effects of EE to make a statement about sex differences. Overall, articles reflect a lack of integration of information on age and sex differences in response to EE. Future studies of EE should examine both sexes and consider critical periods of the lifespan in the experimental models to facilitate the adequate translation of EE as a non-pharmaceutical intervention.

Beyond depression and anxiety; a systematic review about the role of corticotropin-releasing hormone antagonists in diseases of the pelvic and abdominal organs.

Evidence for beneficial effects of corticotropin releasing hormone (CRH) antagonists in abdominal and pelvic organs is emerging in preclinical studies. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement a compilation of preclinical studies using CRH receptor antagonists as a treatment for abdominal and pelvic disease was carried out. The Animal Research: Reporting of In Vivo Experiments (ARRIVE) essential 10 guidelines were used to determine quality of the included studies. A total of 40 studies from the last 15 years studying irritable bowel syndrome, inflammatory bowel disease, endometriosis, enteritis, stress impact on gastrointestinal processes and exogenous CRH administration effects were included. Blockage of the CRH receptor 1 was mainly associated with beneficial effects while that of CRH receptor 2 worsened studied effects. However, time of administration, route of administration and the animal model used, all had an impact on the beneficial outcomes. Frequency of drugs administered indicated that astressin-2B, astressin and antalarmin were among the most utilized antagonists. Of concern, studies included were predominantly carried out in male models only, representing a gender discrepancy in preclinical studies compared to the clinical scenario. The ARRIVE score average was 13 with ~60% of the studies failing to randomize or blind the experimental units. Despite the failure to date of the CRH antagonists in moving across the clinical trials pipeline, there is evidence for their beneficial effects beyond mood disorders. Future pre-clinical studies should be tailored towards effectively predicting the clinical scenario, including reduction of bias and randomization.

Feasibility and acceptability of an adapted environmental enrichment intervention for endometriosis: A pilot study.

Introduction: We have previously shown that Environmental Enrichment (EE)-consisting of social support, novelty, and open spaces-decreased disease progression and anxiety in a rat model of endometriosis. We developed a novel EE intervention to be tested in a pilot randomized clinical trial (RCT) in patients with endometriosis, a painful, stressful disease. Objective: To translate and evaluate the feasibility and acceptability of an adapted EE intervention as an adjuvant to standard-of-care for endometriosis patients. Methods: Feasibility was assessed through recruitment, enrollment, and adherence rates. Acceptability was evaluated through a post-intervention survey and focus group discussion 3-months after the end of the intervention. Results: Of the 103 subjects recruited, 64 were randomized to the intervention group and 39 to the control group. At the start of the intervention, the study groups consisted of 29 (intervention) and 27 (control) subjects. Enrollment rates were 45.3% and 69.2%, and adherence rates were 41.4% and 100% for the intervention and control groups, respectively. Delays resulting from natural events (earthquakes, the COVID-19 pandemic) impacted enrollment and adherence rates. The most common reasons for missing an intervention were period pain (39.1%) and work-study (34.8%). There was high acceptability (>80%) of the intervention's logistics. The majority (82.4%) of subjects would continue participating in support groups regularly, and 95.7% would recommend the intervention to other patients. Conclusions: We showed that EE could be translated into an acceptable integrative multi-modal therapy perceived as valuable among participants who completed the intervention. High attrition/low adherence indicates that additional refinements would be needed to improve feasibility. Acceptability data indicate that EE has the potential to be integrated into the clinical management of patients with endometriosis and other inflammatory, painful disorders. Studies are ongoing to assess the efficacy of EE in improving pain symptoms, mental health, and quality of life (QoL).

Hearing hoofbeats? Think head and neck trauma: a 10-year NTDB analysis of equestrian-related trauma in the USA.

OBJECTIVE: There is a paucity of evidence about traumatic injuries and their sequelae sustained due to equestrian injuries nationally. METHODS: Retrospective study analyzing National Trauma Data Bank data from 2007 to 2016. Variables collected included age, sex, race, payer status, Injury Severity Score (ISS), hospital length of stay, Glasgow Coma Scale, systolic blood pressure (SBP) at presentation, discharge disposition, and mortality. Patient data were analyzed by anatomic region. RESULTS: The most frequent type of injury was in the thorax, but head and neck injuries produced the highest mortality. Increased ISS and an SBP of less than 90 mm Hg were also significant predictors of mortality. CONCLUSIONS: The risk of hospital admission from equestrian injuries is higher than football, motor vehicle racing, and skiing. Preventive measures and campaigns should be instituted to highlight safety practices and the use of personal protective equipment while on horseback either for sports, leisure, or work. LEVEL OF EVIDENCE: Level IV. Retrospective study.

Predictors of Functional Outcome in a Cohort of Hispanic Patients Using Exoskeleton Rehabilitation for Cerebrovascular Accidents and Traumatic Brain Injury.

Traumatic brain injury (TBI) and cerebrovascular accidents (CVA) are two of the leading causes of disability in the United States. Robotic exoskeletons (RE) have been approved for rehabilitation by the Federal Drug Administration (FDA) for use after a CVA, and recently received approval for use in patients with TBI. The aim of the study was to determine which factors predict the improvement in functional independence measure (FIM) score after using RE rehabilitation in a population of patients with CVA or TBI. We carried out a retrospective chart-review analysis of the use of the RE (Ekso® GT) in the rehabilitation of patients with TBI and CVA using data from a single, private rehabilitation hospital for patients admitted and discharged between 01/01/2017 and 04/30/2020. From the medical records, we collected presentation date, Glasgow Coma Scale score (GCS) on the date of injury, rehabilitation start date, age, diabetes status on presentation (Yes or No), injury category (TBI or CVA), and both admission and discharge FIM scores. Matching algorithms resulted in one TBI patient matched to three CVA patients resulting in a sample size of 36. The diabetic and non-diabetic populations showed significant differences between age and days from injury to the start of rehabilitation. A multivariate linear regression assessed predictors for discharge motor FIM and found admission motor FIM score and total RE steps to be statistically significant predictors. For each point scored higher on the admission motor FIM the discharge FIM was increased by 1.19 FIM points, and for each 1,000 steps taken in the RE, the discharge motor FIM increased by three points. The type of acquired brain injury (CVA or TBI) was not found to affect functional outcome. The presented results show that key clinic-biologic factors including diabetic status, together with start to rehabilitation play key roles in discharge FIM scores for patients using RE. Clinical Trial Registration: ClinicalTrials.gov, NCT04465019.

Delayed Presentation of Patients with Hip Fractures during the COVID-19 "Stay-at-Home" Order in the Southmost Region of the United States.

To evaluate the effects of COVID-19 and stay-at-home orders in traumatic hip fractures presentation, we conducted a retrospective chart review cohort study from March 13 to June 13 in 2020 compared to 2019 from a single-hospital Trauma Level 2 Center. Males and females, 18 years of age and older presenting with a diagnosis of displaced or nondisplaced, intracapsular, or extracapsular hip fracture, underwent standard of care-comparative analysis of the patient's characteristics and clinical outcomes. The primary study outcomes included age, sex, ethnicity, and body mass index, the onset of injury, date of arrival, payer, the primary type of injury and comorbidities, mechanism of injury, treatment received, postoperative complications, days in an intensive care unit (ICU), discharge disposition, pre- and postinjury functional status, and COVID-19 test. Age, sex, ethnicity, and body mass index were similar in the patients in 2019 compared to 2020. The patients' average age was 76 years old, 80% reported Hispanic ethnicity, and 63% of the patients were females. Most injuries (90%) occurred due to falls. On average, patients in 2020 presented 4.8 days after the injury onset as compared to 0.7 days in 2019 (p < 0.05). There was an increase in displaced fractures in 2019 compared to 2020 and an increase in patients' disposition into rehabilitation facilities compared to skilled nursing facilities. Despite the delay in presentation, length of stay, days in the ICU, or functional outcomes of the patients were not affected. Although the patients showed a delayed presentation after hip fracture, this does not appear to significantly interfere with the short-term or the 6-month mortality outcomes of the patients, suggesting the possibility of guided delayed care during times of national emergency and increased strain in hospital resources.

Complications and Comorbidities in Hispanic Patients Who Develop Traumatic and Non-traumatic Acute Compartment Syndrome.

Acute compartment syndrome (ACS) is a medical emergency that remains under-recognized and understudied. This study aimed to identify risk factors for the traumatic and non-traumatic presentation of ACS within a majority Hispanic population. A four-year retrospective analysis of medical records in a single institution revealed 26 with traumatic and 21 non-traumatic patients presenting with ACS. Traumatic ACS occurred in younger males following fractures, as previously described in the field. After controlling for age differences, non-traumatic ACS occurred in older patients with multiple comorbidities, increased use of statins, and anticoagulants as compared to the traumatic ACS group. A large proportion (80%) of the non-traumatic ACS group also presented with hypertension. Patients taking anticoagulants and statins should be carefully monitored for ACS development after non-traumatic qualifying events and advanced age. Further studies should identify how statins interact with the patients' racial/ethnic profile and the incidence of comorbidities to promote earlier identification and reduce morbidities.

Metabolomics in endometriosis: challenges and perspectives for future studies.

Endometriosis is a complex disease characterized by inflammation and the growth of endometrial- like glands and stroma outside the uterine cavity. The pathophysiology of endometriosis is not entirely understood, however, with a prevalence of ~10% of women in their reproductive years, the disease symptoms significantly affect the quality of life of millions of women globally. Metabolomic studies have previously identified specific metabolites that could be a signature of endometriosis. This approach could potentially be used as a non-invasive tool for early diagnosis and provide a better understanding of endometriosis pathophysiology. This review aims to provide insight as to how endometriosis affects the metabolome by reviewing different studies that have used this approach to design follow-up studies. The search query included the term 'endometriosis' in combination with 'metabolomics', 'lipidomics', or 'sphingolipidomics' published between 2012 and 2020. We included studies in humans and animal models. Most studies reported differences in the metabolome of subjects with endometriosis in comparison to healthy controls and used samples taken from serum, endometrial tissue, follicular fluid, urine, peritoneal fluid, or endometrial fluid. Statistically significant metabolites contributed to group separation between patients and healthy controls. Reported metabolites included amino acids, lipids, organic acids, and other organic compounds. Differences in methods, analytical techniques, and the presence of confounding factors can interfere with results and interpretation of data. Metabolomics seems to be a promising tool for identifying significant metabolites in patients with endometriosis. Nonetheless, more investigation is needed in order to understand the significance of the study results. LAY SUMMARY: Endometriosis is a chronic disease affecting the quality of life in one out of every ten women during their reproductive years, causing pain and infertility. It is characterized by inflammation and growth of tissue like the endometrium (uterus lining) outside the uterine cavity. Studies have searched for a predictor of endometriosis-associated changes by observing small molecules necessary for metabolism on a large scale (metabolomics). Metabolomics could serve to resolve one of the biggest challenges that patients with endometriosis face: a delay in diagnosis. In this review, the authors summarize identified potential biomarkers from various bodily fluids and tissues that are characteristic of metabolic processes observed in endometriosis. Biomarkers include cell growth, cell survival, high energy demand, oxidative stress, and fatty acid levels. A metabolomics approach offers promise as a non-invasive tool to identify significant metabolite changes in patients with endometriosis, potentially leading to earlier diagnoses and new opportunities for back-translational strategies.

Effectiveness of Pharmacological Agents and Validation of Diagnostic Scales for the Management of Paroxysmal Sympathetic Hyperactivity in Hispanics.

The identification and treatment of paroxysmal sympathetic hyperactivity (PSH) still present a significant challenge. We assessed the efficacy of pharmacological agents in treating PSH symptoms and the validity of the diagnostic scales in a cohort of Hispanic patients. A retrospective chart review of cases from a single hospital was conducted in 464 records. Exclusion criteria included underlying conditions such as severe infection. Only nine patients remained in the cohort after examining their clinical records, corresponding to the following diagnoses: traumatic brain injury, subdural hemorrhage, anoxic or ischemic encephalopathy, pneumocephalus, and cerebral palsy. Using the PSH likelihood scale, six of the nine patients were identified with a score of 17 or higher, corresponding to a "probable" PSH, and three patients obtained a score between 8 and 16, corresponding to a "possible" PSH diagnosis. The top three classes of medications used were beta-blockers, antipyretics, and opioids. Benzodiazepines and neuromodulators were also frequently used in patients with trauma, but not in the ones with non-traumatic injuries. Interestingly, 75% of the patients have prescribed levothyroxine as a home medication after the PSH presentation. Medication administration did not follow a specific pattern, suggesting high variability in the management of PSH within our setting, requiring further research. Our results suggest that the pituitary axis might be involved in the progression of PSH. Establishing a specific medical code (e.g., ICD-10) describing PSH as a single entity is essential for appropriate identification and management.

The Link Between Stress and Endometriosis: from Animal Models to the Clinical Scenario.

There is strong evidence from humans and animal models showing that abnormal functioning of the hypothalamic-pituitary-adrenal (HPA) axis and/or the inflammatory response system disrupts feedback regulation of both neuroendocrine and immune systems, contributing to disease. Stress is known to affect the physiology of pelvic organs and to disturb the HPA axis leading to chronic, painful, inflammatory disorders. A link between stress and disease has already been documented for many chronic conditions. Endometriosis is a complex chronic gynecological disease associated with severe pelvic pain and infertility that affects 10% of reproductive-aged women. Patients report the negative impact of endometriosis symptoms on quality of life, work/study productivity, and personal relationships, which in turn cause high levels of psychological and emotional distress. The relationship between stress and endometriosis is not clear. Still, we have recently demonstrated that stress increases the size and severity of the lesions as well as inflammatory parameters in an animal model. Furthermore, the "controllability" of stress influences the pathophysiology in this model, offering the possibility of using stress management techniques in patients. The crosstalk between stress-inflammation-pain through HPA axis activity indicates that stress relief should alleviate inflammation and, in turn, decrease painful responses. This opens up the opportunity of altering brain-body-brain pathways as potential new therapeutic option for endometriosis. The goal of this review is to gather the research evidence regarding the interaction between stress (psychological and physiological) and the development and progression of endometriosis on the exacerbation of its symptoms with the purpose of proposing new lines of emerging research and possible treatment modalities for this still incurable disease.

Racial inequality in the trauma of women: A disproportionate decade.

BACKGROUND: Historically, women have been largely underrepresented in the body of medical research. Given the paucity of data regarding race and trauma in women, we aimed to evaluate the most common types of traumas incurred by women and analyze temporal racial differences. METHODS: A 10-year review (2007-2016) of the National Trauma Data Bank was conducted to identify common mechanisms of injuries among women. Trends of race, intent of injury, and firearm-related assaults were assessed using the Cochran-Armitage Trend test. Multivariable multinomial logistic regressions were utilized to examine the association between race and trauma subtypes. RESULTS: Of the 2,082,768 women identified as a trauma during this study period, the majority presented due to an unintentional intent (94.5%), whereas fewer presented secondary to an assault (4.4%) or self-inflicted injury (1.1%). While racioethnic minority women encompassed a small percentage of total traumas (19%), they accounted for roughly three fifths of assault-related traumas (p < 0.001). Though total assaults decreased by 20.8% during the study period, black and Hispanic women saw a disproportionately smaller decrease of 15.1% and 15.8%, respectively. On regression analysis, compared with white women, black women had more than four times the odds of being an assault-related trauma compared with unintentional trauma (odds ratio, 4.48; 95% confidence interval, 4.41-4.55). On subset analysis, firearm-related assault was 17.3 times more prevalent among black women (white, 0.3% vs. black: 5.2%; p < 0.001). In fact, history of alcohol abuse was found to be an effect modifier of the association of race/ethnicity and firearm-related trauma. CONCLUSION: Compelling data highlight a disproportionate trend in the assault-related trauma of minority women. Specifically, minority women, especially those with a history of alcohol abuse, were at increased risk of being involved in a firearm assault. Further studies are essential to help mitigate disparities and subsequently develop preventative services for this diverse population. LEVEL OF EVIDENCE: Epidemiological, Level III.

Short treatment with antalarmin alters adrenal gland receptors in the rat model of endometriosis.

Endometriosis is a chronic inflammatory disorder in which endometrial tissue is found outside the uterine cavity. Previous reports suggest that there is a dysregulation of the hypothalamic pituitary adrenal axis during the progression of endometriosis. Our previous report showed that a short-term treatment with antalarmin, a corticotrophin releasing hormone receptor type 1 (CRHR1) antagonist decreases the number and size of endometriotic vesicles in the auto-transplantation rat model of endometriosis. Our current goal was to examine the mRNA expression of intra-adrenal receptors to better understand the mechanisms of the hypothalamic pituitary adrenal (HPA) axis involvement in endometriosis. We used two groups of female rats. The first received sham surgery or endometriosis surgery before collecting the adrenals after 7 days of the disease progression. The second group of animals received endometriosis surgery and a treatment of either vehicle or antalarmin (20 mg/kg, i.p.) during the first 7 days after endometriosis induction and then the disease was allowed to progress until day 60. Rats with sham surgery served as controls. Results showed that the mRNA expression of the mineralocorticoid (MRC2) receptor was lower in the rats after 7 days of endometriosis surgery and in rats with endometriosis that received antalarmin. In addition, the CRHR1 was significantly elevated in animals that received antalarmin and this was counteracted by a non-significant elevation in CRHR2 mRNA. The glucocorticoid receptor mRNA within the adrenals was not affected by endometriosis or antalarmin treatment. This report is one of the first to explore intra-adrenal mRNA for receptors involved in the HPA axis signaling as well as in the sympatho-adrenal signaling, calling for additional research towards understanding the role of the adrenal glands in chronic inflammatory diseases such as endometriosis.

Effects of Environmental Enrichment in Maternally Separated Rats: Age and Sex-Specific Outcomes.

Maternal separation (MS) early in life is related to an increase in anxiety and depressive-like behaviors and neurobiological alterations mostly related to alterations in hypothalamic pituitary adrenal (HPA) axis reactivity. Environmental enrichment (EE) has been used to ameliorate the effects of MS. However, the outcomes of this intervention at different developmental periods after MS have not been studied. We subjected male and female Sprague-Dawley pups to MS and subsequently compared the effects of EE started either in the pre-pubertal period [postnatal day (PND) 22] or adulthood (PND 78). Anxiety and depressive-like behaviors as well as in hippocampal synaptic density and basal corticosterone, oxytocin, and vasopressin levels were measured. Our results support the beneficial effects of adulthood EE in decreasing anxiety in males as well as promoting synaptic density in ventral hippocampal CA3. Males displayed higher levels of vasopressin while females displayed higher oxytocin, with no changes in basal corticosterone for any group after EE.

Influence of biological sex on social behavior, individual recogntion, and non-associative learning in the adult gray short-tailed opossum (Monodelphis domestica).

Social behavior is critical for relationship formation and is influenced by myriad environmental and individual factors. Basic and preclinical research typically relies on rodent models to identify the mechanisms that underlie behavior; however, it is important to use non-rodent models as well. A major objective of the present study was to test the hypothesis that biological sex and social experience modulate the expression of social behavior in the adult gray short-tailed opossum (Monodelphis domestica), a non-traditional model. We also investigated the non-associative learning abilities of these animals. Following a period of social isolation, animals of both sexes were paired with a non-familiar, same-sex partner for 10 min on three different occasions, with 24-hour inter-trial intervals. We are the first research group to find significant sex differences in submissive and nonsocial behaviors in Monodelphis. Females displayed significantly higher durations of nonsocial behavior that increased over trials. Males were more aggressive; their latencies to the first attack and submissive behavior decreased over trials whereas these latencies increased for females; males' duration of submissive behavior increased over trials whereas it decreased for females. A different group of subjects habituated in response to repeated presentations to neutral odors and dishabituated in response to novel odors. In addition, both males and females demonstrated the ability to form social memories in a standard individual (social) recognition test. Our results contribute to the characterization of this marsupial species, an important first step in developing it as a model of complex social behaviors.

Correction to: Mind, Brain, and Behavior: an Integrative Approach to Teaching Neuroscience to Medical Students.

This article was updated to correct Ignacio Martinez Escobedo's name.