Sexual differentiation of neural mechanisms of stress sensitivity during puberty.

Anxiety disorders are a major public health concern and current treatments are inadequate for many individuals. Anxiety is more common in women than men and this difference arises during puberty. Sex differences in physiological stress responses may contribute to this variability. During puberty, gonadal hormones shape brain structure and function, but the extent to which these changes affect stress sensitivity is unknown. We examined how pubertal androgens shape behavioral and neural responses to social stress in California mice (Peromyscus californicus), a model species for studying sex differences in stress responses. In adults, social defeat reduces social approach and increases social vigilance in females but not males. We show this sex difference is absent in juveniles, and that prepubertal castration sensitizes adult males to social defeat. Adult gonadectomy does not alter behavioral responses to defeat, indicating that gonadal hormones act during puberty to program behavioral responses to stress in adulthood. Calcium imaging in the medioventral bed nucleus of the stria terminalis (BNST) showed that social threats increased neural activity and that prepubertal castration generalized these responses to less threatening social contexts. These results support recent hypotheses that the BNST responds to immediate threats. Prepubertal treatment with the nonaromatizable androgen dihydrotestosterone acts in males and females to reduce the effects of defeat on social approach and vigilance in adults. These data indicate that activation of androgen receptors during puberty is critical for programming behavioral responses to stress in adulthood.

Timing of the luteal-placental shift is delayed with additional fetuses in litter-bearing callitrichid monkeys, Saguinus oedipus and Callithrix jacchus.

The luteal-placental shift is an important milestone of mammalian pregnancy signifying when endocrine control of pregnancy shifts from the corpus luteum of the ovary to the placenta. The corpus luteum is maintained by chorionic gonadotropin (CG). Upon sufficient placental maturation, CG production wanes, the corpus luteum involutes, and control is shifted to the placenta, one consequence of which is a midgestational rise in glucocorticoid production, especially cortisol and cortisone, by both mother and fetus. Glucocorticoids are involved in initiating parturition, prenatal programming of offspring phenotype, and maturing fetal organs. Limited evidence from human pregnancy suggests that the timing of this shift is delayed in twin pregnancies, but little is known about the timing of the luteal-placental shift in litter-bearing monkeys from the primate family Callitrichidae. Here we provide evidence from cotton-top tamarins (Saguinus oedipus) and common marmosets (Callithrix jacchus) of longer duration of elevated CG associated with multiple infant births compared to single births. Urinary profiles from cotton-top tamarins demonstrate that the decline of the extended elevation of CG precedes the onset of the midpregnancy sustained rise in glucocorticoids; this shift occurs later with an increase from one to two fetuses carried to term. In the common marmoset, the onset of the sustained rise of glucocorticoids in maternal urine is also delayed with an increase in infant number. Total urinary glucocorticoid levels during the last half of gestation increase monthly but do not differ by infant number. The significant delay in the luteal-placental shift suggests a longer period of placental maturation is needed to support a greater number of fetuses.

Getting under the skin: Physiological stress and witnessing paternal arrest in young children with incarcerated fathers.

U.S. jails see nearly 11 million annual admissions, rates that disproportionately affect men of color-more than half of whom are fathers. An estimated 7% of U.S. children experience the incarceration of a parent, increasing their risk for poor developmental and health outcomes. Although stress processes are often suggested as an underlying mechanism linking paternal incarceration to child well-being, few studies have examined such links. To study how witnessing a father's arrest prior to incarceration in jail relates to children's stress processes, we collected data on 123 individuals from 41 families with young children whose father was in jail, including collecting hair from 41 children, and analyzed their cumulative stress hormones, cortisol, and cortisone. Results indicate that children had higher cumulative stress hormone concentrations when they witnessed their father's arrest. Moreover, there was evidence of a blunted stress reaction in children who witnessed the arrest and who also had high levels of ongoing behavioral stress symptoms, similar to findings in Post-Traumatic Stress Disorder studies. Long-term exposure to stress can have deleterious effects on children's brain development, further increasing risk for developmental psychopathology. Findings have implications for criminal justice approaches that safeguard children during parental arrest.

Cognitively-Based Compassion Training for parents reduces cortisol in infants and young children.

This study tests a group-based secular contemplative practice intervention, Cognitively-Based Compassion Training (CBCT), with parents of young children. We report on a randomized controlled preliminary efficacy study. Certified teachers administered CBCT for 20 hr across 8 to 10 weeks in two cohorts of parents with infants and young children. The intervention group was compared to a waitlist control group. Thirty-nine parents and their children, who ranged in age from 4 months to 5 years, were evaluated at pre- and postintervention (n = 25 intervention, n = 14 waitlist control) on hair cortisol concentration. Parents also completed self-administered questionnaires at both time points regarding demographics, physical symptoms of stress, parenting stress, self-compassion, and mindfulness. Children of parents in the CBCT group experienced significant decreases in cortisol at the postintervention assessment, as compared with the control group. However, parent cortisol and self-report measures did not significantly change other than a small effect on clinical levels of parenting stress. CBCT may be a positive new way to intervene with parents to lower infants' and young children's cumulative physiological stress.

Este estudio puso a prueba una práctica de intervención contemplativa secular con base en un grupo, el Entrenamiento Compasivo con Base Cognitiva (CBCT), con padres de niños pequeños. Nosotros reportamos sobre un estudio de efectividad preliminar controlado al azar. Maestros titulados administraron el CBCT por 20 horas a lo largo de 8-10 semanas en dos grupos de padres con infantes y niños pequeños. El grupo de intervención fue comparado con un grupo de control en lista de espera. Treinta y nueve padres y sus niños, que oscilaban en edad de 4 meses a 5 años, fueron evaluados antes y después de la intervención (n=25 grupo de intervención, n=14 grupo de control en lista de espera) en cuanto a la concentración de cortisol en el cabello. Los padres también completaron cuestionarios auto-administrados en ambos momentos temporales con respecto a información demográfica, síntomas físicos de estrés, estrés de crianza, auto-compasión, así como plena conciencia. Los niños de padres en el grupo CBCT experimentaron una significativa disminución de cortisol al momento de la evaluación posterior a la intervención, tal como se les comparó con el grupo de control. Sin embargo, el cortisol de los padres y las medidas de auto-reporte no cambiaron significativamente. El CBCT pudiera ser una nueva manera positiva de intervenir con padres para reducir el estrés fisiológico cumulativo de infantes y niños pequeños.

Cette étude a testé une intervention de pratique contemplative séculaire et basée sur un groupe, la Formation de Compassion Cognitive (abrégé ici selon l'anglais CBCT), avec des parents de jeunes enfants. Cet article porte sur une étude d'efficacité préliminaire randomisée et contrôlée. Des formateurs certifiés ont procédé à une CBCT de 20 heures réparties sur 8-10 semaines chez deux cohortes de parents avec des nourrissons et des jeunes enfants. Le groupe d'intervention a été comparé à un groupe de contrôle en liste d'attente. Trente-neuf parents et leurs enfants, allant de 4 mois à 5 ans d'âge, ont été évalués avant et après l'intervention (n=25 intervention, n=14 contrôle de liste d'attente) sur la concentration de cortisol capillaire. Les parents ont également rempli des questionnaires auto-administrés aux deux temps d'évaluation, concernant des données démographiques, les symptômes physiques de stress, le stress de parentage, l'auto-compassion et la pleine conscience. Les enfants de parents du groupe CBCT ont fait preuve de baisses de niveau de cortisol importantes à l'évaluation post-intervention en comparaison au groupe de contrôle. Cependant le cortisol parental et les mesures auto-rapportées n'ont pas changé de manière importante. La CBCT peut être une nouvelle manière positive d'intervenir avec les parents afin de faire baisser le stress physiologique cumulatif des nourrissons et des jeunes enfants.

Hypocalcemia and Vitamin D Deficiency amongst Migraine Patients: A Nationwide Retrospective Study.

Background and Objectives: Inadequate vitamin D and calcium intake have been linked to many health issues including chronic headaches. Some studies suggested an association between low vitamin D levels and increase the risk of frequent headaches in middle-aged and older men; however, no single study reported the role of these deficiencies in migraine patients. We aimed to investigate the association of hypocalcemia and vitamin D deficiency with migraine hospitalizations. Materials and Methods: A population-based retrospective cross-sectional analysis of the Nationwide Inpatient Sample (NIS) (years 2003-2014) in migraine hospitalizations was performed. The prevalence, demographic characteristics and All Patient Refined Diagnosis Related Groups severity/disability association were compared in patients with hypocalcemia and vitamin D deficiency to those without deficiencies, using ICD-9-CM codes. Weighted analyses using Chi-Square, paired Student's t-test, and Cochran-Armitage trend test were performed. Survey logistic regression was performed to find an association between deficiencies and migraine hospitalizations and deficiency induced disability amongst migraineurs. Results: Between years 2003 and 2014, of the total 446,446 migraine hospitalizations, 1226 (0.27%) and 2582 (0.58%) presented with hypocalcemia and vitamin D deficiency, respectively. In multivariable analysis, hypocalcemia [Odds Ratio (OR): 6.19; Confidence Interval (CI): 4.40-8.70; p < 0.0001] and vitamin D deficiency (OR: 3.12; CI: 2.38-4.08; p < 0.0001) were associated with markedly elevated odds of major/extreme loss of function. There was higher prevalence (3.0% vs. 1.5% vs. 1.6%; p < 0.0001) and higher odds of migraine among vitamin D deficiency (OR: 1.97; CI: 1.89-2.05; p < 0.0001) patients in comparison to patients with hypocalcemia (OR: 1.11; CI: 1.03-1.20; p = 0.0061) and no-deficiency, respectively. Conclusions: In this study, we demonstrated a significant association between hypocalcemia and vitamin D deficiency with migraine attacks and deficiency induced loss of function among migraineurs. Early preventive measures may reduce the disability in migraineurs.

Comparison of vitamin D metabolites in wild and captive baboons.

Vitamin D adequacy is essential for multiple physiologic processes. With limited exposure to sunlight for vitamin D3 synthesis, captive primates are supplemented with vitamin D3 (cholecalciferol). Vitamin D metabolite data from wild primates living indigenously could suggest optimum levels. The purpose of this study was to: 1) to explore whether baboons, a speciose genus whose members have significant exposed skin, coat color variation and wide geographical distribution, mirrors the skin pigmentation-vitamin D relationship found in humans; 2) compare vitamin D metabolite levels in wild and captive members of the same or similar baboon species; and 3) apply a recently developed method currently used in humans for measuring multiple vitamin D metabolites as a panel to explore if/how these metabolites can inform us on vitamin D sufficiency. Serum samples from males of three baboon species in the wild: Papio anubis (olive baboon, dark exposed skin), P. cynocephalus (yellow baboon, brown exposed skin), and P. hamadryas (hamadryas baboon, pink exposed skin), were compared with vitamin D supplemented captive olive baboons with sun exposure. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) measured vitamin D and its main metabolites. Cholecalciferol, 25 hydroxyvitamin D2&3 (25(OH)D2&3 ), and 24,25 dihydroxyvitamin D2&3 (24,25(OH)2 D2&3 ), showed significant differences by species. The levels of cholecalciferol due to supplements in the captive olive baboons did not convert to higher 25(OH)D3 while the wild olive baboons exhibited the lowest levels for both cholecalciferol and 25(OH)D3 . Further metabolic conversion of 25(OH)D3 to 24,25(OH)2 D3 indicated that all baboons had more similar conversion ratios and these were within the same range found for humans that are depicted as having adequate vitamin D levels. This study provided evidence that exposed skin color does influence vitamin D3 levels, with lower levels in darker skinned species, but these differences are eliminated in the downstream metabolite conversion indicating strong regulatory control.

Extraovarian gonadotropin negative feedback revealed by aromatase inhibition in female marmoset monkeys.

Whereas the ovary produces the majority of estradiol (E2) in mature female primates, extraovarian sources contribute to E2 synthesis and action, including the brain E2-regulating hypothalamic gonadotropin-releasing hormone. In ovary-intact female rodent models, aromatase inhibition (AI) induces a polycystic ovary syndrome-like hypergonadotropic hyperandrogenism due to absent E2-mediated negative feedback. To examine the role of extraovarian E2 on nonhuman primate gonadotropin regulation, the present study uses letrozole to elicit AI in adult female marmoset monkeys. Sixteen female marmosets (Callithrix jacchus; >2 yr) were randomly assigned to ovary-intact or ovariectomy (OVX) conditions and subsequently placed on a daily oral regimen of either ~200 µl vehicle alone (ovary-intact Control, n = 3; OVX, n = 3) or 1 mg ⋅ kg-1 ⋅ day-1 letrozole in vehicle (ovary-intact AI, n = 4; OVX + AI, n = 6). Blood samples were collected every 10 days, and plasma chorionic gonadotropin (CG) and steroid hormone levels were determined by validated radioimmunoassay and liquid chromatography/tandem mass spectrometry, respectively. Ovary-intact, AI-treated and OVX females exhibited elevated CG (P < 0.01, P = 0.004, respectively) compared with controls, and after 30 days, OVX + AI females exhibited a suprahypergonadotropic phenotype (P = 0.004) compared with ovary-intact + AI and OVX females. Androstenedione (P = 0.03) and testosterone (P = 0.05) were also elevated in ovary-intact, AI-treated females above all other groups. The current study thus confirms in a nonhuman primate that E2 depletion and diminished negative feedback in ovary-intact females engage hypergonadotropic hyperandrogenism. Additionally, we demonstrate that extraovarian estrogens, possibly neuroestrogens, contribute to female negative feedback regulation of gonadotropin release.

Low Lactobacilli abundance and polymicrobial diversity in the lower reproductive tract of female rhesus monkeys do not compromise their reproductive success.

The lower reproductive tract of nonhuman primates is colonized with a diverse microbiota, resembling bacterial vaginosis (BV), a gynecological condition associated with negative reproductive outcomes in women. Our 4 aims were to: (i) assess the prevalence of low Lactobacilli and a BV-like profile in female rhesus monkeys; (ii) quantify cytokines in their cervicovaginal fluid (CVF); (iii) examine the composition and structure of their mucosal microbiota with culture-independent sequencing methods; and (iv) evaluate the potential influence on reproductive success. CVF specimens were obtained from 27 female rhesus monkeys for Gram's staining, and to determine acidity (pH), and quantify proinflammatory cytokines. Based on Nugent's classification, 40% had a score of 7 or higher, which would be indicative of BV in women. Nugent scores were significantly correlated with the pH of the CVF. Interleukin-1ß was present at high concentrations, but not further elevated by high Nugent scores. Vaginal swabs were obtained from eight additional females to determine microbial diversity by rRNA gene amplicon sequencing. At the phylum level, the Firmicutes/Bacteroidetes ratio was low. The relative abundance of Lactobacilli was also low (between 3% and 17%), and 11 other genera were present at >1%. However, neither the microbial diversity in the community structure, nor high Nugent scores, was associated with reduced fecundity. Female monkeys provide an opportunity to understand how reproductive success can be sustained in the presence of a diverse polymicrobial community in the reproductive tract.

Measurement of 25-hydroxyvitamin D(2&3) and 1,25-dihydroxyvitamin D(2&3) by tandem mass spectrometry: A primate multispecies comparison.

Vitamin D metabolites are widely studied for their roles in bone health, immune functions, and other potential physiologic roles in humans. However, the optimal blood levels of vitamin D metabolites are still unclear. Various methods for measuring vitamin D metabolites have been used and recently liquid chromatography tandem mass spectroscopy (LC-MS/MS) has been adopted as the gold standard for vitamin D metabolite measurement. Here, we report the use of LC-MS/MS to measure 25-hydroxyvitamin D (25(OH)D(2&3)), and 1,25-dihydroxyvitamin D (1,25(OH)2D(2&3)), in three laboratory nonhuman primate species: common marmoset (Callithrix jacchus), rhesus macaque (Macaca mulatta), and cynomolgus macaque (Macaca fascicularis), and compare them to humans using the same technique. The nonhuman primates showed blood levels for 25(OH)D3 and 1,25(OH)2D3 significantly higher than human values with marmosets having the highest levels. Marmoset samples showed significantly more variability among individuals than those from macaques for both metabolites, but all three nonhuman primate species exhibited large variation within species for both 25(OH)D(2&3) and 1,25(OH)2D(2&3). Marmoset females had significantly lower values than the males for 25(OH)D3, while rhesus males showed a significant decrease in 25(OH)D3 with age. The most striking finding is the variation within species for vitamin D levels even in laboratory primates that have a controlled diet, UV exposure, and in some cases, genetic constraints. Similar variation in 25(OH)D responses to a fixed dose of oral vitamin D supplementation has been reported in humans. We suggest that these species can provide primate models for examining the factors influencing variation in the levels of vitamin D necessary for human and nonhuman primate health.

Neuroestradiol in the hypothalamus contributes to the regulation of gonadotropin releasing hormone release.

Release of gonadotropin releasing hormone (GnRH) from the medial basal hypothalamus (MBH)/median eminence region (S-ME) is essential for normal reproductive function. GnRH release is profoundly regulated by the negative and positive feedback effects of ovarian estradiol (E2). Here we report that neuroestradiol, released in the S-ME, also directly influences GnRH release in ovariectomized female monkeys, in which the ovarian source of E2 is removed. We found that (1) brief infusion of E2 benzoate (EB) to the S-ME rapidly stimulated release of GnRH and E2 in the S-ME of ovariectomized monkeys, (2) electrical stimulation of the MBH resulted in GnRH release as well as E2 release, and (3) direct infusion of an aromatase inhibitor to the S-ME suppressed spontaneous GnRH release as well as the EB-induced release of GnRH and E2. These findings reveal the importance of neuroestradiol as a neurotransmitter in regulation of GnRH release. How circulating ovarian E2 interacts with hypothalamic neuroestrogens in the control of GnRH release remains to be investigated.

Hormones in infant rhesus monkeys' (Macaca mulatta) hair at birth provide a window into the fetal environment.

BACKGROUND: It is established that maternal parity can affect infant growth and risk for several disorders, but the prenatal endocrine milieu that contributes to these outcomes is still largely unknown. Recently, it has been shown that hormones deposited in hair can provide a retrospective reflection of hormone levels while the hair was growing. Taking advantage of this finding, our study utilized hair at birth to investigate if maternal parity affected fetal hormone exposure during late gestation. METHODS: Hair was collected from primiparous and multiparous mother and infant monkeys at birth and used to determine steroid hormones embedded in hair while the infant was in utero. A high-pressure liquid chromatography-triple quadrupole mass spectrometry technique was refined, which enabled the simultaneous measurement of eight hormones. RESULTS: Hormone concentrations were dramatically higher in neonatal compared to maternal hair, reflecting extended fetal exposure as the first hair was growing. Further, hair cortisone was higher in primiparous mothers and infants when compared to the multiparous dyads. CONCLUSION: This research demonstrates that infant hair can be used to track fetal hormone exposure and a panel of steroid hormones can be quantified from hair specimens. Given the utility in nonhuman primates, this approach can be translated to a clinical setting with human infants.

A fit-for-purpose validation of a commercial radioimmunoassay for measurement of human peripheral oxytocin.

Oxytocin (OT) is a peptide hormone synthesized in the hypothalamus and released into systemic circulation or other areas of the brain. Its physiological roles include action as a hormone with stimulation of uterine contractions and that as a neuromodulator with involvement in social behaviors and regulation of mood. Its small size and low levels within biological matrices make it challenging to accurately measure. The goal of this study was to demonstrate the specificity of the antibody, sensitivity, and reproducibility of the Phoenix Pharmaceuticals (PP) OT radioimmunoassay (RIA) for use in human urine, serum, and saliva. Specificity of the antibody was assessed by high pressure liquid chromatography with ultraviolet (HPLC-UV) separation and assay of the fractions. Immunoreactivity was evaluated using the percent OT bound, and the fraction retention times were compared to the retention time of an intact OT standard to determine which fractions contained OT in the extracted samples. Reproducibility was assessed by running replicates of pools of each biomatrix over several assays. Sensitivity was assessed by repeated measurement of physiologically relevant low-concentration specimens. In all tested specimens the greatest reactivity in assay corresponded to the same fraction(s) as the OT standard. Only minimal reactivity was found in the other fractions, suggesting that in an unfractionated sample the antibody reacts mostly with intact OT. Reproducibility was acceptable for all specimens and the coefficient of variation (CV) ranged from 3.72 to 8.04% and 5.89-12.8%, for intra and inter-assay, respectively. The limits of quantitation (LOQ) were sufficient for measurement of normal values in urine (0.643 & 1.43 pg/mL), serum (1.90 pg/mL), and saliva pools (0.485 & 4.42 pg/mL). In conclusion, the PP OT RIA is specific and sensitive enough for reproducible measurement of intact OT in human peripheral biological matrices.

Exploring Inflammation and Stress as Biological Correlates of Symptoms in Children With Advanced Cancer: A Longitudinal Feasibility Study.

Background: Few studies have examined biomarkers of stress and inflammation as underlying mechanisms of symptoms in adolescents and young adults with cancer. This study determined the feasibility of collecting blood and saliva samples across time, described the range and distribution of biomarkers, and explored the association of biomarkers with symptom adverse events (AEs). Method: This longitudinal, prospective repeated-measures single-site feasibility study recruited N = 10 children (M = 12.5 years) receiving treatment for advanced cancer. Symptom AE data and inflammation (cytokines and C-reactive protein) and physiologic response to stress (salivary cortisol and salivary alpha-amylase) biomarker levels were collected at three time points. Descriptive statistics were used to examine feasibility and acceptability and to summarize symptom AE, stress, and inflammatory biomarker data. A linear regression model was used to determine cortisol diurnal slopes. The relationship between symptom and inflammatory biomarker data was explored and Hedges's g statistic was used to determine its effect size. Results: Participants provided 83% of saliva samples (n = 199/240) and 185 samples were sufficient to be analyzed. Nurses collected 97% (n = 29/30) of blood samples. Participants reported the saliva collection instructions, kits, and reminders were clear and helpful. Insomnia, pain, fatigue, and anxiety demonstrated the most medium and large negative effects with inflammatory markers. Symptom AEs demonstrated the highest number of medium and large negative effects with interleukin-8 and tumor necrosis factor-alpha (-0.53 to -2.00). Discussion: The results indicate longitudinal concurrent collection of symptom and biomarker data is feasible and inflammatory and stress biomarkers merit consideration for inclusion in future studies.

Key Considerations for Studying the Effects of High-Fat Diet on the Nulligravid Mouse Endometrium.

The obesity epidemic continues to increase, with half of US women predicted to be obese by 2030. Women with obesity are at increased risk for not only cardiovascular and liver disease, but also reproductive disorders. Although mouse models are useful in studying the effects of obesity, there is inconsistency in obesity-induction methods, diet composition, and mouse strains, and studies using female mice are limited. In this study, we sought to compare the effects of a 45% high-fat diet (HFD) versus a 60% HFD on the uterine estrous cycle of nulligravid C57BL/6J mice. For 22 weeks, we placed a total of 20 mice on either a 60% HFD, 45% HFD, or each HFD-matched control diet (CD). Both HFDs produced significant weight gain, with 60% HFD and 45% HFD gaining significant weight after 2 weeks and 15 weeks, respectively. Additionally, both HFDs led to glucose intolerance, fatty liver, and adipocyte hypertrophy. Mice fed 60% HFD displayed hyperphagia in the first 12 weeks of HFD treatment. Moreover, 60% HFD-treated mice had a longer estrous cycle length and an increased percentage of estrus stage samplings compared to CD-treated mice. Estrous cycle stage-controlled 60% HFD-treated mice displayed an increased estrogen-to-progesterone ratio and decreased ovarian corpora lutea compared to CD-treated mice, which may underlie the observed estrous cycle differences. There was no significant difference between diets regarding endometrial morphology or the percent of endometrial CD45+ immune cells. Our results indicate that consideration is needed when selecting a HFD-induced obesity mouse model for research involving female reproductive health.

Proximal cerebral arteries develop myogenic responsiveness in heart failure via tumor necrosis factor-α-dependent activation of sphingosine-1-phosphate signaling.

BACKGROUND: Heart failure is associated with neurological deficits, including cognitive dysfunction. However, the molecular mechanisms underlying reduced cerebral blood flow in the early stages of heart failure, particularly when blood pressure is minimally affected, are not known. METHODS AND RESULTS: Using a myocardial infarction model in mice, we demonstrate a tumor necrosis factor-α (TNFα)-dependent enhancement of posterior cerebral artery tone that reduces cerebral blood flow before any overt changes in brain structure and function. TNFα expression is increased in mouse posterior cerebral artery smooth muscle cells at 6 weeks after myocardial infarction. Coordinately, isolated posterior cerebral arteries display augmented myogenic tone, which can be fully reversed in vitro by the competitive TNFα antagonist etanercept. TNFα mediates its effect via a sphingosine-1-phosphate (S1P)-dependent mechanism, requiring sphingosine kinase 1 and the S1P(2) receptor. In vivo, sphingosine kinase 1 deletion prevents and etanercept (2-week treatment initiated 6 weeks after myocardial infarction) reverses the reduction of cerebral blood flow, without improving cardiac function. CONCLUSIONS: Cerebral artery vasoconstriction and decreased cerebral blood flow occur early in an animal model of heart failure; these perturbations are reversed by interrupting TNFα/S1P signaling. This signaling pathway may represent a potential therapeutic target to improve cognitive function in heart failure.

Prolonged Physiological Stress Is Associated With a Lower Rate of Exploratory Learning That Is Compounded by Depression.

BACKGROUND: Stress is a major risk factor for depression, and both are associated with important changes in decision-making patterns. However, decades of research have only weakly connected physiological measurements of stress to the subjective experience of depression. Here, we examined the relationship between prolonged physiological stress, mood, and explore-exploit decision making in a population navigating a dynamic environment under stress: health care workers during the COVID-19 pandemic. METHODS: We measured hair cortisol levels in health care workers who completed symptom surveys and performed an explore-exploit restless-bandit decision-making task; 32 participants were included in the final analysis. Hidden Markov and reinforcement learning models assessed task behavior. RESULTS: Participants with higher hair cortisol exhibited less exploration (r = -0.36, p = .046). Higher cortisol levels predicted less learning during exploration (ß = -0.42, false discovery rate [FDR]-corrected p [pFDR] = .022). Importantly, mood did not independently correlate with cortisol concentration, but rather explained additional variance (ß = 0.46, pFDR = .022) and strengthened the relationship between higher cortisol and lower levels of exploratory learning (ß = -0.47, pFDR = .022) in a joint model. These results were corroborated by a reinforcement learning model, which revealed less learning with higher hair cortisol and low mood (ß = -0.67, pFDR = .002). CONCLUSIONS: These results imply that prolonged physiological stress may limit learning from new information and lead to cognitive rigidity, potentially contributing to burnout. Decision-making measures link subjective mood states to measured physiological stress, suggesting that they should be incorporated into future biomarker studies of mood and stress conditions.

Development and validation of an LC-MS/MS based quantitative assay for marmoset insulin in serum.

Insulin is a peptide hormone that is secreted by the ß cells of the pancreas and is essential to the metabolism of carbohydrates, fats, and proteins in the body. The marmoset insulin peptide is not homologous with human insulin and therefore commonly available assays do not work for this species. Due to the increasing popularity of marmoset research, a simple, specific assay for the quantitation of marmoset insulin is needed. This study aimed to develop and validate a bottom-up proteomic workflow with trypsin digestion and analysis using LC coupled with triple quadrupole mass spectrometry (LC-MS/MS). Marmoset serum proteins were subjected to denaturation, reduction, and enzymatic cleavage to extract a unique, 7 amino acid peptide for quantitation of marmoset insulin. Resolution of the peptide was achieved by LC-MS/MS using electrospray ionization operating in positive mode. Calibration was achieved by aliquot dilution of fully synthetic marmoset insulin tryptic peptide into macaque serum. A stable-isotope labeled (13C, 15N) synthetic marmoset insulin tryptic peptide was used as internal standard. The assay was fully validated according to bioanalytical method validation guidelines for linearity, precision, and dilution linearity using purified marmoset insulin. The limit of detection was 15.49 pmol/L and the limit of quantitation was 140.78 pmol/L. Biological validation was achieved by comparison of samples previously run by radioimmunoassay and measurement of the marmoset insulin response to glucose via an oral glucose tolerance test (OGTT). The physiological range of marmoset insulin was shown to be 84.5 to 1222 pmol/L. In summary, this paper presents a simple, reproducible method to measure marmoset insulin in serum using LC-MS/MS.

Aromatase Inhibition Eliminates Sexual Receptivity Without Enhancing Weight Gain in Ovariectomized Marmoset Monkeys.

Context: Ovarian estradiol supports female sexual behavior and metabolic function. While ovariectomy (OVX) in rodents abolishes sexual behavior and enables obesity, OVX in nonhuman primates decreases, but does not abolish, sexual behavior, and inconsistently alters weight gain. Objective: We hypothesize that extra-ovarian estradiol provides key support for both functions, and to test this idea, we employed aromatase inhibition to eliminate extra-ovarian estradiol biosynthesis and diet-induced obesity to enhance weight gain. Methods: Thirteen adult female marmosets were OVX and received (1) estradiol-containing capsules and daily oral treatments of vehicle (E2; n = 5); empty capsules and daily oral treatments of either (2) vehicle (VEH, 1 mL/kg, n = 4), or (3) letrozole (LET, 1 mg/kg, n = 4). Results: After 7 months, we observed robust sexual receptivity in E2, intermediate frequencies in VEH, and virtually none in LET females (P = .04). By contrast, few rejections of male mounts were observed in E2, intermediate frequencies in VEH, and high frequencies in LET females (P = .04). Receptive head turns were consistently observed in E2, but not in VEH and LET females. LET females, alone, exhibited robust aggressive rejection of males. VEH and LET females demonstrated increased % body weight gain (P = .01). Relative estradiol levels in peripheral serum were E2 >>> VEH > LET, while those in hypothalamus ranked E2 = VEH > LET, confirming inhibition of local hypothalamic estradiol synthesis by letrozole. Conclusion: Our findings provide the first evidence for extra-ovarian estradiol contributing to female sexual behavior in a nonhuman primate, and prompt speculation that extra-ovarian estradiol, and in particular neuroestrogens, may similarly regulate sexual motivation in other primates, including humans.

Testosterone is involved in mediating the effects of prenatal stress in male guinea pig offspring.

Studies in humans have demonstrated a link between stress during pregnancy and altered behaviour and stress reactivity in children. In guinea pigs, we have previously shown that a short period of maternal stress during gestation leads to increased anxiety, elevated basal cortisol levels and decreased testosterone levels in adult males. We hypothesized that restoring testosterone to normal levels in the adult males born to prenatally stressed mothers would reverse the changes in behaviours and endocrine function. We found differences in attention and anxiety-related behaviours and basal stress endocrine activity between the prenatally stressed and control males. Administration of testosterone reversed the behavioural differences in the prenatally stressed offspring. There was, however, little effect of postnatal testosterone administration on stress-related endocrine activity. This study provides new information to begin to address the mechanism underlying the interplay between prenatal stress, gonadal steroids and postnatal behaviours.

Stress and genetics influence hair cortisol in FMR1 premutation carrier mothers of children with fragile X syndrome.

To investigate genetic and environmental influences on cortisol levels, mothers of children with fragile X syndrome (FXS) were studied four times over a 7.5-year period. All participants (n = 84) were carriers of the FMR1 "premutation", a genetic condition associated with impaired HPA axis functioning. Genetic variation was indicated by expansions in the number of CGG (cytosine-guanine-guanine) repeats in the FMR1 gene (67-138 repeats in the present sample). The environmental factor was cumulative exposure to adverse life events during the study period. Cortisol was measured at the beginning of the study via saliva samples and at the end of the study via hair samples; hormone values from these two specimen types were significantly correlated. The interactions between CGG repeat number and adverse life events significantly predicted hair cortisol concentration, including after accounting for the initial salivary cortisol level. For those with fewer CGG repeats, stress exposure was associated with elevated cortisol, the expected response to stress, although women with a higher number of CGGs had a reduced cortisol response to adverse events, which might be related to HPA dysfunction. These results indicate that both exogenous and endogenous factors affect HPA functioning in this population of women.