Advancing mouse models for transplantation research.

Mouse models have been instrumental in understanding mechanisms of transplant rejection and tolerance, but cross-study reproducibility and translation of experimental findings into effective clinical therapies are issues of concern. The Mouse Models in Transplantation symposium gathered scientists and physician-scientists involved in basic and clinical research in transplantation to discuss the strengths and limitations of mouse transplant models and strategies to enhance their utility. Participants recognized that increased procedure standardization, including the use of prespecified, defined endpoints, and statistical power analyses, would benefit the field. They also discussed the generation of new models that incorporate environmental and genetic variables affecting clinical outcomes as potentially important. If implemented, these strategies are expected to improve the reproducibility of mouse studies and increase their translation to clinical trials and, ideally, new Food and Drug Administration-approved drugs.

Prenatal Stress Induces Translational Disruption Associated with Myelination Deficits.

Disruptions to neurodevelopment are known to be linked to behavioral disorders in childhood and into adulthood. The fetal brain is extremely vulnerable to stimuli that alter inhibitory GABAergic pathways and critical myelination processes, programing long-term neurobehavioral disruption. The maturation of the GABAergic system into the major inhibitory pathway in the brain and the development of oligodendrocytes into mature cells capable of producing myelin are integral components of optimal neurodevelopment. The current study aimed to elucidate prenatal stress-induced mechanisms that disrupt these processes and to delineate the role of placental pathways in these adverse outcomes. Pregnant guinea pig dams were exposed to prenatal stress with strobe light exposure for 2 h/day on gestational age (GA) 35, 40, 45, 50, 55, 60, and 65, and groups of fetuses and placentae were collected after the stress exposure on GA40, GA50, GA60, and GA69 (term). Fetal plasma, placental, and brain tissue were collected for allopregnanolone and cortisol quantification with ELISA. Relative mRNA expression of genes of specific pathways of interest was examined with real-time PCR in placental and hippocampal tissue, and myelin basic protein (MBP) was quantified immunohistochemically in the hippocampus and surrounding regions for assessment of mature myelin. Prenatal stress in mid-late gestation resulted in disruptions to the translational machinery responsible for the production of myelin and decreased myelin coverage in the hippocampus and surrounding regions. The male placenta showed an initial protective increase in allopregnanolone concentrations in response to maternal psychosocial stress. The male and female placentae had a sex-dependent increase in neurosteroidogenic enzymes at term following prenatal stress. Independent from exposure to prenatal stress, at gestational day 60 - a critical period for myelin development, the placentae of female fetuses had increased capability of preventing cortisol transfer to the fetus through expression of 11-beta-hydroxysteroid dehydrogenase types 1 and 2. The deficits early in the process of maturation of myelination indicate that the reduced myelination observed at childhood equivalence in previous studies begins in fetal life. This negative programing persists into childhood, potentially due to dysregulation of MBP translation processes. Expression patterns of neurosteroidogenic enzymes in the placenta at term following stress may identify at-risk fetuses that have been exposed to a stressful in utero environment.

A model to predict level of adherence to prehabilitation in older adults with frailty having cancer surgery.

PURPOSE: Preoperative exercise could improve postoperative outcomes for people with frailty; however, little is known about how to predict older people's adherence to exercise before surgery (i.e., prehabilitation) programs. Our objective was to derive and validate a model to predict prehabilitation adherence in older adults living with frailty before cancer surgery. METHODS: This was a nested prospective cohort study of older adults with frailty having cancer surgery who participated in a randomized controlled trial of home-based prehabilitation compared with standard perioperative care. We constructed a multivariable ordinary least squares linear regression model to predict adherence. Covariates were selected a priori based on clinical expertise and systematic review. Optimism was estimated through internal validation using bootstrap resampling. RESULTS: The derivation cohort consisted of 95 participants in the intervention arm of the trial. Percent adherence ranged from 0% to 100%, with a mean (standard deviation) of 61 (34)%. Previous physical activity and age were the only predictors significant at the 5% level. CONCLUSION: A prespecified multivariable model may help to explain a modest degree of variation in prehabilitation adherence in older people with frailty. While this model is an important step toward personalizing prehabilitation support, this study was limited by a small sample size and future research is needed to better understand personalized prediction of prehabilitation adherence in older people with frailty.

RéSUMé: OBJECTIF: L'exercice préopératoire pourrait améliorer les issues postopératoires pour les personnes fragilisées; cependant, on ne sait que peu de choses sur la façon de prédire l'observance des personnes âgées à faire de l'exercice avant leur chirurgie (c.-à-d. à suivre des programmes de préadaptation). Notre objectif était de définir et de valider un modèle pour prédire l'observance de la préadaptation chez les personnes âgées fragilisées avant une chirurgie oncologique. MéTHODE: Il s'agissait d'une étude de cohorte prospective imbriquée auprès de personnes âgées fragilisées subissant une chirurgie oncologique qui ont participé à une étude randomisée contrôlée sur la préadaptation à domicile par rapport aux soins périopératoires standard. Nous avons construit un modèle de régression linéaire des moindres carrés ordinaires multivariés pour prédire l'observance. Les covariables ont été sélectionnées a priori sur la base de notre expertise clinique et d'une revue systématique. L'optimisme a été estimé par validation interne à l'aide d'une méthode de rééchantillonnage type « bootstrap ¼. RéSULTATS: La cohorte de dérivation comprenait 95 participant·es dans le volet intervention de l'étude. Le pourcentage d'observance variait de 0 % à 100 %, avec une moyenne (écart type) de 61 (34) %. L'activité physique antérieure et l'âge étaient les seuls prédicteurs significatifs au seuil de 5 %. CONCLUSION: Un modèle multivarié prédéfini peut aider à expliquer un degré modeste de variation dans l'observance de la préadaptation chez les personnes âgées fragilisées. Bien que ce modèle soit une étape importante vers la personnalisation du soutien à la préadaptation, cette étude a été limitée par un échantillon de petite taille; des recherches futures sont nécessaires pour mieux comprendre la prédiction personnalisée de l'observance de la préadaptation chez les personnes âgées fragilisées.

The Association of Frailty with Outcomes after Cancer Surgery: A Systematic Review and Metaanalysis.

BACKGROUND: Cancer is common in older adults, who often have concurrent frailty. Frailty is a strong predictor of adverse outcomes in surgical patients. Our objective is to systematically review the association of frailty with postoperative mortality and other adverse outcomes in adult patients who have undergone nonemergency cancer surgery. METHODS: After registration (CRD42020171163), we systematically reviewed PubMed, MEDLINE, EMBASE, and CINAHL databases to identify all studies reporting an association between a preoperative frailty measurement and a relevant outcome (primary: all-cause mortality in-hospital or within 30 days of surgery; secondary outcomes: postoperative complications, length of stay, discharge disposition, mortality between 30 days and 1 year, postoperative function, and delirium). All stages of the review were completed in duplicate. Risk of bias was assessed using the Quality in Prognostic Studies (QUIPS) tool. Metaanalysis was used to pool effect estimates using random-effects models. RESULTS: A total of 2877 studies were identified, and 71 were included. Frailty was significantly associated with mortality within 30 days (adjusted odds ratio (OR) 3.02, 95% confidence interval (CI) 1.77-5.15), adverse discharge disposition (adjusted OR 2.14, 95% CI 1.52-3.02), postoperative complications (adjusted OR 2.39, 95% CI 1.64-3.49), longer-term mortality (unadjusted OR 4.32, 95% CI 2.15-8.67), and length of stay (mean difference 2.30, 95% CI 1.10-3.50). The number of studies presenting adequately adjusted estimates was small. Findings may be limited due to publication bias. CONCLUSIONS: In adults having elective cancer surgery, frailty is strongly associated with adverse health outcomes. Preoperative frailty assessment should be considered in prognostication.

Association between frailty and patient outcomes after cancer surgery: a population-based cohort study.

BACKGROUND: Frailty is associated with poor postoperative outcomes, but existing data do not describe frailty's interaction with tumour characteristics at the time of cancer surgery. Our objective was to estimate the association between frailty and long-term survival, and to explore any interaction with tumour stage and grade. METHODS: This was a population-based cohort study conducted using linked provincial health administrative data in Ontario, Canada (2009-20). Using a cancer registry, we identified adults having elective cancer surgery. Frailty was measured using a validated index (range 0-1; higher score=greater frailty). Associations between frailty and long-term postoperative survival (primary outcome) were estimated using proportional hazards regression. Secondary outcomes were length of stay, discharge destination, days alive at home, and healthcare costs. RESULTS: We identified and included 52 012 patients. Mean frailty score was 0.13 (standard deviation 0.07). During follow-up, 19 378 (37.3%) patients died. After adjustment for risk factors, each 10% increase in frailty was associated with a 1.60-fold relative decrease in survival (95% confidence interval: 1.56-1.64). The frailty-survival association was strongest for patients with lower stage and grade cancers. Increased frailty was associated with longer hospital stays (3 days), fewer days alive and at home (42 days yr-1), more frequent discharge to a nursing facility (2.38-fold), and increased healthcare costs ($6048). CONCLUSIONS: Patient frailty is associated with decreased long-term survival after cancer surgery. The association is stronger for early-stage and -grade cancers, which would otherwise have a better survival prognosis.

Prehabilitation in adult patients undergoing surgery: an umbrella review of systematic reviews.

BACKGROUND: The certainty that prehabilitation improves postoperative outcomes is not clear. The objective of this umbrella review (i.e. systematic review of systematic reviews) was to synthesise and evaluate evidence for prehabilitation in improving health, experience, or cost outcomes. METHODS: We performed an umbrella review of prehabilitation systematic reviews. MEDLINE, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, PsycINFO, Joanna Briggs Institute's database, and Web of Science were searched (inception to October 20, 2020). We included all systematic reviews of elective, adult patients undergoing surgery and exposed to a prehabilitation intervention, where health, experience, or cost outcomes were reported. Evidence certainty was assessed using Grading of Recommendations Assessment, Development and Evaluation. Primary syntheses of any prehabilitation were stratified by surgery type. RESULTS: From 1412 titles, 55 systematic reviews were included. For patients with cancer undergoing surgery who participate in any prehabilitation, moderate certainty evidence supports improvements in functional recovery. Low to very low certainty evidence supports reductions in complications (mixed, cardiovascular, and cancer surgery), non-home discharge (orthopaedic surgery), and length of stay (mixed, cardiovascular, and cancer surgery). There was low to very low certainty evidence that exercise prehabilitation reduces the risk of complications, non-home discharge, and length of stay. There was low to very low certainty evidence that nutritional prehabilitation reduces risk of complications, mortality, and length of stay. CONCLUSIONS: Low certainty evidence suggests that prehabilitation may improve postoperative outcomes. Future low risk of bias, randomised trials, synthesised using recommended standards, are required to inform practice. Optimal patient selection, intervention design, and intervention duration must also be determined.

A Systematic Review and Meta-Analysis of Preoperative Frailty Instruments Derived From Electronic Health Data.

BACKGROUND: Frailty is a strong predictor of adverse outcomes in the perioperative period. Given the increasing availability of electronic medical data, we performed a systematic review and meta-analysis with primary objectives of describing available frailty instruments applied to electronic data and synthesizing their prognostic value. Our secondary objectives were to assess the construct validity of frailty instruments that have been applied to perioperative electronic data and the feasibility of electronic frailty assessment. METHODS: Following protocol registration, a peer-reviewed search strategy was applied to Medline, Excerpta Medica dataBASE (EMBASE), Cochrane databases, and the Comprehensive Index to Nursing and Allied Health literature from inception to December 31, 2019. All stages of the review were completed in duplicate. The primary outcome was mortality; secondary outcomes included nonhome discharge, health care costs, and length of stay. Effect estimates adjusted for baseline illness, sex, age, procedure, and urgency were of primary interest; unadjusted and adjusted estimates were pooled using random-effects models where appropriate or narratively synthesized. Risk of bias was assessed. RESULTS: Ninety studies were included; 83 contributed to the meta-analysis. Frailty was defined using 22 different instruments. In adjusted data, frailty identified from electronic data using any instrument was associated with a 3.57-fold increase in the odds of mortality (95% confidence interval [CI], 2.68-4.75), increased odds of institutional discharge (odds ratio [OR], 2.40; 95% CI, 1.99-2.89), and increased costs (ratio of means, 1.54; 95% CI, 1.46-1.63). Most instruments were not multidimensional, head-to-head comparisons were lacking, and no feasibility data were reported. CONCLUSIONS: Frailty status derived from electronic data provides prognostic value as it is associated with adverse outcomes, even after adjustment for typical risk factors. However, future research is required to evaluate multidimensional instruments and their head-to-head performance and to assess their feasibility and clinical impact.

Accuracy and Feasibility of Clinically Applied Frailty Instruments before Surgery: A Systematic Review and Meta-analysis.

BACKGROUND: A barrier to routine preoperative frailty assessment is the large number of frailty instruments described. Previous systematic reviews estimate the association of frailty with outcomes, but none have evaluated outcomes at the individual instrument level or specific to clinical assessment of frailty, which must combine accuracy with feasibility to support clinical practice. METHODS: The authors conducted a preregistered systematic review (CRD42019107551) of studies prospectively applying a frailty instrument in a clinical setting before surgery. Medline, Excerpta Medica Database, Cochrane Library and the Comprehensive Index to Nursing and Allied Health Literature, and Cochrane databases were searched using a peer-reviewed strategy. All stages of the review were completed in duplicate. The primary outcome was mortality and secondary outcomes reflected routinely collected and patient-centered measures; feasibility measures were also collected. Effect estimates were pooled using random-effects models or narratively synthesized. Risk of bias was assessed. RESULTS: Seventy studies were included; 45 contributed to meta-analyses. Frailty was defined using 35 different instruments; five were meta-analyzed, with the Fried Phenotype having the largest number of studies. Most strongly associated with: mortality and nonfavorable discharge was the Clinical Frailty Scale (odds ratio, 4.89; 95% CI, 1.83 to 13.05 and odds ratio, 6.31; 95% CI, 4.00 to 9.94, respectively); complications was associated with the Edmonton Frail Scale (odds ratio, 2.93; 95% CI, 1.52 to 5.65); and delirium was associated with the Frailty Phenotype (odds ratio, 3.79; 95% CI, 1.75 to 8.22). The Clinical Frailty Scale had the highest reported measures of feasibility. CONCLUSIONS: Clinicians should consider accuracy and feasibility when choosing a frailty instrument. Strong evidence in both domains support the Clinical Frailty Scale, while the Fried Phenotype may require a trade-off of accuracy with lower feasibility.

The Association of Frailty With Adverse Outcomes After Multisystem Trauma: A Systematic Review and Meta-analysis.

BACKGROUND: Frailty strongly predicts adverse outcomes in a variety of clinical settings; however, frailty-related trauma outcomes have not been systematically reviewed and quantitatively synthesized. Our objective was to systematically review and meta-analyze the association between frailty and outcomes (mortality-primary; complications, health resource use, and patient experience-secondary) after multisystem trauma. METHODS: After registration (CRD42018104116), we applied a peer-reviewed search strategy to MEDLINE, EMBASE, and Comprehensive Index to Nursing and Allied Health Literature (CINAHL) from inception to May 22, 2019, to identify studies that described: (1) multisystem trauma; (2) participants ≥18 years of age; (3) explicit frailty instrument application; and (4) relevant outcomes. Excluded studies included those that: (1) lacked a comparator group; (2) reported isolated injuries; and (3) reported mixed trauma and nontrauma populations. Criteria were applied independently, in duplicate to title/abstract and full-text articles. Risk of bias was assessed using the Risk of Bias in Nonrandomized Studies-of Interventions (ROBINS-I) tool. Effect measures (adjusted for prespecified confounders) were pooled using random-effects models; otherwise, narrative synthesis was used. RESULTS: Sixteen studies were included that represented 5198 participants; 9.9% of people with frailty died compared to 4.2% of people without frailty. Frailty was associated with increased mortality (adjusted odds ratio [OR], 1.53; 95% confidence interval [CI], 1.37-1.71), complications (adjusted OR, 2.32; 95% CI, 1.72-3.15), and adverse discharge (adjusted OR, 1.78; 95% CI, 1.29-2.45). Patient function, experience, and resource use outcomes were rarely reported. CONCLUSIONS: The presence of frailty is significantly associated with mortality, complications, and adverse discharge disposition after multisystem trauma. This provides important prognostic information to inform discussions with patients and families and highlights the need for trauma system optimization to meet the complex needs of older patients.

Neurosteroid replacement therapy using the allopregnanolone-analogue ganaxolone following preterm birth in male guinea pigs.

BACKGROUND: Children born preterm, especially boys, are at increased risk of developing attention deficit hyperactivity disorder (ADHD) and learning difficulties. We propose that neurosteroid-replacement therapy with ganaxolone (GNX) following preterm birth may mitigate preterm-associated neurodevelopmental impairment. METHODS: Time-mated sows were delivered preterm (d62) or at term (d69). Male preterm pups were randomized to ganaxolone (Prem-GNX; 2.5 mg/kg subcutaneously twice daily until term equivalence), or preterm control (Prem-CON). Surviving male juvenile pups underwent behavioural testing at d25-corrected postnatal age (CPNA). Brain tissue was collected at CPNA28 and mature myelinating oligodendrocytes of the hippocampus and subcortical white matter were quantified by immunostaining of myelin basic protein (MBP). RESULTS: Ganaxolone treatment returned the hyperactive behavioural phenotype of preterm-born juvenile males to a term-born phenotype. Deficits in MBP immunostaining of the preterm hippocampus and subcortical white matter were also ameliorated in animals receiving ganaxolone. However, during the treatment period weight gain was poor, and pups were sedated, ultimately increasing the neonatal mortality rate. CONCLUSION: Ganaxolone improved neurobehavioural outcomes in males suggesting that neonatal treatment may be an option for reducing preterm-associated neurodevelopmental impairment. However, dosing studies are required to reduce the burden of unwanted side effects.

Influence of Plasma Cell Niche Factors on the Recruitment and Maintenance of IRF4hi Plasma Cells and Plasmablasts in Vaccinated, Simian Immunodeficiency Virus-Infected Rhesus Macaques with Low and High Viremia.

In a recent study, we found that protection following simian immunodeficiency virus (SIV) exposure correlated with rectal plasma cell frequency in vaccinated female rhesus macaques. We sought to determine if the same macaques maintained high mucosal plasma cell frequencies postinfection and if this translated to reduced viremia. Although delayed SIV acquisition did not predict subsequent viral control, alterations existed in the distribution of plasma cells and plasmablasts between macaques that exhibited high or low viremia. Flow cytometric analysis of cells from rectal biopsy specimens, bone marrow, and mesenteric lymph nodes of vaccinated infected, unvaccinated infected, and uninfected macaques identified two main IRF4hi subsets of interest: CD138+ plasma cells, and CD138- plasmablasts. In rectal tissue, plasma cell frequency positively correlated with plasma viremia and unvaccinated macaques had increased plasma cells and plasmablasts compared to vaccinated animals. Likewise, plasmablast frequency in the mesenteric lymph node correlated with viremia. However, in bone marrow, plasmablast frequency negatively correlated with viremia. Accordingly, low-viremic macaques had a higher frequency of both bone marrow IRF4hi subsets than did animals with high viremia. Significant reciprocal relationships between rectal and bone marrow plasmablasts suggested that efficient trafficking to the bone marrow as opposed to the rectal mucosa was linked to viral control. mRNA expression analysis of proteins involved in establishment of plasma cell niches in sorted bone marrow and rectal cell populations further supported this model and revealed differential mRNA expression patterns in these tissues. IMPORTANCE: As key antibody producers, plasma cells and plasmablasts are critical components of vaccine-induced immunity to human immunodeficiency virus type 1 (HIV-1) in humans and SIV in the macaque model; however, few have attempted to examine the role of these cells in viral suppression postinfection. Our results suggest that plasmablast trafficking to and retention in the bone marrow play a previously unappreciated role in viral control and contrast the potential contribution of mucosal plasma cells to mediate protection at sites of infection with that of bone marrow plasmablasts and plasma cells to control viremia during chronic infection. Manipulation of niche factors influencing the distribution and maintenance of these critical antibody-secreting cells may serve as potential therapeutic targets to enhance antiviral responses postvaccination and postinfection.

Vaccine Induction of Lymph Node-Resident Simian Immunodeficiency Virus Env-Specific T Follicular Helper Cells in Rhesus Macaques.

Measurement of Ag-specific T follicular helper (TFH) cell activity in rhesus macaques has not previously been reported. Given that rhesus macaques are the animal model of choice for evaluating protective efficacy of HIV/SIV vaccine candidates and that TFH cells play a pivotal role in aiding B cell maturation, quantifying vaccine induction of HIV/SIV-specific TFH cells would greatly benefit vaccine development. In this study, we quantified SIV Env-specific IL-21-producing TFH cells for the first time, to our knowledge, in a nonhuman primate vaccine study. Macaques were primed twice mucosally with adenovirus 5 host range mutant recombinants encoding SIV Env, Rev, Gag, and Nef followed by two i.m. boosts with monomeric SIV gp120 or oligomeric SIV gp140 proteins. At 2 wk after the second protein boost, we obtained lymph node biopsy specimens and quantified the frequency of total and SIV Env-specific IL-21(+) TFH cells and total germinal center B cells, the size and number of germinal centers, and the frequency of SIV-specific Ab-secreting cells in B cell zones. Multiple correlation analyses established the importance of TFH for development of B cell responses in systemic and mucosally localized compartments, including blood, bone marrow, and rectum. Our results suggest that the SIV-specific TFH cells, initially induced by replicating adenovirus-recombinant priming, are long lived. The multiple correlations of SIV Env-specific TFH cells with systemic and mucosal SIV-specific B cell responses indicate that this cell population should be further investigated in HIV vaccine development as a novel correlate of immunity.

Maternal stress in pregnancy affects myelination and neurosteroid regulatory pathways in the guinea pig cerebellum.

Prenatal stress predisposes offspring to behavioral pathologies. These may be attributed to effects on cerebellar neurosteroids and GABAergic inhibitory signaling, which can be linked to hyperactivity disorders. The aims were to determine the effect of prenatal stress on markers of cerebellar development, a key enzyme in neurosteroid synthesis and the expression of GABAA receptor (GABAAR) subunits involved in neurosteroid signaling. We used a model of prenatal stress (strobe light exposure, 2 h on gestational day 50, 55, 60 and 65) in guinea pigs, in which we have characterized anxiety and neophobic behavioral outcomes. The cerebellum and plasma were collected from control and prenatally stressed offspring at term (control fetus: n = 9 male, n = 7 female; stressed fetus: n = 7 male, n = 8 female) and postnatal day (PND) 21 (control: n = 8 male, n = 8 female; stressed: n = 9 male, n = 6 female). We found that term female offspring exposed to prenatal stress showed decreased expression of mature oligodendrocytes (∼40% reduction) and these deficits improved to control levels by PND21. Reactive astrocyte expression was lower (∼40% reduction) following prenatal stress. GABAAR subunit (δ and α6) expression and circulating allopregnanolone concentrations were not affected by prenatal stress. Prenatal stress increased expression (∼150-250% increase) of 5α-reductase type-1 mRNA in the cerebellum, which may be a neuroprotective response to promote GABAergic inhibition and aid in repair. These observations indicate that prenatal stress exposure has marked effects on the development of the cerebellum. These findings suggest cerebellar changes after prenatal stress may contribute to adverse behavioral outcomes after exposure to these stresses.

Long-term effects of preterm birth on behavior and neurosteroid sensitivity in the guinea pig.

BACKGROUND: Ex-preterm children and adolescents are at risk of developing late-onset neurodevelopmental and behavioral disorders. The mechanisms by which this happens are poorly understood and relevant animal models are required. METHODS: Ex-preterm (delivered at 62 d gestation) and term (spontaneously delivered) juvenile guinea pigs underwent behavioral testing at 25 d corrected postnatal age, with tissues collected at 28 d. Neurodevelopmental markers (myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP)) were analyzed in the hippocampus and subcortical white matter by immunohistochemistry. Gamma-aminobutyric acid A (GABAA) receptor subunit mRNA levels were quantified by reverse transcription polymerase chain reaction (RT-PCR), and salivary cortisol measured by enzyme-linked immunosorbent assay. RESULTS: Preterm males travelled greater distances, were mobile for longer, spent more time investigating objects, and approached or interacted with familiar animals more than controls. Myelination and reactive astrocyte coverage was lower in the hippocampus and the subcortical white matter in preterm males. Hippocampal levels of the α5 subunit were also lower in the preterm male brain. Baseline salivary cortisol was higher for preterm males compared to controls. CONCLUSION: We conclude that juvenile ex-preterm male guinea pigs exhibit a hyperactive phenotype and feature impaired neurodevelopment, making this a suitable model for future therapeutic studies.

Prenatal Stress Alters Hippocampal Neuroglia and Increases Anxiety in Childhood.

Prenatal stress has been associated with detrimental outcomes of pregnancy, including altered brain development leading to behavioural pathologies. The neurosteroid allopregnanolone has been implicated in mediating some of these adverse outcomes following prenatal stress due to its potent inhibitory and anxiolytic effects on the brain. The aims of the current study were to characterise key markers for brain development as well as behavioural parameters, adrenocortical responses to handling and possible neurosteroid influences towards outcomes in guinea pig offspring in childhood. Pregnant guinea pig dams were exposed to strobe light for 2 h (9-11 a.m.) on gestational days 50, 55, 60, and 65 and were left to deliver spontaneously at term and care for their litter. Behavioural testing (open-field test, object exploration test) of the offspring was performed at postnatal day 18 (with salivary cortisol and DHEA measured), and brains were collected at post-mortem on day 21. Markers of brain development myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) were assessed via immunohistochemistry, and the neurosteroid allopregnanolone and its rate-limiting enzymes 5α-reductase types 1 and 2 (5αR1/2) were measured in neonatal brains by radioimmunoassay, reverse transcriptase polymerase chain reaction (RT-PCR), and Western blot, respectively. Brain-derived neurotrophic factor protein was measured as a marker of synaptic plasticity, and GABAA receptor subunit expression was also assessed using RT-PCR. Neonates born from mothers stressed during late pregnancy showed a reduction in both MBP (p < 0.01) and GFAP (p < 0.05) expression in the CA1 region of the hippocampus at 21 days of age. Pups of prenatally stressed pregnancies also showed higher levels of anxiety and neophobic behaviours at the equivalent of childhood (p < 0.05). There were no significant changes observed in allopregnanolone levels, 5αR1/2 expression, or GABAA receptor subunit expression in prenatally stressed neonates compared to controls. This study shows alterations in markers of myelination and reactive astrocytes in the hippocampus of offspring exposed to prenatal stress. These changes are also observed in offspring that show increased anxiety behaviours at the equivalent of childhood, which indicates ongoing structural and functional postnatal changes after prenatal stress exposure.

Constructing rich false memories of committing crime.

Memory researchers long have speculated that certain tactics may lead people to recall crimes that never occurred, and thus could potentially lead to false confessions. This is the first study to provide evidence suggesting that full episodic false memories of committing crime can be generated in a controlled experimental setting. With suggestive memory-retrieval techniques, participants were induced to generate criminal and noncriminal emotional false memories, and we compared these false memories with true memories of emotional events. After three interviews, 70% of participants were classified as having false memories of committing a crime (theft, assault, or assault with a weapon) that led to police contact in early adolescence and volunteered a detailed false account. These reported false memories of crime were similar to false memories of noncriminal events and to true memory accounts, having the same kinds of complex descriptive and multisensory components. It appears that in the context of a highly suggestive interview, people can quite readily generate rich false memories of committing crime.

Potential for a cerebellar role in moderate-late preterm associated behavioural disorders.

Preterm birth is known to cause impaired cerebellar development, and this is associated with the development of neurobehavioral disorders. This review aims to identify the mechanisms through which preterm birth impairs cerebellar development and consequently, increases the risk of developing neurobehavioral disorders. The severity of these disorders is directly related to the degree of prematurity, but it is also evident that even late preterm births are at significantly increased risk of developing serious neurobehavioral disorders. Preterm birth is associated with hypoxic events and increased glutamatergic tone within the neonatal brain which contribute to excitotoxic damage. The cerebellum is a dense glutamatergic region which undergoes relatively late neurodevelopment up to and beyond birth. Evidence indicates that the cerebellum forms reciprocal connections to regions important in behaviour regulation such as the limbic system and frontal cortex. Studies using fMRI (functional magnetic resonance Imaging), BOLD (blood oxygen level dependent) response and morphology studies in humans show the cerebellum is often involved in disorders such as attention deficit hyperactivity disorder (ADHD) and anxiety. The vulnerability of the cerebellum to preterm birth insult and its connections to behaviour associated brain regions implicates it in the development of neurobehavioral disorders. Protection against preterm associated insults on the cerebellum may provide a novel avenue through which ADHD and anxiety can be reduced in children born preterm.

Ongoing effects of preterm birth on the dopaminergic and noradrenergic pathways in the frontal cortex and hippocampus of guinea pigs.

Children born preterm have an increased likelihood of developing neurobehavioral disorders such as attention-deficit hyperactivity disorder (ADHD) and anxiety. These disorders have a sex bias, with males having a higher incidence of ADHD, whereas anxiety disorder tends to be more prevalent in females. Both disorders are underpinned by imbalances to key neurotransmitter systems, with dopamine and noradrenaline in particular having major roles in attention regulation and stress modulation. Preterm birth disturbances to neurodevelopment may affect this neurotransmission in a sexually dimorphic manner. Time-mated guinea pig dams were allocated to deliver by preterm induction of labor (gestational age 62 [GA62]) or spontaneously at term (GA69). The resultant offspring were randomized to endpoints as neonates (24 h after term-equivalence age) or juveniles (corrected postnatal day 40, childhood equivalence). Relative mRNA expressions of key dopamine and noradrenaline pathway genes were examined in the frontal cortex and hippocampus and quantified with real-time PCR. Myelin basic protein and neuronal nuclei immunostaining were performed to characterize the impact of preterm birth. Within the frontal cortex, there were persisting reductions in the expression of dopaminergic pathway components that occurred in preterm males only. Conversely, preterm-born females had increased expression of key noradrenergic receptors and a reduction of the noradrenergic transporter within the hippocampus. This study demonstrated that preterm birth results in major changes in dopaminergic and noradrenergic receptor, transporter, and synthesis enzyme gene expression in a sex- and region-based manner that may contribute to the sex differences in susceptibility to neurobehavioral disorders. These findings highlight the need for the development of sex-based treatments for improving these conditions.

Protection from oxygen-glucose deprivation by neurosteroid treatment in primary neurons and oligodendrocytes.

Preterm birth results in an increased risk of neonatal brain injury and neurobehavioural disorders. Despite the seriousness of these adverse outcomes, there are currently no effective therapies to protect the vulnerable developing brain. We propose that neurosteroid replacement therapy may be a novel approach in reducing detrimental neurological outcomes following preterm birth. The use of guinea pig primary neuronal and oligodendrocyte cultures with relevance to late gestation allows insight into the mechanisms behind the effectiveness of these treatments. Primary neuronal and oligodendrocyte cultures were derived from fetal guinea pig frontal cortex brain tissue at gestational age 62 (GA62). Cell cultures were pre-treated with either etifoxine (5 µM) or zuranolone (1 µm) for 24 h prior to insult. Cells were then exposed to either oxygen-glucose deprivation (OGD; 0% O2 and no glucose DMEM; preterm birth insult) or sham (standard cell culture conditions; 25 mM DMEM) for 2 h. Lactate dehydrogenase assay (LDH) was performed following OGD as a measure of cytotoxicity. Relative mRNA expression of key neuronal and oligodendrocyte markers, as well as neuronal receptors and transporters, were quantified using high throughput (Fluidigm) RT-PCR. OGD significantly increased cellular cytotoxicity in both neurons and oligodendrocytes. Additionally, key neuronal marker mRNA expression was reduced following OGD, and oligodendrocytes displayed arrested mRNA expression of key markers of lineage progression. Treatment with etifoxine restored a number of parameters back to control levels, whereas treatment with zuranolone provided a robust improvement in all parameters examined. This study has demonstrated the neuroprotective potential of neurosteroid replacement therapy in a model of hypoxia related to preterm birth. Neuroprotection appears to be mediated through glutamate reduction and increased brain derived neurotrophic factor (BDNF). Future work is warranted in examining these treatments in vivo, with the overall aim to suppress preterm associated brain damage and reduce long term outcomes for affected offspring.

"I don't think that a medication is going to help someone long-term stay off opioids": Treatment and recovery beliefs of rural Vermont family members of people with opioid use disorder.

PURPOSE: Few studies have addressed beliefs about treatment for opioid use disorder (OUD) among family members of people with OUD, particularly in rural communities. This study examined the beliefs of rural family members of people with OUD regarding treatment, including medication for OUD (MOUD), and recovery. METHODS: Semi-structured qualitative interviews were conducted with rural Vermont family members of people with OUD. Twenty family members completed interviews, and data were analyzed using thematic analysis. RESULTS: Four primary themes related to beliefs about OUD treatment emerged: (1) MOUD is another form of addiction or dependency and should be used short-term; (2) essential OUD treatment components include residential and mental health services and a strong support network involving family; (3) readiness as a precursor to OUD treatment initiation; and (4) stigma as an impediment to OUD treatment and other health care services. CONCLUSIONS: Rural family members valued mental health services and residential OUD treatment programs while raising concerns about MOUD and stigma in health care and the community. Several themes (e.g., MOUD as another form of addiction, residential treatment, and treatment readiness) were consistent with prior research. The belief that MOUD use should be short-term was inconsistent with the belief that OUD is a disease. Findings suggest a need for improved education on the effectiveness of MOUD for family members and on stigma for health care providers and community members.