Neuroprotection by estradiol

The link between sex hormones and depression over a woman's lifespan (Review)

Major depressive disorder represents one of the most common psychiatric diagnosis, and was ranked by World Health Organization as the third cause of morbidity and mortality worldwide, expecting to become the first cause by 2030. The prevalence of depression is higher in women than in men, once the puberty sets. This may be explained by the hormonal fluctuations, estrogen and progesterone, over a woman's lifespan. Some of the women may experience severe mood symptoms during the luteal phase of the menstrual cycles, known as premenstrual dysphoric disorder. In addition, it has been shown that the use of hormonal contraceptives, especially oral contraceptives (OC), may determine an induced depressive disorder. The risk of induced depressive disorder is even higher in women who start an OC treatment during adolescence, mainly because this is the period when the hormonal milieu is developing. Another important period of hormonal fluctuations is after delivery. It is described such as a hormonal 'withdrawal state' because in a matter of days postpartum, the hormonal levels decrease down to the levels of a non-pregnant woman. It is worth to mention that this extreme decreasing of estrogen and progesterone is not enough in order to develop postpartum depression. It has been suggested that postpartum depression may be a consequence to differential activation of estrogen genes. Fortunately, since 2019, Food and Drug Administration approved the first specific hormonal treatment for postpartum depression, represented by brexanolone. The last period of hormonal changes is the transition to menopause, in which depressive symptoms may be determined by day-to-day hormonal fluctuations. There is a lot more to explore in this field for future research, regarding if there really is a direct link between the levels of estrogen and progesterone and depressive disorder, and also regarding different hormonal therapies.

Androgen effects on mesoprefrontal dopamine systems in the adult male brain

Epidemiological data show that males are more often and/or more severely affected by symptoms of prefrontal cortical dysfunction in schizophrenia, Parkinson's disease and other disorders in which dopamine circuits associated with the prefrontal cortex are dysregulated. This review focuses on research showing that these dopamine circuits are powerfully regulated by androgens. It begins with a brief overview of the sex differences that distinguish prefrontal function in health and prefrontal dysfunction or decline in aging and/or neuropsychiatric disease. This review article then spotlights data from human subjects and animal models that specifically identify androgens as potent modulators of prefrontal cortical operations and of closely related, functionally critical measures of prefrontal dopamine level or tone. Candidate mechanisms by which androgens dynamically control mesoprefrontal dopamine systems and impact prefrontal states of hypo- and hyper-dopaminergia in aging and disease are then considered. This is followed by discussion of a working model that identifies a key locus for androgen modulation of mesoprefrontal dopamine systems as residing within the prefrontal cortex itself. The last sections of this review critically consider the ways in which the organization and regulation of mesoprefrontal dopamine circuits differ in the adult male and female brain, and highlights gaps where more research is needed.

Salivary hormones in depression: the future in diagnosis and treatment

Depression is associated with a significant burden on individuals, families, and communities. It leads to impaired social and occupational functioning, increased disability, decreased quality of life, and higher mortality rates, often due to suicide. A recent estimate from the World Health Organization (WHO) states that over 280 million people of all ages suffer from depression, which equals approximately 3.8% of the world population. Despite effective treatments for mental disorders, a dire treatment gap persists. This treatment gap could be reduced by effective and available diagnostic methods that have the potential to aid in depression diagnosis, stratification of patient subgroups, and treatment monitoring. In this regard, salivary hormones have been studied as potential markers for different types and etiologies of depression due to the convenience of non-invasive sample collection and their correlation with certain aspects of mood and mental health. The literature suggests they can help clinicians assess an individual's stress response, hormonal imbalances, and treatment response, leading to more personalized and effective interventions. In this review, we offer an up-to-date look at all studied salivary hormones associated with depression, including Cortisol, Melatonin, Oxytocin, Serotonin, Dehydroepiandrosterone, Testosterone, Progesterone, and Estradiol.

Sex specific disruptions in Protein Kinase Cγ signaling in a mouse model of Spinocerebellar Ataxia Type 14

Spinocerebellar Ataxia Type 14 (SCA14) is an autosomal dominant neurodegenerative disease caused by mutations in the gene encoding protein kinase C gamma (PKCγ), a Ca 2+ /diacylglycerol (DG)-dependent serine/threonine kinase dominantly expressed in cerebellar Purkinje cells. These mutations impair autoinhibitory constraints to increase the basal activity of the kinase, resulting in deficits in the cerebellum that are not observed upon simple deletion of the gene, and severe ataxia. To better understand the phenotypic impact of aberrant PKCγ signaling in disease pathology, we developed a knock-in murine model of the SCA14 mutation ΔF48 in PKCγ. This fully penetrant mutation is severe in humans and is mechanistically informative as it has high basal activity but is unresponsive to agonist stimulation. Genetic, behavioral, and molecular testing revealed that ΔF48 PKCγ SCA14 mice have ataxia related phenotypes and an altered cerebellar phosphoproteome, effects that are more severe in male mice. Analysis of existing human data reveal that SCA14 has a significantly earlier age of onset for males compared with females. Our data from this clinically relevant mutation suggest that enhanced basal activity of PKCγ is necessary and sufficient to cause ataxia and that treatment strategies to modulate aberrant PKCγ may be particularly beneficial in males.

Summary

New mouse model of Spinocerebellar Ataxia Type 14 containing a clinically relevant mutation in PKCγ identified underlying drivers of the disease and neuroprotection in females.

ATR-FTIR spectroscopy to evaluate serum protein expression in a murine cerebral ischemia model

Stroke is a prevalent vascular disease that causes disability and death worldwide. Molecular techniques have been developed to assess serum concentrations of biomarkers associated with this disease, such as some proteins. ATR-FTIR was proposed as an alternative technique to determine protein expression during the early stages of stroke. Serum samples from sham, ischemic, and ischemic treated with estradiol benzoate (EB; as a neuroprotective agent) male rats were evaluated at 0, 2-, 4-, 6-, 12-, and 24-hours post-ischemia. The analysis was developed in the mid-infrared region but mainly focused on the protein region (1500-1700 cm-1), where it was possible to observe the modulation in the absorbance intensity. The peaks at 1545, 1645, 1635, and 1650 cm-1 associated with amide II, amide I, β-sheets, and α-helixes, respectively, were prominent peaks where protein modulation was observed. The results demonstrate that infrared spectroscopy could be a good alternative technique to determine the modulation of protein expression during stroke events.

Gut microbial 'TNFα-sphingolipids-steroid hormones' axis in children with autism spectrum disorder: an insight from meta-omics analysis

BACKGROUND

Autism spectrum disorder (ASD) is a persistent neurodevelopmental disorder affecting brains of children. Mounting evidences support the associations between gut microbial dysbiosis and ASD, whereas detailed mechanisms are still obscure.

METHODS

Here we probed the potential roles of gut microbiome in ASD using fecal metagenomics and metabolomics.

RESULTS

Children with ASD were found to be associated with augmented serum cytokines milieu, especially TNFα. Metagenomic analysis generated 29 differential species and 18 dysregulated functional pathways such as Bifidobacterium bifidum, Segatella copri, and upregulated 'Sphingolipid metabolism' in children with ASD. Metabolomics revealed steroid hormone dysgenesis in children with ASD with lower abundances of metabolites such as estriol, estradiol and deoxycorticosterone. A three-way association analysis showed positive correlations between TNFα and microbial function potentials such as 'Bacterial toxins' and 'Lysosome', indicating the contribution of microbial dysbiosis to neuroinflammation. TNFα also correlated positively with 'Sphingolipid metabolism', which further showed negative correlations with metabolites estriol and deoxycorticosterone. Such results, in consistent with current findings, revealed the contribution of increased TNFα to upregulated sphingolipid metabolism, which further impaired steroid hormone biosynthesis.

CONCLUSION

Our study proposed the gut microbial 'TNFα-sphingolipids-steroid hormones' axis in children with ASD, which may provide new perspectives for developing gut microbiome-based treatments in the future.

Selective deletion of Tsc1 from mouse cerebellar Purkinje neurons drives sex-specific behavioral impairments linked to autism

There is a striking sex bias in the prevalence and severity of autism spectrum disorder (ASD) with 80% of diagnoses occurring in males. Because the molecular etiology of ASD is likely combinatorial, including interactions across multiple genetic and environmental factors, it is difficult to investigate the physiological mechanisms driving sex-specific differences. Loss of function mutations in TSC1 result in dysregulated mTORC1 signaling and underlie a multi-system disorder known as tuberous sclerosis (TSC). Interestingly, more than 50% of individuals diagnosed with TSC are also diagnosed with ASD, making TSC mutations one of the most prevalent monogenic causes of ASD. Mice harboring targeted deletion of Tsc1 selectively in cerebellar Purkinje neurons, referred to here as Tsc1mut/mut , have multiple ASD-linked behavioral impairments, including deficits in social interactions, motor coordination, and vocalizations. However, these ASD-linked behavioral deficits have only been investigated using male Tsc1mut/mut animals. Here, we used cohorts of male and female Tsc1mut/mut animals to determine if behavioral impairments, previously identified in this model, are similar across sex. Specifically, we measured balance and motor coordination and social interaction behaviors in two age groups across sex. We determined balance and motor coordination deficits are similar in male and female Tsc1mut/mut mice, and that deficits in the firing of Tsc1mut/mut Purkinje neurons located in the cerebellar vermis are also similar across sex. However, impairments in social approach behavior were found to be significantly more severe in Tsc1mut/mut males compared to females. These results indicate the selective deletion of Tsc1 in Purkinje neurons differentially impairs cerebellar circuits based on sex.

Aged mice show a reduction in 5-HT neurons and decreased cellular activation in the dentate gyrus when exposed to acute running

Serotonin (5-HT) is an important neurotransmitter for cognition and neurogenesis in the dentate gyrus (DG), which occurs via movement stimulation such as physical activity. Brain 5-HT function changes secondary to aging require further investigation. We evaluated whether aged animals would present changes in the number of 5-HT neurons in regions such as the dorsal (DRN) and median (MRN) raphe nuclei and possible changes in the rate of cellular activation in the DG in response to acute running, as a reduction in 5-HT neurons could contribute to a decline in neuronal activation in the DG in response to physical activity in aged mice. This study was conducted on adult (3 months old) and aged (19 months old) male and female mice. Immunohistochemistry, microscopic analysis, and treadmill-running tests were also performed. The data revealed that in aged mice, a reduction in the number of 5-HT neurons in the DRN and MRN of male and female mice was observed. The reduction in the DRN was greater in females. Furthermore, aged animals demonstrate a lower rate of c-Fos labeling in the DG when stimulated by physical exercise. These data indicate that aging may be associated with a reduction in the number of 5-HT neurons in the DRN and MRN, which may lead to a decline in 5-HT availability in the target regions, including the DG. The reduced c-Fos expression in the DG after running in aged mice indicates a decreased response to physical activity, which is potentially linked to serotonergic deficits.

Gonadal hormone abnormalities in young patients with first-episode schizophrenia

BACKGROUND

Gonadal hormones have been reported to be involved in the molecular mechanisms of schizophrenia (SCH). However, only a few studies have examined the gonadal hormone dysfunctions in first-episode schizophrenia (FES) patients, in particular in young patients with SCH. This study was designed to investigate the sex differences in gonadal hormones in young and antipsychotic-naïve FES patients.

METHODS

One hundred and sixty-two patients with SCH and 74 healthy controls were recruited, and blood gonadal hormones, including estradiol (E2), follicular-stimulating hormone (FSH), progesterone (PROG), luteinizing hormone (LH), and testosterone (TESTO), were measured in young FES patients and controls.

RESULTS

We found that both male and female young FES patients showed gonadal hormone disturbances at the onset of psychosis. Male patients exhibited a significantly higher rate of abnormal E2 (25.6% vs 3.9%), while female patients had higher rates of abnormal FSH (0% vs 5.3%), PROG (0% vs 21.1%), LH (3.5% vs 17.1%), and TESTO (3.5% vs 13.2%) (all P < .05). Multivariate logistic regression analysis further identified that specific gonadal hormone indices, including E2, LH, and TESTO, were factors associated with sex differences in young FES patients, after controlling for age, smoking status, and body mass index.

CONCLUSIONS

Our study reveals an overall gonadal hormone imbalance in young antipsychotic-naïve FES patients, highlighting sex differences at the onset of psychosis. Our study provides a foundation for further research into the role of gonadal hormones in the pathophysiology of SCH and the potential for personalized medicine approaches based on hormonal balance. Future studies were warranted to explore these differences and their implications for clinical practice to improve the treatment outcomes for individuals suffering from SCH.

Molecular mechanisms of neurofilament alterations and its application in assessing neurodegenerative disorders

Neurofilaments are intermediate filaments present in neurons. These provide structural support and maintain the size and shape of the neurons. Dysregulation, mutation, and aggregation of neurofilaments raise the levels of these proteins in the blood and cerebrospinal fluid (CSF), which are characteristic features of axonal damage and certain rare neurological diseases, such as Giant Axonal Neuropathy and Charcot-Mare-Tooth disease. Understanding the structure, dynamics, and function of neurofilaments has been greatly enhanced by a diverse range of biochemical and preclinical investigations conducted over more than four decades. Recently, there has been a resurgence of interest in post-translational modifications of neurofilaments, such as phosphorylation, aggregation, mutation, oxidation, etc. Over the past twenty years, several rare disorders have been studied from structural alterations of neurofilaments. These disorders are monitored by fluid biomarkers such as neurofilament light chains. Currently, there are many tools, such as Enzyme-Linked Immunosorbent Assay, Electrochemiluminescence Assay, Single-Molecule Array, Western/immunoblotting, etc., in use to assess the neurofilament proteins in Blood and CSF. However, all these techniques utilize expensive, non-specific, or antibody-based methods, which make them unsuitable for routine screening of neurodegenerative disorders. This provides room to search for newer sensitive, cost-effective, point-of-care tools for rapid screening of the disease. For a long time, the molecular mechanisms of neurofilaments have been poorly understood due to insufficient research attempts, and a deeper understanding of them remains elusive. Therefore, this review aims to highlight the available literature on molecular mechanisms of neurofilaments and the function of neurofilaments in axonal transport, axonal conduction, axonal growth, and neurofilament aggregation, respectively. Further, this review discusses the role of neurofilaments as potential biomarkers for the identification of several neurodegenerative diseases in clinical laboratory practice.

Unraveling the complexity of human brain: Structure, function in healthy and disease states

The human brain stands as an intricate organ, embodying a nexus of structure, function, development, and diversity. This review delves into the multifaceted landscape of the brain, spanning its anatomical intricacies, diverse functional capacities, dynamic developmental trajectories, and inherent variability across individuals. The dynamic process of brain development, from early embryonic stages to adulthood, highlights the nuanced changes that occur throughout the lifespan. The brain, a remarkably complex organ, is composed of various anatomical regions, each contributing uniquely to its overall functionality. Through an exploration of neuroanatomy, neurophysiology, and electrophysiology, this review elucidates how different brain structures interact to support a wide array of cognitive processes, sensory perception, motor control, and emotional regulation. Moreover, it addresses the impact of age, sex, and ethnic background on brain structure and function, and gender differences profoundly influence the onset, progression, and manifestation of brain disorders shaped by genetic, hormonal, environmental, and social factors. Delving into the complexities of the human brain, it investigates how variations in anatomical configuration correspond to diverse functional capacities across individuals. Furthermore, it examines the impact of neurodegenerative diseases on the structural and functional integrity of the brain. Specifically, our article explores the pathological processes underlying neurodegenerative diseases, such as Alzheimer's, Parkinson's, and Huntington's diseases, shedding light on the structural alterations and functional impairments that accompany these conditions. We will also explore the current research trends in neurodegenerative diseases and identify the existing gaps in the literature. Overall, this article deepens our understanding of the fundamental principles governing brain structure and function and paves the way for a deeper understanding of individual differences and tailored approaches in neuroscience and clinical practice-additionally, a comprehensive understanding of structural and functional changes that manifest in neurodegenerative diseases.

Selective deletion of Tsc1 from mouse cerebellar Purkinje neurons drives sex-specific behavioral impairments linked to autism

There is a striking sex bias in the prevalence and severity of autism spectrum disorder (ASD) with 80% of diagnoses occurring in males. Because the molecular etiology of ASD is likely combinatorial, including interactions across multiple genetic and environmental factors, it is difficult to investigate the physiological mechanisms driving sex-specific differences. Loss of function mutations in TSC1 result in dysregulated mTORC1 signaling and underlie a multi-system disorder known as tuberous sclerosis (TSC). Interestingly, more than 50% of individuals diagnosed with TSC are also diagnosed with ASD, making TSC mutations one of the most prevalent monogenic causes of ASD. Mice harboring targeted deletion of Tsc1 selectively in cerebellar Purkinje neurons, referred to here as Tsc1 mut/mut , have multiple ASD-linked behavioral impairments, including deficits in social interactions, motor coordination, and vocalizations. However, these ASD-linked behavioral deficits have only been investigated using male Tsc1 mut/mut animals. Here, we used cohorts of male and female Tsc1 mut/mut animals to determine if behavioral impairments, previously identified in this model, are similar across sex. Specifically, we measured balance and motor coordination and social interaction behaviors in two age groups across sex. W e determined balance and motor coordination deficits are similar in male and female Tsc1 mut/mut mice, and that deficits in the firing of Tsc1 mut/mut Purkinje neurons located in the cerebellar vermis are also similar across sex. However, impairments in social approach behavior were found to be significantly more severe in Tsc1 mut/mut males compared to females. These results indicate the selective deletion of Tsc1 in Purkinje neurons differentially impairs cerebellar circuits based on sex.

Increased regional activity of a pro-autophagy pathway in schizophrenia as a contributor to sex differences in the disease pathology

Based on recent genome-wide association studies, it is theorized that altered regulation of autophagy contributes to the pathophysiology of schizophrenia and bipolar disorder. As activity of autophagy-regulatory pathways is controlled by discrete phosphorylation sites on the relevant proteins, phospho-protein profiling is one of the few approaches available for enabling a quantitative assessment of autophagic activity in the brain. Despite this, a comprehensive phospho-protein assessment in the brains of schizophrenia and bipolar disorder subjects is currently lacking. Using this direction, our broad screening identifies an increase in AMP-activated protein kinase (AMPK)-mediated phospho-activation of the pro-autophagy protein beclin-1 solely in the prefrontal cortex of female, but not male, schizophrenia subjects. Using a reverse translational approach, we surprisingly find that this increase in beclin-1 activity facilitates synapse formation and enhances cognition. These findings are interpreted in the context of human studies demonstrating that female schizophrenia subjects have a lower susceptibility to cognitive dysfunction than males.

(S)-S-adenosylmethionine in the treatment of pre-menstrual disorders in adult women: A protocol for an open-label pilot study

Pre-menstrual disorders, including pre-menstrual syndrome and pre-menstrual dysphoric disorder, are highly prevalent disorders in women of reproductive age. Pre-menstrual disorders are associated with debilitating symptoms that onset in the days prior to menses. A complex interplay between hormonal fluctuations, cellular sensitivity, and psychosocial stressors likely underly the pathophysiology of pre-menstrual disorders. Current treatment options include selective serotonin reuptake inhibitors, hormonal therapies, and psychosocial support. There is growing evidence for oestrogen, progesterone, gonadotropin Releasing Hormone analogues and Complementary and Alternative Medicines in treating Pre-menstrual disorders. (S)-S-adenosylmethionine is a complementary and alternative medicine with postulated roles in the treatment of depression, with a rather rapid onset of action and minimal side effect profile. We propose a protocol for investigating the efficacy of (S)-S-adenosylmethionine in the treatment of pre-menstrual disorders. The proposed study is an open label pilot study, that will recruit thirty women between the ages of 18-45 who experience a pre-menstrual disorder. Daily and interval questionnaires will provide a quantification of symptoms across four menstrual cycles (16 weeks). During two consecutive menstrual cycles it is proposed that participants receive oral (S)-S-adenosylmethionine Complex 400 mg three times a day (total daily dose 1200 mg), during the pre-menstrual time-period (14 days prior to menses). Changes in pre-menstrual disorder symptoms between control and treatment cycles will assist in elucidating the clinical efficacy of (S)-S-adenosylmethionine. This study has the potential to support a larger double blinded, placebo controlled randomised control trial and aims to enrich the knowledge surrounding pre-menstrual disorders.

Inferring Drug Set and Identifying the Mechanism of Drugs for PC3

Drug repurposing is a strategy for discovering new applications of existing drugs for use in various diseases. Despite the use of structured networks in drug research, it is still unclear how drugs interact with one another or with genes. Prostate adenocarcinoma is the second leading cause of cancer mortality in the United States, with an estimated incidence of 288,300 new cases and 34,700 deaths in 2023. In our study, we used integrative information from genes, pathways, and drugs for machine learning methods such as clustering, feature selection, and enrichment pathway analysis. We investigated how drugs affect drugs and how drugs affect genes in human pancreatic cancer cell lines that were derived from bone metastases of grade IV prostate cancer. Finally, we identified significant drug interactions within or between clusters, such as estradiol-rosiglitazone, estradiol-diclofenac, troglitazone-rosiglitazone, celecoxib-rofecoxib, celecoxib-diclofenac, and sodium phenylbutyrate-valproic acid.

Brain-derived neurotrophic factor, sex hormones and cognitive decline in male patients with schizophrenia receiving continuous antipsychotic therapy

BACKGROUND

There are systematic differences in clinical features between women and men with schizophrenia (SCZ). The regulation of sex hormones may play a potential role in abnormal neurodevelopment in SCZ. Brain-derived neurotrophic factor (BDNF) and sex hormones have complex interacting actions that contribute to the etiology of SCZ.

AIM

To investigate the influence of BDNF and sex hormones on cognition and clinical symptomatology in chronic antipsychotic-treated male SCZ patients.

METHODS

The serum levels of follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), progesterone, testosterone (T), prolactin (PRL) and BDNF were compared between chronic antipsychotic-treated male (CATM) patients with SCZ (n = 120) and healthy controls (n = 120). The Positive and Negative Syndrome Scale was used to quantify SCZ symptoms, while neuropsychological tests were used to assess cognition. Neuropsychological tests, such as the Digit Cancellation Test (DCT), Semantic Verbal Fluency (SVF), Spatial Span Test (SS), Paced Auditory Serial Addition Test (PASAT), Trail Making Task (TMT-A), and Block Design Test (BDT), were used to assess executive functions (BDT), attention (DCT, TMT-A), memory (SS, PASAT), and verbal proficiency (SVF).

RESULTS

Although E2 levels were significantly lower in the patient group compared to the healthy controls, T, PRL, and LH levels were all significantly higher. Additionally, the analysis revealed that across the entire sample, there were positive correlations between E2 Levels and BDNF levels as well as BDNF levels and the digital cancellation time. In CATM patients with SCZ, a significant correlation between the negative symptoms score and PRL levels was observed.

CONCLUSION

Sex hormones and BDNF levels may also be linked to cognitive function in patients with chronic SCZ.

Transcriptional signatures of the whole-brain voxel-wise resting-state functional network centrality alterations in schizophrenia

Neuroimaging studies have revealed that patients with schizophrenia exhibit disrupted resting-state functional connectivity. However, the inconsistent findings across these studies have hindered our comprehensive understanding of the functional connectivity changes associated with schizophrenia, and the molecular mechanisms associated with these alterations remain largely unclear. A quantitative meta-analysis was first conducted on 21 datasets, involving 1057 patients and 1186 healthy controls, to examine disrupted resting-state functional connectivity in schizophrenia, as measured by whole-brain voxel-wise functional network centrality (FNC). Subsequently, partial least squares regression analysis was employed to investigate the relationship between FNC changes and gene expression profiles obtained from the Allen Human Brain Atlas database. Finally, gene enrichment analysis was performed to unveil the biological significance of the altered FNC-related genes. Compared with healthy controls, patients with schizophrenia show consistently increased FNC in the right inferior parietal cortex extending to the supramarginal gyrus, angular gyrus, bilateral medial prefrontal cortex, and right dorsolateral prefrontal cortex, while decreased FNC in the bilateral insula, bilateral postcentral gyrus, and right inferior temporal gyrus. Meta-regression analysis revealed that increased FNC in the right inferior parietal cortex was positively correlated with clinical score. In addition, these observed functional connectivity changes were found to be spatially associated with the brain-wide expression of specific genes, which were enriched in diverse biological pathways and cell types. These findings highlight the aberrant functional connectivity observed in schizophrenia and its potential molecular underpinnings, providing valuable insights into the neuropathology of dysconnectivity associated with this disorder.

Neurosteroid Receptor Modulators for Treating Traumatic Brain Injury

Traumatic brain injury (TBI) triggers wide-ranging pathology that impacts multiple biochemical and physiological systems, both inside and outside the brain. Functional recovery in patients is impeded by early onset brain edema, acute and chronic inflammation, delayed cell death, and neurovascular disruption. Drug treatments that target these deficits are under active development, but it seems likely that fully effective therapy may require interruption of the multiplicity of TBI-induced pathological processes either by a cocktail of drug treatments or a single pleiotropic drug. The complex and highly interconnected biochemical network embodied by the neurosteroid system offers multiple options for the research and development of pleiotropic drug treatments that may provide benefit for those who have suffered a TBI. This narrative review examines the neurosteroids and their signaling systems and proposes directions for their utility in the next stage of TBI drug research and development.

Investigating the association of breast cancer and stroke: A two-sample Mendelian randomization study

We conducted a two-sample Mendelian randomization (MR) design to evaluate the causal relation between breast cancer and stroke. Genetic variants associated with breast cancer and stroke were both obtained from genome-wide association study summary data. The single nucleotide polymorphisms were selected as instrumental variables. Effect estimates were primarily evaluated using standard inverse variance weighted. Finally, sensitivity analyses were performed for the detection of potential pleiotropy and heterogeneity in the cause-effect evaluation. There was a causal association of ER-positive breast cancer (odds ratio = 0.11, 95% confidence interval: 0.08-0.16, P < .001), and ER-negative breast cancer (odds ratio = 1.04, 95% confidence interval: 1.00-1.07, P = .045) with stroke. MR-egger regression revealed that the cause-effect of ER-positive breast cancer (P < .001) is drove by the directional horizontal pleiotropy, while there was no directional pleiotropy in the cause-effect of ER-negative breast cancer (P = .82). Cochran Q-derived P-value from inverse variance weighted (P = .27) shown that the cause-effect of ER-negative breast cancer on stroke do not need to consider the effect of heterogeneity. In addition, the leave-one-out analysis showed no influential instruments driving the associations, suggesting robust results for all outcomes. The present MR study reveals that ER negative breast cancer increase the risk of stroke.

Gender-specific association of uric acid and survival in sporadic amyotrophic lateral sclerosis patients

OBJECTIVE

To investigate the relationship between serum uric acid (UA) and survival in sporadic amyotrophic lateral sclerosis(sALS) patients.

METHOD

A total of 801 sporadic amyotrophic lateral sclerosis(sALS) patients fulfilled the revised El Escorial criteria were enrolled and followed up in the study. Baseline clinical data and laboratory variables including gender, age, age of onset, site of onset, disease duration, body mass index (BMI), uric acid (UA), creatinine (Cr), and creatine kinase (CK) were collected during enrollment. Multivariate Cox regression models were used to evaluate the survival-related factors after adjustment for confounders.

RESULTS

The serum UA level was significantly lower in female patients than that in male patients (243.5 vs 314.9μmol/L, p<0.001). Gender, BMI, Cr, CK were significantly associated with the level of uric acid according to the linear regression analysis. In the multivariate Cox regression analysis, higher serum UA level (>268.0μmol/L) was an independent protective factor for prolonged survival among female patients (HR=0.69, P=0.042) after adjustment for confounders.

CONCLUSION

The present study provided further support that higher UA was a protective factor for survival in sALS patients, especially in female.

Estrogens, age, and, neonatal stress: panic disorders and novel views on the contribution of non-medullary structures to respiratory control and CO2 responses

CO₂ is a fundamental component of living matter. This chemical signal requires close monitoring to ensure proper match between metabolic production and elimination by lung ventilation. Besides ventilatory adjustments, CO₂ can also trigger innate behavioral and physiological responses associated with fear and escape but the changes in brain CO₂/pH required to induce ventilatory adjustments are generally lower than those evoking fear and escape. However, for patients suffering from panic disorder (PD), the thresholds for CO₂-evoked hyperventilation, fear and escape are reduced and the magnitude of those reactions are excessive. To explain these clinical observations, Klein proposed the false suffocation alarm hypothesis which states that many spontaneous panics occur when the brain's suffocation monitor erroneously signals a lack of useful air, thereby maladaptively triggering an evolved suffocation alarm system. After 30 years of basic and clinical research, it is now well established that anomalies in respiratory control (including the CO₂ sensing system) are key to PD. Here, we explore how a stress-related affective disorder such as PD can disrupt respiratory control. We discuss rodent models of PD as the concepts emerging from this research has influenced our comprehension of the CO₂ chemosensitivity network, especially structure that are not located in the medulla, and how factors such as stress and biological sex modulate its functionality. Thus, elucidating why hormonal fluctuations can lead to excessive responsiveness to CO₂ offers a unique opportunity to gain insights into the neuroendocrine mechanisms regulating this key aspect of respiratory control and the pathophysiology of respiratory manifestations of PD.

Hydroalcoholic extract of Glycyrrhiza glabra root combined with Linum usitatissimum oil as an alternative for hormone replacement therapy in ovariectomized rats

Objective

Plant-derived estrogens (phytoestrogens) with structural similarity to primary female sex hormones could be suitable replacements for sex hormones. Therefore, the effects of the licorice root extract and Linum usitatissimum oil on biochemical and hormonal indices in the serum and uterine stereological changes in ovariectomized rats were evaluated.

Design

In this study, 70 adult female rats were randomly divided into seven groups including 1) control group, 2) sham-operated group, 3) ovariectomized (OVX) group, 4) OVX rats that received 1 mg/kg estradiol for 8 weeks at the day of post-operation, 5) OVX rats which received 2.0 mg/kg body wt Linum usitatissimum oil for 8 weeks at the day of post-operation, 6) OVX rats which received 2.0 mg/kg body wt licorice extract for 8 weeks at the day of post-operation, and 7) OVX rats which received 2.0 mg/kg body wt Linum usitatissimum oil + 2.0 mg/kg body wt licorice extract for 8 weeks at the day of post-operation. After eight weeks, alkaline phosphatase activity, as well as calcium, estradiol, and progesterone concentrations were assessed and tissue samples of the uterus were serologically examined.

Results

The results indicated that after 8 weeks of OVX the alkaline phosphatase activity (Mean = 637.7 IU/L) increased and the calcium (Mean = 7.09 mg/dl), estradiol (5.30 pmol/L), and progesterone (Mean = 3.53 nmol/L) reduced compared to other groups. Moreover, stereological changes in the uterus in ovariectomy groups were seen compared to the other groups. The treatment with Linum usitatissimum oil and licorice extract had a significant therapeutic effect on biochemical factors and stereological changes compared to the ovariectomized group.

Conclusion

The results of this study showed that the combination of Linum usitatissimum oil with licorice extract showed the high potential of hormone replacement therapy in the reduction of OVX complications.

The Purdue Pegboard Test: Normative Data From 1,355 Healthy People From Austria

IMPORTANCE

The Purdue Pegboard Test (PPT) is widely used as a measure of manual dexterity. Declining manual dexterity may predict cognitive decline among elderly people, but normative data for this population are scarce.

OBJECTIVE

To identify demographic and clinical predictors of PPT results in normal middle-aged and elderly Austrian people and to provide norms stratified by significant determinants.

DESIGN

A prospective, community-based cohort study using baseline data of participants from two study panels (1991-1994 and 1999-2003).

SETTING

Monocentric study Participants: 1,355 healthy, randomly selected, community-dwelling people ages 40 to 79 yr.

METHOD

Extensive clinical examination, including completion of the PPT.

OUTCOMES AND MEASURES

The number of pegs placed within a 30-s time limit on four subtests: using the right hand, left hand, both hands, and assembly (within 60 s), respectively. Demographic outcomes were the highest grade achieved.

RESULTS

For all four subtests, increasing age (βs = -0.400 to -0.118, SEs = 0.006 to 0.019, p < .001) and male sex (βs = -1.440 to -0.807, SEs = 0.107 to 0.325, p < .001) was related to worse test results. Among vascular risk factors, diabetes (βs = -1.577 to -0.419, SEs = 0.165 to 0.503, p < .001) was related to worse test results but explained only a small portion (0.7%-1.1%) of the variability in PPT performance.

CONCLUSIONS AND RELEVANCE

We provide age- and sex-specific norms of the PPT for a middle-aged and elderly population. The data represent useful reference values when assessing manual dexterity in older age groups. What This Article Adds: Advancing age and male sex relate to worse performance on the PPT in a community-dwelling cohort without signs and symptoms of neurological disease. Vascular risk factors explain only very little of the variance of test results in our population. Our study adds to the limited age- and sex-specific norms of the PPT among middle-aged and older people.

Non-genomic Effect of Estradiol on the Neurovascular Unit and Possible Involvement in the Cerebral Vascular Accident

Cerebrovascular diseases, such as ischemic cerebral vascular accident (CVA), are responsible for causing high rates of morbidity, mortality, and disability in the population. The neurovascular unit (NVU) during and after ischemic CVA plays crucial roles in cell regulation and preservation, the immune and inflammatory response, and cell and/or tissue survival and repair. Cellular responses to 17β-estradiol (E2) can be triggered by two mechanisms: one called classical or genomic, which is due to the activation of the "classical" nuclear estrogen receptors α (ERα) and β (ERβ), and the non-genomic or rapid mechanism, which is due to the activation of the G protein-coupled estrogen receptor 1 (GPER) that is located in the plasma membrane and some in intracellular membranes, such as in the Golgi apparatus and endoplasmic reticulum. Nuclear receptors can regulate gene expression and cellular functions. On the contrary, activating the GPER by E2 and/or its G-1 agonist triggers several rapid cell signaling pathways. Therefore, E2 or its G-1 agonist, by mediating GPER activation and/or expression, can influence several NVU cell types. Most studies argue that the activation of the GPER may be used as a potential therapeutic target in various pathologies, such as CVA. Thus, with this review, we aimed to summarize the existing literature on the role of GPER mediated by E2 and/or its agonist G-1 in the physiology and pathophysiology of NVU.

Sex differences in neuroimmunoendocrine communication. Involvement on longevity

Endocrine, nervous, and immune systems work coordinately to maintain the global homeostasis of the organism. They show sex differences in their functions that, in turn, contribute to sex differences beyond reproductive function. Females display a better control of the energetic metabolism and improved neuroprotection and have more antioxidant defenses and a better inflammatory status than males, which is associated with a more robust immune response than that of males. These differences are present from the early stages of life, being more relevant in adulthood and influencing the aging trajectory in each sex and may contribute to the different life lifespan between sexes.

Spatial and temporal specificity of neuroestradiol provision in the songbird

Steroid hormones are often synthesized in multiple tissues, affect several different targets, and modulate numerous physiological endpoints. The mechanisms by which this modulation is achieved with temporal and spatial specificity remain unclear. 17β-estradiol for example, is made in several peripheral tissues and in the brain, where it affects a diverse set of behaviors. How is estradiol delivered to the right target, at the right time, and at the right concentration? In the last two decades, we have learned that aromatase (estrogen-synthase) can be induced in astrocytes following damage to the brain and is expressed at central synapses. Both mechanisms of estrogen provision confer spatial and temporal specificity on a lipophilic neurohormone with potential access to all cells and tissues. In this review, I trace the progress in our understanding of astrocytic and synaptic aromatization. I discuss the incidence, regulation, and functions of neuroestradiol provision by aromatization, first in astrocytes and then at synapses. Finally, I focus on a relatively novel hypothesis about the role of neuroestradiol in the orchestration of species-specific behaviors.

Sex-Linked Biology and Gender-Related Research Is Essential to Advancing Hearing Health

There is robust evidence that sex (biological) and gender (behavioral/social) differences influence hearing loss risk and outcomes. These differences are noted for animals and humans-in the occurrence of hearing loss, hearing loss progression, and response to interventions. Nevertheless, many studies have not reported or disaggregated data by sex or gender. This article describes the influence of sex-linked biology (specifically sex-linked hormones) and gender on hearing and hearing interventions, including the role of sex-linked biology and gender in modifying the association between risk factors and hearing loss, and the effects of hearing loss on quality of life and functioning. Most prevalence studies indicate that hearing loss begins earlier and is more common and severe among men than women. Intrinsic sex-linked biological differences in the auditory system may account, in part, for the predominance of hearing loss in males. Sex- and gender-related differences in the effects of noise exposure or cardiovascular disease on the auditory system may help explain some of these differences in the prevalence of hearing loss. Further still, differences in hearing aid use and uptake, and the effects of hearing loss on health may also vary by sex and gender. Recognizing that sex-linked biology and gender are key determinants of hearing health, the present review concludes by emphasizing the importance of a well-developed research platform that proactively measures and assesses sex- and gender-related differences in hearing, including in understudied populations. Such research focus is necessary to advance the field of hearing science and benefit all members of society.

Comparative evaluation of natural neuroprotectives and their combinations on chronic immobilization stress-induced depression in experimental mice

The present study evaluates the potential of neuroprotective phytochemicals-rutin (R), resveratrol (Res), 17β-estradiol (17β-E2), and their different combinations against chronic immobilization stress (CIS)-induced depression-like behaviour in male albino mice. Here, the mice were exposed to stress via immobilization of their four limbs under a restrainer for 6 h daily until 7 days of the induction after 30 min of respective drug treatment in different mice groups. The result found the protective effect of these phytoconstituents and their combinations against CIS-induced depression due to their ability to suppress oxidative stress, restore mitochondria, HPA-axis modulation, neurotransmitter level, stress hormones, and inflammatory markers. Also, the combination drug regimens of these phytoconstituents showed synergistic results in managing the physiological and biochemical features of depression. Thus, these neuroprotective could be utilized well in combination to manage depression-like symptoms during episodic stress. Furthermore, such results could be well justified when administered in polyherbal formulation with these neuroprotective as major components. In addition, an advanced study can be designed at the molecular and epigenetics level using a formulation based on these neuroprotective.

Targeting Estrogen Signaling in the Radiation-induced Neurodegeneration: A Possible Role of Phytoestrogens

Radiation for medical use is a well-established therapeutic method with an excellent prognosis rate for various cancer treatments. Unfortunately, a high dose of radiation therapy comes with its own share of side effects, causing radiation-induced non-specific cellular toxicity; consequently, a large percentage of treated patients suffer from chronic effects during the treatment and even after the post-treatment. Accumulating data evidenced that radiation exposure to the brain can alter the diverse cognitive-related signaling and cause progressive neurodegeneration in patients because of elevated oxidative stress, neuroinflammation, and loss of neurogenesis. Epidemiological studies suggested the beneficial effect of hormonal therapy using estrogen in slowing down the progression of various neuropathologies. Despite its primary function as a sex hormone, estrogen is also renowned for its neuroprotective activity and could manage radiation-induced side effects as it regulates many hallmarks of neurodegenerations. Thus, treatment with estrogen and estrogen-like molecules or modulators, including phytoestrogens, might be a potential approach capable of neuroprotection in radiation-induced brain degeneration. This review summarized the molecular mechanisms of radiation effects and estrogen signaling in the manifestation of neurodegeneration and highlighted the current evidence on the phytoestrogen mediated protective effect against radiationinduced brain injury. This existing knowledge points towards a new area to expand to identify the possible alternative therapy that can be taken with radiation therapy as adjuvants to improve patients' quality of life with compromised cognitive function.

Pre and postnatal exposure to mercury and sexual development in 9-year-old children in Spain: The role of brain-derived neurotrophic factor

Early exposure to mercury has been related to endocrine disruption. Steroid hormones play a crucial role in neural cell migration, differentiation, etc., as well as protecting against several neurotoxic compounds. We investigate the relation between mercury exposure and children's sexual development, and we evaluate the possible influence of different brain-derived neurotrophic factor (BDNF) polymorphisms on this association. Our study sample comprised 412 9-year-old children participating in the INMA cohort (2004-2015). Mercury concentrations were measured at birth (cord blood) and at 4 and 9 years of age (hair). Sexual development was assessed by levels of sex steroid hormones (estradiol and testosterone) in saliva and the Tanner stages of sex development at 9 years (categorized as 1: prepuberty and >1: pubertal onset). Covariates and confounders were collected through questionnaires during pregnancy and childhood. Polymorphisms in the BDNF gene were genotyped in cord blood DNA. Multivariate linear regression analyses were performed between mercury levels and children's sexual development by sex. Effect modification by genetic polymorphisms and fish intake was assessed. We found marginally significant inverse associations between postnatal exposure to mercury (at 9 years) and testosterone levels (β[95%CI] = -0.16[-0.33,0.001], and -0.20[-0.42,0.03], for boys and girls, respectively). Additionally, we found that prenatal mercury was negatively associated with Tanner stage >1 in boys. Finally, we found significant genetic interactions for some single nucleotide polymorphisms in the BDNF gene. In conclusion, pre and postnatal exposure to mercury seems to affect children's sexual development and BDNF may play a role in this association, but further research would be needed.

Surgical Menopause Impairs Retinal Conductivity and Worsens Prognosis in an Acute Model of Rat Optic Neuropathy

Deficiency of estradiol during the menopausal period is an important risk factor for neurodegenerative diseases, including various optic neuropathies. The aim of this study was to evaluate the impact of surgical menopause on the function and survival ratio of RGCs in the rat model of ONC (optic nerve crush). We used eight-week-old female Long Evans rats, divided into two main groups depending on the time between ovariectomy procedure (OVA) and euthanasia (two weeks vs. seven weeks), and subgroups—OVA, OVA + ONC, or ONC. Retinal function was assessed with electroretinography (ERG). RGC loss ratio was evaluated using immunolabelling and counting of RGCs. Seven weeks after OVA, the menopause morphologically affected interneurons but not RGC; however, when the ONC procedure was applied, RGCs appeared to be more susceptible to damage in case of deprivation of estrogens. In our analysis, PhNR (photopic negative responses) were severely diminished in the OVA + ONC group. A deprivation of estrogens in menopause results in accelerated retinal neurodegeneration that firstly involves retinal interneurons. The lack of estrogens increases the susceptibility of RGCs to insults.

Estrogens: Two nuclear receptors, multiple possibilities

Much is known about estrogen action in experimental animal models and in human physiology. This article reviews the mechanisms of estrogen activity in animals and humans and the role of its two receptors α and β in terms of structure and mechanisms of action in various tissues in health and in relationship with human pathologies (e.g., osteoporosis). Recently, the spectrum of clinical pictures of estrogen resistance caused by estrogen receptors gene variants has been widened by our description of a woman with β-receptor defect, which could be added to the already known descriptions of α-receptor defect in women and men and β-receptor defect in men. The essential role of the β-receptor in the development of the gonad stands out. We summarize the clinical pictures due to estrogen resistance in men and women and focus on long-term follow-up of two women, one with α- and the other with β-receptor resistance. Some open questions remain on the complex interactions between the two receptors on bone metabolism and hypothalamus-pituitary-gonadal axis, which need further deepening and research.

Exploring the role of sex differences in Alzheimer's disease pathogenesis in Down syndrome

Women are disproportionately affected by Alzheimer's disease (AD), yet little is known about sex-specific effects on the development of AD in the Down syndrome (DS) population. DS is caused by a full or partial triplication of chromosome 21, which harbors the amyloid precursor protein (APP) gene, among others. The majority of people with DS in their early- to mid-40s will accumulate sufficient amyloid-beta (Aβ) in their brains along with neurofibrillary tangles (NFT) for a neuropathological diagnosis of AD, and the triplication of the APP gene is regarded as the main cause. Studies addressing sex differences with age and impact on dementia in people with DS are inconsistent. However, women with DS experience earlier age of onset of menopause, marked by a drop in estrogen, than women without DS. This review focuses on key sex differences observed with age and AD in people with DS and a discussion of possible underlying mechanisms that could be driving or protecting from AD development in DS. Understanding how biological sex influences the brain will lead to development of dedicated therapeutics and interventions to improve the quality of life for people with DS and AD.

Biological underpinnings of sex differences in neurological disorders

The importance of sex differences in neurological disorders has been increasingly acknowledged in recent clinical and basic research studies, but the complex biology and genetics underlying sex-linked biological heterogeneity and its brain-to-body impact remained incompletely understood. Men and women differ substantially in their susceptibility to certain neurological diseases, in the severity of symptoms, prognosis as well as the nature and efficacy of their response to treatments. The detailed mechanisms underlying these differences, especially at the molecular level, are being addressed in many studies but leave a lot to be further revealed. Here, we provide an overview of recent advances in our understanding of how sex differences in the brain and brain-body signaling contribute to neurological disorders and further present some future prospects entailed in terms of diagnostics and therapeutics.

Tributyltin Exposure Is Associated With Recognition Memory Impairments, Alterations in Estrogen Receptor α Protein Levels, and Oxidative Stress in the Brain of Female Mice

Tributyltin (TBT) is a persistent organometallic pollutant widely used in several agricultural and industrial processes. TBT exposure is associated with various metabolic, reproductive, immune, and cardiovascular abnormalities. However, few studies have evaluated the effects of TBT on behavior. In the present study, we aimed to investigate whether TBT exposure results in oxidative, neuroendocrine, and behavioral alterations. TBT was administered to adult female mice (250, 500, or 750 ng/kg/day or veh for 14 days), and their recognition memory was assessed. We have also evaluated estrogen receptor (ER)α protein expression and oxidative stress (OS) in brain areas related to memory, as well as the correlation between them. A reduction in short- and long-term recognition memory (STM and LTM) performance, as well as in total exploration time was observed in TBT mice. Reduced ERα protein expression was observed in the prefrontal cortex (PFC) and hippocampus of TBT mice, while an increase in TBARS concentration was observed in the PFC of treated animals. Collectively, these data suggest that TBT exposure impairs recognition memory in female mice as a result of, at least in part, its toxicological effects on ERα expression and OS in specific brain areas related to memory.

Micro/nano-plastics cause neurobehavioral toxicity in discus fish (Symphysodon aequifasciatus): Insight from brain-gut-microbiota axis

Numerous studies have investigated neurobehavioral toxicity of microplastics, but no studies have illustrated mechanism via brain-gut axis. Here, juvenile discus fish (Symphysodon aequifasciatus) were exposed for 96 h to microfibers (900 µm, fiber, MFs) or nanoplastics (~88 nm, bead, NPs) with three concentrations (0, 20 and 200 µg/L). Accumulation in fish gut was independent of plastics type and concentration. MFs reduced growth performance while NPs weakened swimming and predatory performance of post-exposed discus. For brain cholinesterase activity, acetylcholinesterase was activated by NPs while NPs/MFs exposure inhibited butyrylcholinesterase. Concentrations of neurotransmitters (acetylcholine, dopamine and γ-aminobutyric acid) increased in brain but decreased in gut after NPs or MFs exposure. For gut microbiota, increased richness under MFs exposure was observed. At phylum level, Proteobacteria proportion was lower in NPs but higher in MFs. Abundance of Clostridia and Fusobacteriia (Bacillus), potentially secreting neurotransmitters, increased in NPs but decreased in MFs. Brain transcriptomics revealed seven upregulated and four downregulated genes concerning neural-activities. Pathways of neuroactive ligand-receptor interaction and serotonergic synapse were enriched in both MFs and NPs, but dopaminergic synapse pathway was enriched only in MFs. These results established a novel mechanism by which microplastics might cause behavioral toxicities via brain-gut-microbiota axis.

Sex Differences in Affective Dysfunction and Alterations in Parvalbumin in Rodent Models of Early Life Adversity

The early life environment markedly influences brain and behavioral development, with adverse experiences associated with increased risk of anxiety and depressive phenotypes, particularly in females. Indeed, early life adversity (ELA) in humans (i.e., caregiver deprivation, maltreatment) and rodents (i.e., maternal separation, resource scarcity) is associated with sex-specific emergence of anxious and depressive behaviors. Although these disorders show clear sex differences in humans, little attention has been paid toward evaluating sex as a biological variable in models of affective dysfunction; however, recent rodent work suggests sex-specific effects. Two widely used rodent models of ELA approximate caregiver deprivation (i.e., maternal separation) and resource scarcity (i.e., limited bedding). While these approaches model aspects of ELA experienced in humans, they span different portions of the pre-weaning developmental period and may therefore differentially contribute to underlying mechanistic risk. This is borne out in the literature, where evidence suggests differences in trajectories of behavior depending on the type of ELA and/or sex; however, the neural underpinning of these differences is not well understood. Because anxiety and depression are thought to involve dysregulation in the balance of excitatory and inhibitory signaling in ELA-vulnerable brain regions (e.g., prefrontal cortex, amygdala, hippocampus), outcomes are likely driven by alterations in local and/or circuit-specific inhibitory activity. The most abundant GABAergic subtypes in the brain, accounting for approximately 40% of inhibitory neurons, contain the calcium-binding protein Parvalbumin (PV). As PV-expressing neurons have perisomatic and proximal dendritic targets on pyramidal neurons, they are well-positioned to regulate excitatory/inhibitory balance. Recent evidence suggests that PV outcomes following ELA are sex, age, and region-specific and may be influenced by the type and timing of ELA. Here, we suggest the possibility of a combined role of PV and sex hormones driving differences in behavioral outcomes associated with affective dysfunction following ELA. This review evaluates the literature across models of ELA to characterize neural (PV) and behavioral (anxiety- and depressive-like) outcomes as a function of sex and age. Additionally, we detail a putative mechanistic role of PV on ELA-related outcomes and discuss evidence suggesting hormone influences on PV expression/function which may help to explain sex differences in ELA outcomes.

Tamoxifen offers long-term neuroprotection after hippocampal silent infarct in male rats

Silent infarcts (SI) are a cerebral small vessel disease characterized by small subcortical infarcts. These occur in the absence of typical ischemia symptoms but are linked to cognitive decline and dementia. While there are no approved treatments for SI, recent results from our laboratory suggest that tamoxifen, a selective estrogen receptor modulator, is a viable candidate. In the present study, we induced SI in the dorsal hippocampal CA1 region of rats and assessed the effects of systemic administration of tamoxifen (5 mg/kg, twice) 21 days after injury on cognitive and pathophysiological measures, including cell loss, apoptosis, gliosis and estrogen receptors (ERs). We found that tamoxifen protected against the SI-induced cognitive dysfunction on the hippocampal-dependent, place recognition task, cell and ER loss, and increased apoptosis and gliosis in the CA1. Exploratory data analyses using a scatterplot matrix and principal component analysis indicated that SI-tamoxifen rats were indistinguishable from sham controls while they differed from SI rats, who were characterized by enhanced cell loss, apoptosis and gliosis, lower ERs, and recognition memory deficit. Supervised machine learning using support vector machine (SVM) determined predictors of progression from the early ischemic state to the dementia-like state. It showed that caspase-3 and ERα in the CA1 and exploration proportion were reliable and accurate predictors of this progression. Importantly, tamoxifen ameliorated SI-induced effects on all three of these variables, providing further evidence for its viability as a candidate treatment for SI and prevention of associated dementia.

Effect of 17β-Estradiol, Progesterone, and Tamoxifen on Neurons Infected with Toxoplasma gondii In Vitro

Toxoplasma gondii (T. gondii) is the causal agent of toxoplasmosis, which produces damage in the central nervous system (CNS). Toxoplasma-CNS interaction is critical for the development of disease symptoms. T. gondii can form cysts in the CNS; however, neurons are more resistant to this infection than astrocytes. The probable mechanism for neuron resistance is a permanent state of neurons in the interface, avoiding the replication of intracellular parasites. Steroids regulate the formation of Toxoplasma cysts in mice brains. 17β-estradiol and progesterone also participate in the control of Toxoplasma infection in glial cells in vitro. The aim of this study was to evaluate the effects of 17β-estradiol, progesterone, and their specific agonists-antagonists on Toxoplasma infection in neurons in vitro. Neurons cultured were pretreated for 48 h with 17β-estradiol or progesterone at 10, 20, 40, 80, or 160 nM/mL or tamoxifen 1 μM/mL plus 17β-estradiol at 10, 20, 40, 80, and 160 nM/mL. In other conditions, the neurons were pretreated during 48 h with 4,4',4″-(4-propyl-[1H] pyrozole-1,3,5-triyl) trisphenol or 23-bis(4-hydroxyphenyl) propionitrile at 1 nM/mL, and mifepristone 1 µM/mL plus progesterone at 10, 20, 40, 80, and 160 nM/mL. Neurons were infected with 5000 tachyzoites of the T. gondii strain RH. The effect of 17β estradiol, progesterone, their agonists, or antagonists on Toxoplasma infection in neurons was evaluated at 24 and 48 h by immunocytochemistry. T. gondii replication was measured with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. 17β-Estradiol alone or plus tamoxifen reduced infected neurons (50%) compared to the control at 48 h. Progesterone plus estradiol decreased the number of intracellular parasites at 48 h of treatment compared to the control (p < 0.001). 4,4',4″-(4-propyl-[1H] pyrozole-1,3,5-triyl) trisphenol and 23-bis(4-hydroxyphenyl) propionitrile reduced infected neurons at 48 h of treatment significantly compared to the control (p < 0.05 and p < 0.001, respectively). The Toxoplasma infection process was decreased by the effect of 17β-estradiol alone or combined with tamoxifen or progesterone in neurons in vitro. These results suggest the essential participation of progesterone and estradiol and their classical receptors in the regulation of T. gondii neuron infection.

Motopsin deficiency imparts partial insensitivity to doxorubicin-induced hippocampal impairments in adult mice

Motopsin is a serine protease that plays a crucial role in synaptic functions. Loss of motopsin function causes severe intellectual disability in humans. In this study, we evaluated the role of motopsin in the neuropathological development of cognitive impairments following chemotherapy, also known as chemobrain. Motopsin knockout (KO) and wild-type (WT) mice were intravenously injected with doxorubicin (Dox) or saline four times every 8 days and were evaluated for open field, novel object recognition, and passive avoidance tests. Parvalbumin-positive neurons in the hippocampus were immunohistochemically analyzed. Dox administration significantly decreased the total distance in the open field test in both WT and motopsin KO mice without affecting the duration spent in the center square. A significant interaction between the genotype and drug treatment was detected in the recognition index (the rate to investigate a novel object) in the novel object recognition test, although Dox treatment did not affect the total investigation time. Additionally, Dox treatment significantly decreased the recognition index in WT mice, whereas it tended to increase the recognition index in motopsin KO mice. Dox treatment did not affect the latency to enter a dark compartment in either WT or motopsin KO mice in the passive avoidance test. Interestingly, Dox treatment increased the parvalbumin-positive neurons in the stratum oriens of the hippocampus CA1 region of only WT mice, not motopsin KO mice. Our data suggest that motopsin deficiency imparted partial insensitivity to Dox-induced hippocampal impairments. Alternatively, motopsin may contribute to the neuropathology of chemobrain.

Brain-Generated 17β-Estradiol Modulates Long-Term Synaptic Plasticity in the Primary Auditory Cortex of Adult Male Rats

Neuron-derived 17β-estradiol (E2) alters synaptic transmission and plasticity in brain regions with endocrine and non-endocrine functions. Investigations into a modulatory role of E2 in synaptic activity and plasticity have mainly focused on the rodent hippocampal formation. In songbirds, E2 is synthesized by auditory forebrain neurons and promotes auditory signal processing and memory for salient acoustic stimuli; however, the modulatory effects of E2 on memory-related synaptic plasticity mechanisms have not been directly examined in the auditory forebrain. We investigated the effects of bidirectional E2 manipulations on synaptic transmission and long-term potentiation (LTP) in the rat primary auditory cortex (A1). Immunohistochemistry revealed widespread neuronal expression of the E2 biosynthetic enzyme aromatase in multiple regions of the rat sensory and association neocortex, including A1. In A1, E2 application reduced the threshold for in vivo LTP induction at layer IV synapses, whereas pharmacological suppression of E2 production by aromatase inhibition abolished LTP induction at layer II/III synapses. In acute A1 slices, glutamate and γ-aminobutyric acid (GABA) receptor-mediated currents were sensitive to E2 manipulations in a layer-specific manner. These findings demonstrate that locally synthesized E2 modulates synaptic transmission and plasticity in A1 and suggest potential mechanisms by which E2 contributes to auditory signal processing and memory.

Pilot Data on the Feasibility And Clinical Outcomes of a Nomegestrol Acetate Oral Contraceptive Pill in Women With Premenstrual Dysphoric Disorder

Background

Up to 80% of reproductive-aged women experience premenstrual symptoms. Premenstrual Dysphoric Disorder (PMDD) is a severe form, affecting 2-5% of women. Combined oral contraceptive pills (COCPs) are used in the treatment of PMDD. Clinical practice suggests that a newer COCP containing nomegestrol acetate (2.5mg) and 17-beta estradiol (1.5mg), may be a suitable treatment for mood symptoms in PMDD.

Materials and Methods

This was a clinical follow-up feasibility study of women who had attended the Monash Alfred Psychiatry research centre, Women's Mental Health Clinic, with a diagnosis of PMDD. 67% of the sample also had concurrent cPTSD, 29% co-morbid anxiety, and 20% depression. They were recommended treatment with nomegestrol acetate/17-beta estradiol. Eligible women were contacted by telephone to answer a questionnaire to assess women's subjective response to nomegestrol acetate/17-beta estradiol, acceptability and the Depression, Anxiety and Stress Scale-21 (DASS-21) after being recommended nomegestrol acetate/17-beta estradiol. The paired-sample t-test was used to determine if there were any statistically significant differences in the DASS-21 scores over the study observation period (before and after taking nomegestrol acetate/17-beta estradiol).

Results

35 (74.5%) women reported a subjective positive mood response to nomegestrol acetate/17-beta estradiol, 31 (63.3%) adhered to the medication, and only 10 (20.4%) women reported side effects as the main reason for discontinuing nomegestrol acetate/17-beta estradiol. There were statistically significant reductions (p<0.05) in the overall DASS-21 scores from before women commenced nomegestrol acetate/17-beta estradiol and after commencement of treatment.

Conclusions

This preliminary study supports the acceptability and effectiveness of nomegestrol acetate/17-beta estradiol as a treatment for mood symptoms in PMDD. Further research, particularly a randomized controlled trial, is required to elucidate the effect of nomegestrol acetate/17-beta estradiol treatment on mood in PMDD.

Neurosteroids: A novel promise for the treatment of stroke and post-stroke complications

Stroke is the primary reason for death and disability worldwide, with few treatment strategies to date. Neurosteroids, which are natural molecules in the brain, have aroused great interest in the field of stroke. Neurosteroids are a kind of steroid that acts on the nervous system, and are synthesized in the mitochondria of neurons or glial cells using cholesterol or other steroidal precursors. Neurosteroids mainly include estrogen, progesterone (PROG), allopregnanolone, dehydroepiandrosterone (DHEA), and vitamin D (VD). Most of the preclinical studies have confirmed that neurosteroids can decrease the risk of stroke, and improve stroke outcomes. In the meantime, neurosteroids have been shown to have a positive therapeutic significance in some post-stroke complications, such as epilepsy, depression, anxiety, cardiac complications, movement disorders, and post-stroke pain. In this review, we report the historical background, modulatory mechanisms of neurosteroids in stroke and post-stroke complications, and emphasize on the application prospect of neurosteroids in stroke therapy.

The Influence of Sex on Upper Extremity Joint Dynamics in Pediatric Manual Wheelchair Users With Spinal Cord Injury

INTRODUCTION

Manual wheelchair propulsion is a physically demanding task associated with upper extremity pain and pathology. Shoulder pain is reported in over 25% of pediatric manual wheelchairs users, and this number rises over the lifespan. Upper extremity biomechanics in adults has been associated with shoulder pain and pathology; however, few studies have investigated upper extremity joint dynamics in children. Furthermore, sex may be a critical factor that is currently unexplored with regard to pediatric wheelchair mobility.

OBJECTIVES

To investigate differences in upper extremity joint dynamics between pediatric male and female manual wheelchair users with spinal cord injury (SCI) during wheelchair propulsion.

METHODS

Novel instrumented wheelchair hand-rims synchronized with optical motion capture were used to acquire upper extremity joint dynamics of 20 pediatric manual wheelchair users with SCI (11 males, 9 females). Thorax, sternoclavicular, acromioclavicular, glenohumeral, elbow, and wrist joint kinematics and kinetics were calculated during wheelchair propulsion. Linear mixed models were used to assess differences between sexes.

RESULTS

Females exhibited significantly greater peak forearm pronation (p = .007), normalized wrist lateral force (p = .03), and normalized elbow posterior force (p = .04) than males. Males exhibited significantly greater peak sternoclavicular joint retraction (p < .001) than females. No significant differences between males and females were observed for the glenohumeral joint (p > .012).

CONCLUSION

This study found significant differences in upper extremity joint dynamics between sexes during manual wheelchair propulsion. Our results underscore the importance of considering sex when evaluating pediatric wheelchair mobility and developing comprehensive wheelchair training interventions for early detection and prevention of upper extremity pain and pathology.

The selective estrogen receptor modulator tamoxifen protects against subtle cognitive decline and early markers of injury 24 h after hippocampal silent infarct in male Sprague-Dawley rats

Silent infarcts (SI) are subcortical cerebral infarcts occurring in the absence of typical ischemia symptoms and are linked to cognitive decline and dementia development. There are no approved treatments for SI. One potential treatment is tamoxifen, a selective estrogen receptor modulator. It is critical to establish whether treatments effectively target the early consequences of SI to avoid progression to complete injury. We induced SI in the dorsal hippocampal CA1 of rats and assessed whether tamoxifen is protective 24 h later against cognitive deficits and injury responses including gliosis, apoptosis, inflammation and changes in estrogen receptors (ERs). SI led to subtle cognitive impairment on the object place task, an effect ameliorated by tamoxifen administration. SI did not lead to detectable hippocampal cell loss but increased apoptosis, astrogliosis, microgliosis and inflammation. Tamoxifen protected against the effects of SI on all measures except microgliosis. SI increased ERα and decreased ERβ in the hippocampus, which were mitigated by tamoxifen. Exploratory data analyses using scatterplot matrices and principal component analysis indicated that SI rats given tamoxifen were indistinguishable from controls. Further, SI rats were significantly different from all other groups, an effect associated with low levels of ERα and increased apoptosis, gliosis, inflammation, ERβ, and time spent with the unmoved object. The results demonstrate that tamoxifen is protective against the early cellular and cognitive consequences of hippocampal SI 24 h after injury. Tamoxifen mitigates apoptosis, gliosis, and inflammation and normalization of ER levels in the CA1, leading to improved cognitive outcomes after hippocampal SI.

The effect of pregnancy on maternal cognition

To determine whether there are differences in measures of cognitive function between second and third trimester pregnant women compared to non-pregnant controls. This prospective study comprised 40 pregnant and 40 non-pregnant women, 20–40 years old, native-Hebrew speakers who were recruited from the outpatient clinics during a period of nearly 2 years. The patients underwent cognitive and affective evaluation. The performance on the three following tests: difficult and total items of Verbal Paired Associates, the Digit Span—forward and the Naming Objects and Fingers test scores were significantly better among non- pregnant women. All the other test results were similar between the two groups, including the depression scores. On multivariate linear regression analysis, after adjusting for age and years of education , Verbal Paired Associates total score (p = 0.04), and Naming Objects and Fingers (p = 0.01) remained significantly associated with pregnancy, but not Digit Span (p = 0.09). Our study demonstrates an impairment in memory among pregnant women. Furthermore language skills, particularly naming, were also impaired, a finding which has not been previously described.

Cytochrome P450-mediated estrogen catabolism therapeutic avenues in epilepsy

Epilepsy is a neuropsychiatric disorder, which does not have any identifiable cause. However, experimental and clinical results have asserted that the sex hormone estrogen level and endocrine system function influence the seizure and epileptic episodes. There are available drugs to control epilepsy, which passes through the metabolism process. Cytochrome P-450 family 1 (CYP1A1) is a heme-containing mono-oxygenase that are induced several folds in most of the tissues and cells contributing to their differential expression, which regulates various metabolic processes upon administration of therapeutics. CYP1A1 gene family has been found to metabolize estrogen, a female sex hormone, which plays a central role in maintaining the health of brain altering the level of estrogen active neuropsychiatric disorder like epilepsy. Hence, in this article, we endeavor to provide an opinion of estrogen, its effects on epilepsy and catamenial epilepsy, their metabolism by CYP1A1 and new way forward to differential diagnosis and clinical management of epilepsy in future.

Network pharmacology identifies IL6 as an important hub and target of tibolone for drug repurposing in traumatic brain injury

Traumatic brain injury (TBI) is characterized by a complex network of signals mediating inflammatory, proliferative and apoptotic processes during its acute and chronic phases. Current therapies mitigate damage and are mainly for palliative care and there are currently no effective therapies for secondary damage. This suggests a need to discover a compound with a greater spectrum of action that can control various pathological aspects of TBI. Here we used a network pharmacology approach to explore the benefits of tibolone, an estrogen and androgen receptor agonist with broader actions in cells, as a possible repurposing drug for TBI therapy. Using different databases we retrieved the targets significantly associated to TBI and tibolone, obtaining 2700 and 652, respectively. The top 10 GO enriched terms were mostly related to cell proliferation, apoptosis and inflammation. Following protein-protein functional analysis, the top connected proteins were related to kinase activity (MAPK1/14/3, AKT1 PIK3R1), apoptosis (TP53, CASP3), growth factors (EGFR), estrogen signalling (ESR1) and inflammation (IL6, TNF), with IL6 as an important signalling hub belonging to the top GO categories. Thus, we identified IL6 as a cellular node which we then validated using molecular mechanics-generalized born surface area (MMGBSA) and docking to explore which tibolone metabolite might interact with this protein. Both 3α and 3β-OH tibolone seemed to bind better to IL6 at important sites responsible for its binding to IL6R. In conclusion, our study demonstrates key hubs involved in TBI pathology which indicates IL6 as a target molecule of tibolone as drug repurposing for TBI therapy.