Biology of Sex Differences

Polycystic Ovarian Syndrome (PCOS) is a complex endocrine disorder characterised by hyperandrogenism, oligo- or anovulation, and polycystic ovaries. Endocrine dysfunction in PCOS disrupts both hormonal and neurotransmitter balance, contributing to the psychological distress frequently reported by affected individuals. Although hormonal imbalances have been associated with memory impairments, their specific contribution to cognitive dysfunction in PCOS remains incompletely understood. In this study, we investigated the impact of PCOS on the hippocampus, a brain region critical for memory formation and highly sensitive to sex steroid modulation. A dehydroepiandrosterone (DHEA)-induced PCOS mouse model was employed to assess anxiety-like behaviour, locomotion, and memory. In the open field test (OFT), DHEA-treated mice spent significantly less time in the central zones and travelled a shorter total distance compared with controls, indicating increased anxiety-like behaviour. DHEA treatment also resulted in significantly impaired performance in both the object location test (OLT) and novel object recognition test (NORT), as reflected by a reduced discrimination index. Analysis of hippocampal immediate early gene expression using qRT-PCR revealed altered transcription of memory-related markers, including downregulation of Npas4 and Grin2a, and upregulation of Grin1, Arc, Egr1, and Egr2. Collectively, these findings suggest that elevated androgen levels induce anxiety- and depression-like behaviours and impair cognitive function, including spatial, recognition, and motor learning abilities, in PCOS. Our results further indicate that disrupted cortex-hippocampus communication may underlie these cognitive deficits, underscoring the importance of evaluating memory and cognitive health in women with PCOS to support brain health and overall well-being.

IntroductionAdolescence is a sensitive developmental period during which chronic stress can induce lasting adaptations in corticolimbic circuits involved in stress regulation, cognition, and emotional behavior. We examined the long-term behavioral, endocrine, and molecular consequences of adolescent chronic variable stress (CVS) in male and female rats, focusing on the infralimbic cortex (IL) and basolateral amygdala (BLA) MethodsSprague Dawley rats of both sexes were exposed to CVS during late adolescence and evaluated in adulthood after an extensive recovery period. Behavioral testing included cued fear conditioning and extinction recall, delayed spatial win-shift, novel object recognition, Morris water maze, three-chamber social behavior, and passive avoidance. HPA-axis reactivity to acute restraint was assessed. Targeted qPCR was used to measure stress-related gene expression in the IL and BLA immediately after stress or after a 5-week recovery period ResultsAdolescent CVS did not cause generalized cognitive impairment, but instead produced selective, sex-specific effects. Females had reduced HPA responses to acute stress and mild deficits in delayed spatial win-shift performance, together with long-term IL changes in genes related to adrenergic signaling, plasticity, and GABA clearance. Males showed enhanced Morris water maze probe retention, weaker novel object discrimination, altered passive avoidance with marked inter-individual variability, and enhanced social preference. At the molecular level, males exhibited long-term upregulation of Fkbp5 in IL and downregulation of PACAP, 1D adrenergic receptor, and proenkephalin in BLA, whereas females showed delayed PACAP upregulation in BLA DiscussionAdolescent CVS induces persistent, sex- and region-specific recalibration of corticolimbic function, supporting distinct patterns of vulnerability and resilience, rather than uniform stress pathology.

Introduction The aim of this study was to determine the annual age- and sex-specific prevalence of gender-affirming hormone and puberty blocker use among young people with a gender incongruence (GI) diagnosis in Norway. Methods We integrated data from multiple Norwegian national registers to perform a nationwide register-based study of individuals with known sex assigned at birth who were born in the period 1975-2017 and resident in Norway for all or part of the period 2008-2022. We first calculated the annual age- and sex-specific incidence of GI diagnoses in the population. Then, we calculated the annual age- and sex-specific prevalence of androgen, estrogen, and puberty blocker use among individuals with a GI diagnosis who were under age 25 (for androgens and estrogens) or 18 (for puberty blockers) in the year that they collected the prescription. Results The incidence of GI diagnoses has increased among youth in Norway, most notably since 2015 and with the largest increase among teens assigned female at birth. The prevalence of feminizing and masculinizing hormone therapy has increased in this period as well, but mainly among the oldest teens and young adults. The prevalence of puberty suppression is mostly low but has also increased since 2015, especially in recent years among teens assigned male at birth. Conclusion The prevalence of gender-affirming hormone and puberty blocker use has increased among transgender youth in Norway, concurrently with an increase in the incidence of GI diagnoses.

BackgroundSteroid sulfatase (STS) cleaves sulfate groups from steroid hormones. In humans, STS deficiency is associated with X-linked ichthyosis (a dermatological disorder), neurodevelopmental/mood conditions, and cardiac arrhythmias. Until recently, no single-gene knockout mammalian model existed to investigate these associations; previous work in such a model has been limited to skin phenotypes. MethodsWe generated a novel C57BL/6J mouse model with a deletion in critical exon 2 of Sts. We then examined gene expression and enzyme activity in liver and brain samples of homozygous mice, and assessed the breeding performance and health of male and female deletion-carriers. Subsequently, we compared performance across a range of behavioural paradigms in wildtype and homozygous male and female mice: elevated plus maze, open field, rotarod, spontaneous alternation, and acoustic startle/prepulse inhibition. We also investigated serum steroid hormone levels by liquid chromatography-mass spectrometry and measured heart weights and two morphological indices (bodyweight/tibia length) post mortem. ResultsHomozygous mice almost completely lacked STS expression/activity. Genetically-altered mice exhibited grossly-normal breeding performance, health, and endocrinology. Homozygous mice were more active, and had higher normalised heart weights, than wildtype mice. We also found significant genotype x sex interactions on bodyweight, and on two behavioural measures (potentially reflecting lower anxiety in homozygous males and heightened anxiety in homozygous females). ConclusionsThe Sts-deletion mouse represents an experimentally-tractable model in which to identify and characterise phenotypes associated with STS deficiency. The mechanistic basis of the genotype-phenotype associations described here requires further investigation, and whether such associations translate to humans remains to be tested.

Lesbian, gay, bisexual, transgender, queer, intersex, and asexual (LGBTQIA+) students continue to face violence, exclusion, and barriers at school, including in STEM education. A key underexamined factor in diversity, equity, and inclusion (DEI) efforts is the content of the life science curriculum, which is uniquely positioned to reinforce or refute bioessentialist, binary, and heteronormative biases. Outdated science curricula not only conflict with current scientific evidence but can also perpetuate beliefs that contribute to sexism and LGBTQIA+ marginalization. To address this, we designed four gender and sexual diversity (GSD)-inclusive biology activities, aligned with NGSS standards, and informed by inclusive curriculum frameworks. Using a mixed-methods approach, we studied 127 high school students who participated in two or more inclusive biology activities. Surveys conducted before and after implementation showed significant reductions in essential, binary beliefs about sex and gender, and increases in affirming attitudes toward sex and gender diversity. Interviews conducted after implementation further revealed differences between LGBTQIA+ and straight students conceptualizations of biological sex. Our findings demonstrate that even brief curriculum interventions can shift student attitudes, although we hope future studies will explore the impact of sustained interventions. Updating life science instruction is essential for educational equity and scientific accuracy.

Polycystic ovary syndrome (PCOS) is characterized by reproductive and metabolic disturbances and is associated with increased symptoms of anxiety and depression. Circulating adiponectin, an insulin-sensitizing adipokine, is reduced in women with PCOS, and low adiponectin has been linked to impaired mental health, particularly in females. We investigated whether low serum adiponectin is associated with impaired mental health in women with PCOS and whether adiponectin deficiency exacerbates anxiety-like behaviour in a PCOS-like mouse model. Serum adiponectin was measured in women with (n=179) and without PCOS (n=228), stratified by body mass index (BMI). Health-related quality of life was assessed using the SF-36, generating physical and mental component scores. In parallel, the prenatal androgenization (PNA) PCOS-like mouse model was combined with adiponectin-deficient mice (APNhet) to assess the impact of reduced adiponectin on anxiety-like behaviour with and without prenatal androgen exposure. Women with PCOS had lower total and high molecular weight adiponectin levels compared with controls. Adiponectin positively correlated with mental component scores in women with BMI <30, but not in those with obesity. Free testosterone was inversely correlated with adiponectin. In mice, PNA induced anxiety-like behaviour, however, reduced adiponectin did not exacerbate this phenotype. Although APNhet PNA mice showed 65% lower serum adiponectin levels and reproductive dysfunction, they displayed improved metabolic function. Unlike women with PCOS, adult PNA mice were not hyperandrogenic. These findings suggest that adiponectin is associated with mental health in non-obese women, but reduced adiponectin alone does not induce anxiety-like behaviour in the absence of hyperandrogenism. The differing patterns observed across BMI categories, as well as between the human cohort and experimental data, underscore the complexity of the mechanisms underlying mental health disturbances in PCOS.

BackgroundPolycystic ovary syndrome (PCOS) is a prevalent endocrine disorder and a leading cause of female infertility, with complex genetic, metabolic, and hormonal etiologies. Long non-coding RNAs (lncRNAs) have emerged as important regulators of diverse biological processes, yet their roles in PCOS remain underexplored. Here, we identified and characterized PCOS differentially expressed gene-associated lncRNAs (PDEGAL) with an integrative approach combining expression data, genetic association, and evolutionary analysis. MethodsThirty-three PCOS-associated protein-coding genes were obtained from our prior study, and all their nearby and overlapping lncRNAs were annotated. These candidates were analyzed using UCSC Genome Browser-mapped annotations and datasets, including NCBI RefSeq, GENCODE, GTEx, GWAS SNPs, and conservation, as well as the FANTOM5 cap analysis of gene expression (CAGE) promoter data, to assess their expression, regulatory potential, genetic variant overlaps, and evolutionary conservation. ResultsTwenty-three PDEGALs (18 antisense to, and 5 sharing bidirectional promoters with, known PCOS-associated protein-coding genes) were identified. 17 PDEGALs contained GWAS SNPs with statistically significant disease associations, 9 of which were associated with PCOS-related traits. 5 PDEGALs demonstrated expression in the KGN granulosa cell model of PCOS. Key gene structure element (KGSE) analysis revealed that most PDEGALs are primate-specific. Integrating four criteria--GTEx expression, GWAS SNPs, FANTOM promoterome, and KGSE conservation--highlighted HELLPAR as the only lncRNA fulfilling all four, while five others--PGR-AS1, MTOR-AS1, ENSG00000265179, ENSG00000256218, and LOC105377276--fulfilled three of the four criteria. ConclusionsWe have systematically identified candidate PCOS regulatory lncRNAs with convergent genetic, expression, and evolutionary evidence. These results provide a framework for functional validation and highlight lncRNAs as potential biomarkers and therapeutic targets in PCOS that function by regulating their nearby and overlapping protein-coding genes.

Alternative polyadenylation (APA) is a common posttranscriptional mechanism to regulate gene expression. APA generates mRNAs with varying lengths of 3' UTRs or transcripts that encode distinct protein carboxy-terminal ends. APA is especially important in neurons, where different mRNA variants are often asymmetrically localized to dendrites and axons, and can be locally translated into proteins. Local protein synthesis is crucial for axon guidance, synaptic plasticity, and learning and memory, key processes associated with the development of alcohol use disorder (AUD). We investigated the role of APA in AUD using a mouse model of alcohol dependence characterized by increased voluntary drinking after chronic intermittent ethanol (CIE) exposure. We examined APA during protracted withdrawal from alcohol in three brain regions of male and female mice. Our analyses revealed hundreds of genes undergoing APA in males, but substantially fewer in females, suggesting sex-specific effects of CIE on APA. Notably, male and female mice displayed distinct APA signatures. APA genes were different from differentially expressed genes (DEGs), suggesting that these molecular processes are regulated independently. We also determined that the expression of APA genes was associated with neurons, while DEGs were associated with non-neuronal cells. Many of the APA genes were involved in synaptic integrity, neuroplasticity, and neuronal maintenance, which was consistent with their enrichment in neurons. Our study suggests that APA is a crucial sex- and cell type-specific mechanism in AUD with the potential to influence localized neuronal protein expression during protracted withdrawal and to modify alcohol consumption behavior. HIGHLIGHTSO_LIChronic ethanol exposure in mice results in profound changes of APA genes in brain. C_LIO_LICommonly regulated cleavage and polyadenylation sites and genes were identified in male but not in female mice. C_LIO_LIThere was a minimal overlap between APA and differentially expressed genes (DEGs). C_LIO_LIAPA genes were primarily associated with neurons, whereas DEGs were associated with non-neuronal cells. C_LI

Negative cognitive biases in depression are more pronounced in females than in males. This sex difference emerges during adolescence, a sensitive developmental stage when chronic stress exposure increases the risk of depression in adulthood. The neurobiology linking adolescent stress to sex-specific cognitive bias and resting-state network reorganization in adults remain poorly understood. The study aimed to investigate the longitudinal effects of chronic restraint stress (CRS) during adolescence on cognitive bias and functional connectome in emerging adulthood. 28 Wistar rats (sex-balanced; aged five weeks on arrival) were trained on a judgment bias task with distinct tactile cues signalling differential rewards. Cognitive bias was quantified from responses to ambiguous probe trials. Following training, animals were randomly and equally assigned to CRS or control groups (sex-balanced). Offline resting-state functional MRI scans were conducted at adolescent baseline (pre-CRS) and again in adulthood (post-CRS), followed by probe trials to assess neural and behavioural changes. Following CRS, females showed a greater tendency to shift toward negative bias than males (ratio of odds ratio=3.67). Furthermore, CRS significantly reduced functional connectivity between the left cerebellar-auditory and hypothalamic-thalamic networks only in females. Repeated-measures correlation between cognitive bias and network connectivity were not statistically significant across sex-by-group strata, potentially due to offline imaging and small sample size. However, intra-individual association revealed sex-specific trends, with CRS females showing moderately positive correlations and CRS males exhibiting a weak negative association. The results could inform stratified connectome-based interventions targeting adolescent stress exposures to potentially reduce the risk of adult depression. Six keywords: Resting-State Functional MRI, Chronic Restraint Stress, Judgement Bias, Open Field Test, Sex Differences

Within species, male testosterone is often linked to mating competition and paternal care, suggesting that sex differences in endogenous testosterone values across mammals may covary with broader reproductive strategies. Using a structured literature search, we compiled 63 studies, spanning 31 non-human species and 9 human populations, reporting endogenous, non-experimentally manipulated testosterone values for both adult males and females within the same population and context. From these studies, we calculated male-to-female testosterone ratios, and analysed these data using Bayesian phylogenetic multilevel models. We tested whether testosterone dimorphism was associated with paternal care and sexual size dimorphism while accounting for sampling matrix, assay method, breeding context, and wild versus captive setting. Across non-human mammals, neither paternal care nor sexual size dimorphism (indexing competition) showed a clear association with testosterone ratios, and the same pattern emerged in the primate-only subset. By contrast, sampling matrix was consistently associated with testosterone dimorphism across all analyses, with lower male-to-female ratios in non-blood than in blood-based measures. In primates, testosterone ratios were also lower in captive than in wild populations, although this pattern was not clearly supported in the broader non-human dataset. In the human-only analysis, testosterone ratios did not clearly differ between industrialized and small-scale societies, whereas the matrix effect remained evident. Overall, our results suggest that sampling matrix is a major source of variation even for ratio-based measures, highlighting the need for caution when inferring between-species endocrine differences from studies using different substrates. More broadly, directly comparable, non-experimentally manipulated testosterone data for both sexes remain rare across mammals, limiting comparative inference.

Cannabidiol (CBD) has recently gained significant public acceptance as a safe therapeutic, contributing to increased use during pregnancy. However, little is known about how maternal CBD exposure impacts fetal brain development. Here, we established a preclinical CBD perinatal exposure (CBD-PCE) model to examine the impacts of CBD on astrocyte morphology in the medial prefrontal cortex (mPFC), a brain region critical for working memory and affective behaviors. Astrocytes play critical roles in maintaining ionic/metabolic homeostasis, neurotransmission, and neurovascular coupling in the CNS. They exhibit highly ramified processes with endfeet surrounding synapses, forming tripartite synapses. We quantitatively assessed the impact of CBD-PCE on astrocyte morphology and the composition of tripartite synapses in mPFC using high-resolution three-dimensional (3D) imaging. Our morphometric analyses revealed that CBD-PCE reduced astrocyte density and increased the number of major branches and whole-cell volume in the mPFC of male, but not female, progenies. Using high-magnification 3D analysis, we found that mPFC astrocytes after CBD-PCE exhibited increased neuropil infiltration volume and reduced surface-to-volume ratios in males but not in females. Moreover, the levels of aquaporin-4 (AQP4) and Kir4.1 inwardly rectifying potassium channel, two key components in regulating ionic homeostasis, are elevated on the membranes of male CBD-PCE astrocytes. We also analyzed mPFC tripartite synapses and observed significant increases in thalamocortical tripartite synapse density in both sexes, whereas intracortical excitatory synapses were reduced only in females. Collectively, these findings demonstrate that CBD-PCE induces sex-specific changes in astrocyte morphology and in the composition of tripartite synapses in the mPFC of the progenys brains.

BackgroundHormonal transition phases represent windows of increased neuroplasticity across the female lifespan. In this study, we aim to investigate the brain anatomical architecture of hormonal transition phases by directly comparing menarche, as a period of rising levels of steroid hormones, and menopause, as a time of declining levels. MethodsWe fit linear models on cross-sectional and linear mixed-effect models on longitudinal magnetic resonance imaging (MRI) datasets, to explore the effects of menarche onset (ABCD study data, Ncross-sectional=1274, Nlongitudinal=611) and transition into menopause (UK Biobank data, Ncross-sectional=1614, Nlongitudinal=212) on 66 cortical and 135 subcortical brain volumes, and to identify brain structures with opposing but regional overlapping effects in both periods. Models were adjusted for age and corrected for multiple comparison (P <.05; FDR-corrected). ResultsCross-sectionally, using a between-subject design, 83 brain volumes showed effects of menarche-onset and 17 volumes showed effects of menopause-transition. Of these, seven brain volumes were significantly affected by both transitional periods, showing opposing directional volume changes. Longitudinally, using a within-subject design, 56 brain volumes exhibited menarche effects, of which 46 replicated cross-sectionally. No menopause effect survived correction for multiple comparison, likely due to limited longitudinal sample size. ConclusionOur findings confirm regionally overlapping brain structural alteration between the two hormonal phases - menarche and menopause - showing the hypothesized opposite effect directions. Additionally, our results show the robustness of menarche effects, which converged across cross-sectional and longitudinal study designs. Taken together, our results contribute to a better understanding of hormone related neuroplasticity, emphasizing the importance of not only understanding individual phases, but understanding the overarching patterns across the female reproductive lifespan.

BackgroundChronic alcohol use disorder (AUD) is associated with profound dysregulation of immune function, neuroinflammation, and systemic stress responses, which contribute to both the maintenance of addiction and alcohol-related organ damage. While brain transcriptomic studies have established neuroimmune signaling and synaptic remodeling as central features of AUD, peripheral blood signatures during early withdrawal and recovery remain underexplored. Understanding the dynamic transcriptional changes in peripheral blood accompanying supervised withdrawal therapy is critical for identifying reversible molecular processes versus persistent trait-like alterations. MethodsRNA sequencing (RNA-seq) was performed on peripheral blood from individuals with alcohol use disorder (AUD, n = 100) and healthy controls (n = 74) at baseline and after three weeks of supervised withdrawal therapy. Differentially expressed genes (DEGs) were identified using linear mixed models assessing main effects of group, time, and their interaction. Functional enrichment and co-expression network analyses were performed to identify coordinated biological processes. ResultsAt baseline, more than 1,000 genes were differentially expressed between AUD and control participants, showing robust dysregulation of immune-related pathways. After three weeks of withdrawal, the number of DEGs decreased markedly to 141, indicating partial transcriptomic normalization. Nevertheless, immune dysregulation persisted despite treatment, particularly linked to B cell activation and cell-cell junctions. Interaction analyses (group x time) identified 16 genes whose expression dynamically changed with therapy, highlighting strong enrichment for fatty acid pathways. Co-expression network analysis revealed that baseline modules were enriched for genes associated with secretory granules and immune signaling, while therapy-related co-expression shifts involved coagulation and platelet activation processes. ConclusionsAUD is associated with widespread but partly reversible transcriptomic dysregulation in peripheral blood. These findings support a system-level view of AUD as a disorder of intertwined immune, metabolic, and coagulation biology and suggest that longitudinal blood transcriptomics may help identify both rapidly therapy-responsive and more stable molecular targets for relapse prevention.

Individuals with Fetal Alcohol Spectrum Disorders (FASDs) show reduced subicular volume, and preclinical studies compliment this by demonstrating that third-trimester-equivalent ethanol exposure induced apoptosis in corticolimbic regions, including the subiculum. The subiculum mediates hippocampal-cortical communication critical for long-term memory consolidation. Within the distal dorsal subiculum, a population of bursting neurons uniquely express VGLUT2 and they play a key role in memory processing. We hypothesized that third-trimester-equivalent ethanol exposure would reduce neuronal and VGLUT2+ cell density in the dorsal subiculum and reduce the excitability of bursting neurons, providing a mechanism for long-term memory impairments observed in FASD. To test this, postnatal day (P)7 mice received a subcutaneous injection of ethanol and long-term effects were assessed in adolescence (P35-62). Using transgenic mice with fluorescently labeled VGLUT2+ neurons, and immunohistochemistry we observed a significant reduction in neuronal density in males and an increase in VGLUT2+ cell density in females. Using whole-cell patch clamp electrophysiology, we observed a reduction in action potentials per burst in both sexes. Additionally, females showed reduced overall excitability, and a subset of neurons exhibited a shift to regular spiking. These findings suggest that development ethanol exposure disrupts subicular output by impairing burst firing, potentially weaking hippocampal-cortical communication and contributing to the cognitive deficits associated with FASD. HighlightsO_LIThird-trimester ethanol targets VGLUT2+ neurons in the dorsal subiculum C_LIO_LIEthanol reduced neuronal density in male dorsal subiculum C_LIO_LIEthanol increases VGLUT2+ cell density in females C_LIO_LIEthanol reduces action potential per burst in both sexes C_LIO_LIFemales show reduced excitability and loss of bursting in some cells C_LI

ObjectivesBenign Prostatic Hyperplasia (BPH) is the non-cancerous enlargement of the prostate accompanied by lower urinary tract symptoms, affecting 50% of men by the age of 501,2. Advanced highly symptomatic BPH exhibits large epithelial glandular nodules with microglandular/atypical adenomatous hyperplasia, but how these features form is unknown3. Our lab has reported that the common parasite Toxoplasma gondii can infect the prostate and induce glandular nodule formation in mice3. The objective of this study is to determine if T. gondii exposure in humans correlates to BPH and nodule formation and if it induces urinary dysfunction concurrent in the mouse model. MethodsWe assessed Toxoplasma exposure by serum ELISA in patients with BPH and non-BPH donor controls, and compared seropositivity rates between the groups. We further assessed the histopathology of these patients for the presence of inflammation and epithelial glandular nodule formation and compared Toxoplasma positive and negative samples. We determined voiding function in Toxoplasma-infected mice between 14 and 60 days of infection with void spot with Void Whizzard software. ResultsMen diagnosed with BPH are more likely to be seropositive for Toxoplasma than age-matched undiagnosed donor controls. In addition, BPH patients that are seropositive for Toxoplasma are more likely to exhibit glandular nodule formation with microglandular / adenomous hyperplasia than seronegative BPH patients. In animal studies, Toxoplasma infection results in abnormal void patterns concurrent with microglandular hyperplasia and nodule formation. ConclusionsThese results suggest that Toxoplasma may be contributing to BPH pathology and lower urinary tract dysfunction in both humans and mice, opening new insights into the development of this important disease. The results also serve to further characterize this model of prostatic hyperplasia and define it as a potential urinary dysfunction model.

BackgroundAlcohol use disorder (AUD) is linked to increased neuroinflammation. Alcohol (ethanol) may activate toll-like receptors, which leads to the release of inflammatory molecules that could influence AUD-related behaviors, such as increased alcohol intake. Activation of toll-like receptor 3 (TLR3) by Polyinosinic:polycytidylic acid (Poly(I:C) or PIC) is associated with escalation of alcohol consumption in male, but not female F1 hybrid mice from reciprocal crosses between FVB/NJ (FVB) and C57BL/6J (B6) strains. Little is known about the underlying mechanisms of these sex-specific behavioral effects. In this study, we investigated the effects of TLR3 activation by PIC on temporal profiles of several pro- and anti-inflammatory molecules in the blood and brain of FVB/B6 F1 hybrid male and female mice at multiple time points. We hypothesized that TLR3 - dependent immune profiles would differ between males and females, which may, at least in part, explain the observed differences in drinking behavior. MethodsMale and female FVB/B6 F1 hybrid alcohol-naive mice were injected intraperitoneally with PIC (10 mg/kg) or saline. Blood and perfused brain tissues from the prefrontal cortex (PFC) and striatum were collected at 6-, 24-, and 48-hours post-injection. The expressions of Ccl2, Ccl5, Tnf, Il-6, Il-1{beta}, Ifng, Ifnb1, and Mmp9 genes were analyzed using qPCR. Protein levels of a subset of these molecules and IL-17r/a, IL-4, and IL-10 were measured in striatal samples from the same animals using ELISA. ResultsActivation of TLR3 by PIC triggered time-dependent, sex- and tissue-specific responses in immune genes and their proteins. PIC induced a time-dependent increase in expression of majority of the genes peaking at the 6 hr time point. Temporal immune profiles for pro-inflammatory chemokines, Ccl2 and Ccl5 differed between males and females in the PFC and striatum, suggesting possible sex-specific effects of these molecules on behavior. Protein levels of CCL2, CCL5, and IL-6 increased in the striatum of both sexes and correlated strongly with gene expression, with females showing somewhat higher protein fold changes. MMP-9, a key regulator of blood-brain barrier (BBB) permeability and synaptic plasticity, showed an increase in protein levels, but not mRNA levels in striatum. This pattern suggests altered blood-brain barrier (BBB) permeability, although this would require further investigation. ConclusionOur results revealed distinct TLR3-dependent immune gene and protein expression profiles in blood and brain between males and females and suggested different roles for these molecules in regulating alcohol consumption. We identified CCL2, CCL5 and MMP-9 as target molecules for investigating sex-specific behavior in the immune modulation of alcohol consumption.

BackgroundAn overwhelming body of evidence suggests neuroimmune dysfunction as a key underlying mechanism of FASD-associated adverse CNS outcomes. While few studies have highlighted the lingering effects of prenatal alcohol exposure (PAE) on producing specific immune factors, others suggest a primed neuroimmune state in adulthood, in which a proinflammatory bias is unmasked following subsequent immune activation in later-life. However, the PAE-induced neuroimmune landscape in adulthood remains poorly defined. We hypothesized that PAE induces long-term changes in gene expression linked to neuroimmune function that may be brain region-specific. MethodsUsing long-read next-generation RNA sequencing of brain tissues from a previously established model of a moderate PAE in mice, we compared across six regions: medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), hypothalamus, hippocampus, midbrain, and medulla. A comprehensive bioinformatics analysis investigated PAE-induced changes, dysregulated gene pathways, and transcriptional regulators with a focus on neuroimmune function. ResultsOur data identified at least 60 differentially expressed genes per brain region, many of which were associated with neuroimmune function. Upregulation of multiple proinflammatory factors and pathways was observed, suggesting ongoing baseline neuroimmune activation, potentially involving PXR, TNF, TLR4, the complement pathway, and various cytokine and chemokine signaling. A comparative analysis identified multiple upstream transcriptional regulators across multiple brain regions, including MECP2, TCF7L2, and IL-4. Importantly, this unbiased analysis revealed heterogeneity across brain regions in the activation of canonical immune pathways and highlighted previously unprecedented roles of pathways such as PXR, matrix metalloproteases, and cytokine signaling (e.g., IL-15, IL-27, IL-17) in PAE. ConclusionsPAE creates a unique inflammatory signature in the adult brain, even in the absence of secondary injury, with novel patterns of region-specific changes in genes implicated in glial-immune function. These data identified potential immune targets to elucidate the mechanisms underlying behavioral dysfunction and provide a framework for future therapeutic interventions.

Physical activity offers myriad benefits to health and well-being, in humans and other animals as well. In rodents, voluntary wheel running can attenuate the effects of both physical and social stressors on rodent social behavior. Whether wheel running affects rodent social behaviors per se remains less well understood. We conducted the current study to test whether home cage access to running wheels impacts the social behaviors of adult, group-housed C57BL/6J female mice during same-sex interactions with novel females. Group-housed females were either given continuous home cage running wheel access or a standard paper hut starting at weaning, and as adults, social behaviors were measured during interactions with novel females. In two cohorts, we found that 5 weeks of running wheel access during adolescence reduced the time that subject females spent investigating a novel female and also tended to reduce total ultrasonic vocalizations produced during interactions. These effects were not reversed by a 2-week period of running wheel removal but were recapitulated in a different cohort by 2 weeks of running wheel access in adulthood. Unexpectedly, we found that these effects on female social behavior were not due to wheel running per se, because females raised from weaning with immobile running wheels also showed low rates of social behaviors during same-sex interactions in adulthood. Overall, we find that the presence of a running wheel in the home cage has an enduring inhibitory influence on female social behavior during same-sex interactions, a finding that has implications for the design of studies that include same-sex interactions between female mice.

IntroductionSleep-dependent memory consolidation differs by sex and maybe disrupted by Alzheimers disease (AD) risk. Whether sex moderates associations between apolipoprotein E {varepsilon}4 (APOE {varepsilon}4) status, non-rapid eye movement (NREM) sleep, and memory remains unclear. MethodsEighty cognitively unimpaired older adults completed a word-pair memory task with encoding and immediate testing occurring prior to overnight polysomnography with high-density electroencephalography (hdEEG) and delayed recall occurring after sleep. Sleep-memory associations were examined as a function of sex and APOE {varepsilon}4 status. ResultsIn this sample, a sexxAPOE {varepsilon}4 interaction was associated with overnight memory retention, with female carriers exhibiting less overnight forgetting than female non-carriers and male {varepsilon}4 carriers. NREM sleep differed by sex and APOE {varepsilon}4 status and was associated with memory retention in{varepsilon} 4 carriers. DiscussionThese findings indicate sex-specific, sleep-dependent memory mechanisms associated with genetic AD risk, highlighting sleep as a potential early target for intervention, pending replication in larger samples.

Autism spectrum disorder (ASD) exhibits a profound male biased sex ratio. While numerous genes have been implicated in ASD, the functional basis of this sex difference is unclear. One enticing hypothesis is genome-wide transcriptional regulation through estrogens and androgens. While hormone-mediated transcription is well-studied in reproductive tissues, its role in cortical development is poorly defined. Thus, we profiled androgen (AR) and estrogen (ESR1/ESR2) receptor expression in mid-gestation human fetal (GW16-24) cortex and complementary cortical organoid models, by single-cell RNA-seq. AR was primarily expressed in radial glia and intermediate progenitors while ESR1/ESR2 was more broadly distributed across multiple cell types of the developing cortex, although with the highest expression in radial glia. To study their genetic effects, we exposed iNeurons and cortical organoids to physiological levels of dihydro-testosterone (DHT) and estradiol (E2). DHT consistently up-regulated oxidative metabolism programs enriched in progenitor cells and down-regulated neuronal maturation pathways, while E2 exhibited a much more attenuated effect. The presence of DHT reduced NTRK2 (TrkB) expression, correlating with expression in fetal cortex where NTRK2 had significantly higher expression in progenitor cells of the female cortex, which is also reflected in the increased expression of AR in radial glia. Together, these data indicate that in developing human cortical lineages, sex hormones act as selective, cell-state-dependent modulators that tune metabolic and maturation programs rather than broadly reprogramming the genome. Thus, the effects of variation in transcriptional regulation through estrogens and androgens are likely to be minor, but not absent, in ASD.