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.

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.

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

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.

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.

Dopamine signaling plays critical roles in postnatal brain development, yet the molecular consequences of early dopaminergic disturbance remain incompletely understood. Here, we investigated transcriptomic alterations in the prefrontal cortex (PFC) and striatum (STR) of mice subjected to early postnatal dopaminergic disturbance by 6-hydroxydopamine (6-OHDA) treatment. Using bulk RNA sequencing (RNA-seq) and weighted gene co-expression network analysis (WGCNA), we identified 369 differentially expressed genes (DEGs) in the PFC, 493 DEGs in the STR, and 32 co-expression modules with region-specific expression patterns. Functional enrichment analyses showed that PFC DEGs were associated with cortical development, plasma membrane signaling, and transcriptional regulation, whereas STR DEGs were enriched for striatal development, locomotion, extracellular matrix organization, and amphetamine response. Co-expression network analysis further identified module-specific enrichments related to developmental, synaptic, metabolic, immune-related, and transcriptional programs. DEG sets from both regions also overlapped with genes implicated in attention-deficit/hyperactivity disorder (ADHD) and other neuropsychiatric disorders. Together, these findings reveal region-specific cortico-striatal transcriptomic remodeling following early postnatal dopaminergic disturbance and identify molecular programs that may link developmental dopaminergic perturbation to later behavioral phenotypes. HighlightsO_LIEarly dopaminergic disturbance reshapes cortico-striatal transcriptomes C_LIO_LIPFC changes were linked to developmental and transcriptional programs C_LIO_LISTR changes were linked to locomotion and extracellular matrix programs C_LIO_LINetwork analysis revealed region-specific developmental and synaptic programs C_LI

Background: Prenatal substance exposure (PSE) occurs when an individual is exposed to substances in utero. PSEs may have lasting effects on mental health. We tested whether PSEs show threshold, cumulative, or individual substance associations with childhood psychiatric diagnoses. Methods: Clinical variables (demographics, ICD-9/10 diagnoses, PSE history) were extracted from electronic health records from the University of Minnesota Adoption Medicine Clinic. PSEs were identified from caregiver and child-protective-services narratives and/or toxicology (cord tissue/blood, meconium). For each ICD-9/10 diagnostic category, we fit logistic regression models comparing (1) exposure thresholds (0, 1, 2, 3, 4+ exposures), (2) a cumulative exposure count, and (3) individual substances to estimate marginal odds ratios (ORs) with 95% Confidence Intervals (CIs). Results: Psychiatric diagnoses increased with the number of PSEs. Relative to no exposure, odds of an Anxiety Disorder rose from OR 1.47 (95% CI 1.16-1.87) with one exposure to OR 2.03 (1.64-2.52) with >=4 exposures. Higher cumulative exposure scores were associated with Anxiety Disorders (OR 1.28, 1.18-1.38), Behavioral and Emotional Disorders (OR 1.42, 1.31-1.54), Substance Use Disorders (OR 1.52, 1.29-1.79), and Mood Disorders (OR 1.16, 1.04-1.30). Alcohol, tobacco, and marijuana exposures were associated with increased odds of at least one psychiatric diagnosis, and each substance showed at least one significant diagnostic cluster when modeled independently. Conclusion: Increasing numbers of PSEs were associated with higher odds of psychiatric diagnoses, with patterns varying by substance and outcome. These findings motivate research on exposure timing and combinations to support earlier identification and intervention for at-risk children.

Bioengineers strive to recreate in vivo microenvironments in vitro to reduce our use of animal models and provide insights into human biology. While liver models show promise, sex differences in liver biology remain largely neglected in preclinical studies. Despite the 2014 EU mandate for the inclusion of women in clinical trials, decoupling of research data by sex is historically rare, with only 11% of papers disaggregating data by sex. This gap contributes to women being more susceptible to drug-induced liver injury (DILI) and being underserved in drug development, as well as to costly drug attrition levels. Here we present a novel approach to modelling sex differences in vitro. Human induced pluripotent stem cells (iPSCs) from both male (XY) and female (XX) donors, were differentiated into hepatocyte liver spheroids and exposed to in vivo-mimicking levels of testosterone, progesterone, and oestrogen in high-throughput microwell format. We successfully recapitulated sex-specific metabolic profiles and demonstrated significant differences in CYP1A2 and CYP3A4 drug metabolism and gene expression patterns consistent with reported in vivo observations, without compromising cell viability. These findings validate the utility of sex-differentiated microenvironments in early-stage research, offering a pathway to refine animal and clinical trials and improve therapeutic outcomes for all sexes.

Lack of social interaction results in various behavioral abnormalities in rodents, including increased anxiety levels, altered sociability, and impaired cognitive ability. Epigenetic factors regulate gene expression, however, how they contribute to juvenile social isolation (jSI)-induced behavioral alterations remains largely unknown. Here, we focused on the nucleus accumbens (NAc), a critical brain region of the reward system that regulates motivation-related behaviors. We first performed RNA-seq on neuronal nuclei and found alterations in genes related to neuronal function, as well as in transcriptional and epigenetic regulation. Protein-protein interaction (PPI) analysis of differentially expressed genes (DEGs) showed that top key nodes among down-regulated genes include membrane receptors (Ntrk2, Grin3a, and Grik1) and an apoptosis regulator (Bcl2). To further investigate whether jSI-induced gene expression alterations are mediated by histone modifications, we next performed CUT&Tag for four histone modifications (H3K4me1, H3K4me3, H3K27ac, and H3K27me3), and the results implied that epigenetic alterations may also play a role in neuronal function as well as transcriptional regulation. Reanalysis of previously published RNA-seq data on the manipulation of histone modification-associated factors (including Kdm6b, Brd4, and Setd1a) suggested that these enzymes were probably involved in jSI-induced gene expression alterations. Taken together, our comprehensive analysis implies the involvement of histone modification regulation in jSI-related alterations of gene expression in NAc.

The addictive properties of opioids are due in part to these drugs ability to alter ventral tegmental area (VTA) activity via activation of mu opioid receptors (MORs) on local and distal inputs. Prior studies have identified numerous opioid-modulated afferents to the VTA, some of which show differing levels of functional modulation by opioids, but the degree to which this parallels differences in receptor expression is not known. Hence, we used retrograde labeling combined with RNAscope to examine oprm1 mRNA expression in VTA-projecting afferents arising from a variety of distal brain regions. Because opioids are thought to be particularly influential on GABAergic afferents to the VTA, we also examined colocalization of oprm1 with GABAergic markers in VTA-projecting neurons. Interestingly, we found that oprm1 mRNA is present in both GABAergic and non-GABAergic VTA-projecting neurons. However, many (though not all) GABAergic afferents expressed higher levels of oprm1 compared to most non-GABAergic afferents (especially those arising from the cortex). These results complement previous anatomical studies that had examined oprm1 expression in these regions but in a non-quantitative way and without regard to their efferent targets. Our findings encourage future work to examine the functional implications of MOR sensitivity within these afferent pathways.

RationalePrenatal alcohol exposure (PAE) can result in Fetal Alcohol Spectrum Disorder (FASD), which consists of a group of diagnosable medical conditions that can include an increased risk for anxiety disorders and/or alcohol misuse, and sensory issues, such as increased mechanical sensitivity. ObjectiveThis study investigated how a single moderate PAE on gestational day 12 (G12) alters anxiety-like behavior, ethanol (EtOH) intake, and mechanical sensitivity across the lifespan of Sprague Dawley rats. MethodsPregnant dams were exposed to vaporized EtOH or room air (control) for 6 hours (BECs [~]108 mg/dL). Testing in male and female offspring began at three different ages: juveniles ([~]postnatal day (P) 25), adolescents ([~]P45) and adults ([~]P80). ResultsThe greatest PAE effects were observed in adolescent animals, with alterations in anxiety-like behaviors demonstrated in the light-dark box and elevated plus maze. Additionally, adolescent female animals consumed more sweetened EtOH compared to males. However, PAE adolescent animals consuming less sweetened EtOH compared to their counterparts, which was also observed in adult PAE females. Interestingly, this effect is reversed in juvenile and adolescent males when tested with unsweetened EtOH, with juvenile females consuming more EtOH also. Finally, PAE and air animals exhibited increased mechanical sensitivity following post-natal EtOH consumption across all ages. ConclusionThese data demonstrate that there are age- and sex-specific effects of PAE on anxiety-like behaviors, EtOH intake, and mechanical sensitivity that are more distinct in adolescent animals.

Prader-Willi syndrome (PWS) and Schaaf-Yang syndrome (SYS) are neurodevelopmental disorders associated with hypothalamic-pituitary dysregulation. In the pituitary gland, translational control enables rapid peptide hormone production and secretion in response to hypothalamic signals without requiring new mRNA synthesis, yet the mechanisms regulating pituitary translation remain poorly understood. Furthermore, although the PWS-associated gene MAGEL2 has been implicated in neuroendocrine regulation and vesicular trafficking in the hypothalamus, its role in the pituitary gland remains unknown. Initial analysis of previously published pituitary proteomic data revealed enrichment of translation-associated pathways among downregulated proteins in Magel2 KO mice, suggesting translational impairment. Here, we investigated the impact of Magel2 loss on pituitary translatome using polysome profiling and RNA sequencing. We first optimized a polysome profiling workflow for mouse pituitary tissue and established that pooling two to three pituitaries yielded sufficient RNA quality and quantity for downstream analyses. Polysome profiling of WT and Magel2 KO pituitaries revealed no major alterations in global translational activity, as translated and nontranslated fractions were largely unchanged between genotypes. However, transmission electron microscopy revealed a shift toward smaller secretory granule size, indicating altered granule maturation dynamics. To further characterize the pituitary translatome, RNA sequencing was performed on input, monosome, light polysome, and heavy polysome fractions. Clustering analyses identified six distinct translational trajectories across fractions, revealing fraction-specific enrichment of biological pathways. RNAs enriched in heavy polysomes were associated with metabolic and oxidative phosphorylation pathways, whereas monosome-enriched clusters were linked to RNA processing and translation-related functions, suggesting specialized translational regulation within the pituitary. Differential expression analysis demonstrated that translatomic alterations were more pronounced than transcriptomic changes in Magel2 KO pituitaries, with the strongest enrichment observed in heavy polysome fractions. Functional enrichment analyses identified pathways associated with endocrine and metabolic regulation, circadian rhythm, cytoskeleton organization, vesicular trafficking, and RNA regulation, suggesting that translation contributes to pituitary physiological function and patient symptoms. For example, prolactin displayed altered polysome association without changes at the transcript level, consistent with the increased serum prolactin levels observed in Magel2 KO mice and in patients with PWS. Interestingly, the PWS-associated gene Necdin (Ndn) was consistently downregulated across all fractions, which contrasts with previously described compensatory upregulation in the hypothalamus. Together, our findings suggest the involvement of MAGEL2 in pituitary in transcriptional and translational processes and the organization of the secretory pathway and provide the first comprehensive characterization of the mouse pituitary translatome. This work provides new insights into the mechanisms underlying neuroendocrine dysfunction in PWS and SYS and establishes a resource for future studies of translational regulation in neuroendocrine disease.

RATIONALEEnvironmental enrichment (EE) paradigms in rodents have long demonstrated that enhanced sensory, cognitive, social, and motor stimulation positively impacts brain function, improving learning, memory, and neuroplasticity. These effects have significant implications for understanding cognitive development and mitigating cognitive decline and brain aging. While numerous transcriptomic studies have explored EE-induced molecular changes, a unified view of the genes and pathways consistently modulated remains lacking. METHODSTo address this gap, we performed a systematic review and meta-analysis. We conducted a comprehensive PubMed search for all studies published up to February 2025 that matched all the following inclusion criteria: (1) employed EE paradigms; (2) were conducted on rodents; (3) utilized genome-wide transcriptomic methods; (4) examined brain regions or neuronal populations. The 323 retrieved articles were manually screened for relevance to the study aims and data availability. Datasets from 20 eligible RNA-seq reports were reprocessed using a unified analysis pipeline and subjected to a meta-analysis with three complementary statistical methods. RESULTSDespite considerable heterogeneity across studies, our integrative analysis identified consistent gene expression signatures linked to synaptic function, plasticity and their transcriptional regulation. These molecular insights advance our understanding of how EE impacts on neuronal and behavioural outcomes, and may inform therapeutic strategies aimed at replicating or enhancing EE benefits. To promote open science and foster further research, we developed an accessible web application, mEEtaBrain, that enables the neuroscience community to navigate and interrogate our meta-analysis results.

BackgroundDisturbance of circadian rhythms is a hallmark of substance use disorders, with depressant drugs often causing soporific effects such as reduced sleep latency. The suprachiasmatic nucleus (SCN) of the hypothalamus is the central circadian pacemaker in mammals, regulating daily rhythms in physiology and behavior. However, the cellular mechanisms through which depressants alter SCN function remain poorly defined. MethodsWe used whole-cell patch clamp electrophysiology in acute brain slices to examine how alcohol and opioids modulate excitatory glutamatergic transmission onto SCN neurons. Ethanol effects were examined both acutely and following chronic exposure paradigms. Optogenetic stimulation was used to activate either RHT input or -opioid receptor-expressing (MOR) terminals, and MOR agonists were used to assess opioid-mediated effects on synaptic transmission. ResultsWe show that acute application of ethanol paradoxically enhances SCN firing rates. In contrast, chronic alcohol exposure reduces glutamatergic drive. We also found that activating MOR+ terminals produced bidirectional modulation of SCN firing and that MOR+ inputs formed functional glutamatergic synapses onto SCN neurons. Notably, this transmission could be suppressed by the MOR agonists DAMGO and fentanyl. ConclusionsTogether, these findings reveal that both alcohol and opioids modulate glutamatergic input to the SCN. This work establishes the SCN as a novel target of depressant substances and highlights glutamatergic transmission as a key point of vulnerability in circadian dysregulation associated with substance use.

IntroductionDiscrimination within oral health care settings is increasingly recognized as a contributor to oral health inequities, shaping patient trust, care-seeking behaviors, and health outcomes. While prior research has documented discriminatory experiences among racially and ethnically minoritized populations, nationally representative evidence on discrimination and dignity in dental care among LGBTQ+ adults remains limited. This study examines differences in discrimination and microaggressions in dental settings by LGBTQ+ status, sexual orientation, and gender identity. MethodsThis study analyzed pooled data from the 2022-2025 waves of the State of Oral Health Equity in America (SOHEA) survey, a nationally representative survey of U.S. adults aged 18 and older. Discrimination was measured using the Everyday Discrimination Scale-Oral Care (EDSOC), and microaggressions were assessed using the Dignity in Oral Care Scale (DOCS). Descriptive and bivariate analyses compared mean scores across identity groups. Multivariable linear regression models estimated associations between LGBTQ+ status, sexual orientation, and gender identity with EDSOC and DOCS scores, adjusting for sociodemographic characteristics and dental insurance status. Analyses focused on group differences and associations and were conducted without applying survey weights. ResultsThe analytic sample included 15,591 adults from the 2022-2025 SOHEA surveys with complete data (52.5% of the total N=29,679); 12% identified as LGBTQ+. Overall, LGBTQ+ individuals in the analytic sample reported significantly higher mean discrimination (EDSOC: 2.97, SD=4.99) and microaggression (DOCS: 2.19, SD=3.22) scores than non-LGBTQ+ individuals (EDSOC: 1.72, SD=3.79; DOCS: 1.62, SD=2.80; p<0.001). Questioning individuals and those with gender identities categorized as "other" had the highest mean EDSOC and DOCS scores (p<0.001). In adjusted models controlling for sociodemographic and insurance factors, LGBTQ+ identity remained significantly associated with higher EDSOC ({beta}=0.16, 95% CI=0.11-0.21) and DOCS ({beta}=0.08, 95% CI=0.03-0.13) scores. Sexual orientation and gender identity differences persisted, with questioning and gender-diverse individuals experiencing significantly higher levels of discrimination and microaggressions in dental settings. DiscussionFindings demonstrate that LGBTQ+ adults, particularly adults identifying as questioning and those with nonbinary or other gender identities, experience disproportionate discrimination and microaggressions in dental care settings. Addressing interpersonal and structural sources of bias in oral health care is critical to advancing equity and improving access to respectful, high-quality care for LGBTQ+ populations.

To attract mating partners, female mammals communicate their reproductive status through one or multiple sensory modalities, providing redundant or complementary information. Chimpanzees (Pan troglodytes) are an excellent model for studying multimodal communication. Exaggerated sexual swellings of females serve as a visual proxy for ovulation but increased male mating interest during maximum swelling suggests that olfactory cues may pinpoint fertility more accurately than the swelling alone. Here, we combined gas chromatography-mass spectrometry, hormonal analyses, and bioassays to examine (1) whether chemical composition of female anogenital odours changes during the fertile period, and (2) whether males are able to detect these changes. Our results suggest that, in addition to prominent olfactory changes associated with swelling stages, chemical cues provide complementary information regarding the timing of the fertile window. These changes, however, are minor compared to those related to swelling stages. Male behavioural responsiveness in bioassays was too low to draw conclusions regarding their ability to detect these subtle shifts when presented with a chemical cue only. Overall, our findings support the existence of a multimodal fertility cue in chimpanzees, wherein visual signals are complemented by subtle olfactory changes indicating the timing of the fertile period.

Background: Sexual and gender minorities (SGM), including men who have sex with men (MSM) and transgender women, often face stigma, legal constraints, and limited access to sexual and reproductive health services. These conditions restrict prevention and care, increasing vulnerability to HIV and human papillomavirus (HPV) infections. While strong HIV-HPV interaction is documented in high-income settings, evidence from low- and middle-income countries remains limited. This study examines the burden, co-infection dynamics, and progression of HPV infection and anal dysplasia among MSM and transgender women in Pakistan. Methods: A cross-sectional study was conducted between September 2015 and October 2016 among men who have sex with men (MSM) and transgender women recruited from sexual health and antiretroviral therapy centers in Karachi. Eligible participants were aged [&ge;]18 years and self-reported anal sex within the past 6 months (N=298). Two anal specimens were collected for HPV DNA detection and genotyping using PCR, and anal squamous intraepithelial lesions (ASIL) were assessed cytologically using the Bethesda classification. Associations were estimated using Cox proportional hazards regression algorithms to derive prevalence ratios (PRs). Results: Among participants, 44% (n=133) were living with HIV. Overall HPV prevalence was 65.1%, rising to 87% among HIV-positive individuals compared to 48% among those without HIV ({chi}{superscript 2}p[&le;]0.001). Likewise 28.9% of participants living with HIV were infected with two or more than two types of HPV as compared with 18.8% participants without HIV ({chi}{superscript 2}p[&le;]0.001). HIV infection was strongly associated with HPV acquisition (adjusted PR 2.81, 95% CI 2.16-3.82). Among HPV-positive participants (n=194), 58.8% were co-infected with HIV. High-risk HPV was highly prevalent among those living with HIV (83.2% vs. 35.3% ({chi}{superscript 2}p[&le;]0.001)), with HPV16 as the dominant oncogenic type. Multiple HPV infections were more common among HIV-positive individuals ({chi}{superscript 2}p[&le;]0.001), and HIV seropositivity was 3.43 (95% CI: 2.55-3.51) times higher among those with high-risk HPV. Co-infected participants demonstrated prolonged smoking, longer duration of sex work, high-intensity sex work with limited condom negotiation, and higher prevalence of anal warts (all p<0.05). Anal dysplasia (ASIL) was present in 35% of participants and was higher among HIV-positive individuals (42.4% vs. 28.1%, p<0.001). HIV-HPV co-infection was independently associated with ASIL (adjusted PR 1.75, 95% CI 1.07-2.88), while high-risk HPV further amplified this risk (PR 3.04, 95% CI 1.75-5.26). Conclusion: These findings demonstrate a biological continuum in HIV-positive MSM and transgender women, where HIV increases HPV acquisition, persistence, and multiplicity, accelerating progression to anal dysplasia. This reflects a syndemic shaped by biological interaction and structural vulnerability. Integrating HPV screening and vaccination within HIV services is essential to interrupt progression to cancer in this high-risk population.

Background and AimsSteatotic liver disease (SLD) is characterized by excessive lipid accumulation in hepatocytes, and alcohol consumption may modify the disease course, but the evidence is inclusive. This systematic review and meta-analysis aimed to holistically evaluate the impact of mild, moderate, and high levels of alcohol consumption on hepatic and extrahepatic outcomes in SLD. MethodsWe systematically searched EMBASE, MEDLINE, Web of Science, and the Cochrane Central Register of Controlled Trials for relevant studies. The study outcomes included liver related events, malignancy, mortality and cardiovascular disease among adults with SLD who consumed alcohol. ResultsOf 2228 records identified, twenty-six studies comprising 466611 adults with SLD were included. High alcohol consumption was associated with an increased risk of liver-related events compared with abstinence (2.97, 95% CI 1.61-5.50; p<0.001), and a similar association was observed among alcohol drinkers overall (HR 1.93, 95% CI 1.60-2.33; p<0.001). Moderate alcohol consumption was associated with a higher incidence of malignancy (HR 1.41, 95% CI 1.13-1.78; p=0.677). In contrast, mild alcohol consumption was associated with lower all-cause mortality compared with abstinence (HR 0.88, 95% CI 0.78-0.98; p=0.001). No association was observed between alcohol consumption and cardiovascular disease incidence or hepatocellular carcinoma ConclusionsAlcohol intake may increase the risk of liver-related complications and cancer risk in individuals with SLD. Mild alcohol consumption was associated with lower all-cause mortality, and alcohol intake showed no association with cardiovascular disease incidence. Further studies are needed to clarify the dose-dependent effects of alcohol on hepatic and extrahepatic outcomes in SLD.