Mouse MRI shows brain areas larger in males emerge earlier than those larger in females

2017 ◽  
Author(s):  
Lily R. Qiu ◽  
Darren J. Fernandes ◽  
Kamila U. Szulc ◽  
Jun Dazai ◽  
Brian J. Nieman ◽  
...  
Keyword(s):  
Sex Differences ◽  
Time Course ◽  
Developmental Trajectories ◽  
Neuropsychiatric Disorders ◽  
Developmental Differences ◽  
Sexually Dimorphic ◽  
Whole Brain ◽  
Male And Female ◽  
Expression Of Genes ◽  
Manganese Enhanced Mri

Sex differences exist in behaviours, disease and neuropsychiatric disorders. Sexual dimorphisms however, have yet to be studied across the whole brain and across a comprehensive time course of postnatal development. We used manganese-enhanced MRI (MEMRI) to longitudinally image male and female C57BL/6J mice across 9 time points, beginning at postnatal day 3. We recapitulated findings on canonically dimorphic areas, demonstrating the ability of MEMRI to study neuroanatomical sex differences. We discovered, upon whole-brain volume correction, that neuroanatomical regions larger in males develop early in life, while regions larger in females develop in peripubertal life. Furthermore, we found groups of areas with shared sexually dimorphic developmental trajectories that reflect behavioural and functional networks, and expression of genes involved with sex processes. Our results demonstrate the ability of MEMRI to reveal comprehensive developmental differences between male and female brains, which will improve our understanding of sex-specific predispositions to various neuropsychiatric disorders.

Evolution, Societal Sexism, and Universal Average Sex Differences in Cognition and Behavior

2018 ◽  
Author(s):  
Lee Ellis
Keyword(s):  
Sex Differences ◽  
Cross Cultural ◽  
Past Century ◽  
Sexually Dimorphic ◽  
Social Scientists ◽  
Industrial Countries ◽  
Expression Of Genes ◽  
And Behavior ◽  
Industrial Societies ◽  
Shed Light

During the past century, social scientists have documented many cross-cultural sex differences in personality and behavior, quite a few of which now appear to be found in all human societies. However, contrary to most scientists’ expectations, these so-called universal sex differences have been shown to be more pronounced in Western industrial societies than in most non-Western developing societies. This chapter briefly reviews the evidence bearing on these findings and offers a biologically based theory that could help shed light on why cross-cultural sex differences exist. The following hypothesis is offered: The expression of many genes influencing sexually dimorphic traits is more likely among descendants of couples who are least closely related to one another. If so, societies in which out-marriage is normative (i.e., Western industrial countries) will exhibit a stronger expression of genes for sexually dimorphic traits compared to societies in which consanguineal marriages are common.

scholarly journals Transcriptome analysis of the human tibial nerve identifies sexually dimorphic expression of genes involved in pain, inflammation and neuro-immunity

2018 ◽  
Author(s):  
Pradipta Ray ◽  
Jawad Khan ◽  
Andi Wangzhou ◽  
Diana Tavares-Ferreira ◽  
Armen N. Akopian ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Pain ◽  
Sex Differences ◽  
Molecular Mechanisms ◽  
Tibial Nerve ◽  
Sexually Dimorphic ◽  
Pain Mechanisms ◽  
Expression Of Genes ◽  
Sexually Dimorphic Expression ◽  
Insight Into

AbstractSex differences in gene expression are important contributors to normal physiology and mechanisms of disease. This is increasingly apparent in understanding and potentially treating chronic pain where molecular mechanisms driving sex differences in neuronal plasticity are giving new insight into why certain chronic pain disorders preferentially affect women versus men. Large transcriptomic resources are increasingly available and can be used to mine for sex differences and molecular insight using donor cohorts. We analyzed more than 250 human tibial nerve (hTN) transcriptomes from the GTex Consortium project to gain insight into sex-dependent gene expression in the peripheral nervous system (PNS). We discover 149 genes with sex differential expression. Many of the genes upregulated in men are associated with inflammation, and appear to be primarily expressed by glia or immune cells. In women, we find the differentially upregulated transcription factor SP4 that drives a regulatory program, and may impact sex differences in PNS physiology. Many of these 149 DE genes have some previous association with chronic pain but few of them have been explored thoroughly. Additionally, using clinical data in the GTex database, we identify a subset of differentially expressed (DE) genes in diseases associated with chronic pain, arthritis and type II diabetes. Our work identifies sexually dimorphic gene expression in the human PNS with implications for discovery of sex-specific pain mechanisms.

scholarly journals Divergent sex differences in functional brain connectivity networks in excessively drinking C57BL/6J mice

2021 ◽  
Author(s):  
Solal Bloch ◽  
Jennifer A. Rinker ◽  
Alex CW Smith ◽  
Priyattam J Shiromani ◽  
Damian Wheeler ◽  
...  
Keyword(s):  
Sex Differences ◽  
Functional Connectivity ◽  
Alcohol Drinking ◽  
Network Connectivity ◽  
Functional Network ◽  
Whole Brain ◽  
Male And Female ◽  
Female Mice ◽  
Functional Network Connectivity ◽  
Water Drinking

Individuals with alcohol use disorder continue to drink in excess despite the health and societal consequences, and the rate of problematic drinking and alcohol-related harms is increased in women. Clinical imaging studies report widespread adaptations in brain structure after chronic, heavy drinking, and alcohol-related cues enhance brain reactivity in reward-related regions. In rodents, alcohol drinking induces expression of the immediate early gene c-Fos, which can be a marker of cellular activity, across multiple brain regions. Recent evidence also suggests that abstinence from chronic intermittent alcohol exposure can produce mesoscale changes in c-Fos expression. However, there is a substantial gap in our understanding of how excessive drinking affects functional connectivity networks to influence alcohol-seeking behaviors. For this study, male and female C57BL/6J mice were given access to either water or a choice between water and ethanol in the intermittent access drinking model for 4 weeks. After a short-access drinking session, whole brains from high alcohol drinking male and female mice and water drinking controls were then subjected to c-Fos immunolabeling, iDISCO+ clearing, light sheet imaging, and whole-brain c-Fos mapping. Correlation matrices were then generated and graph theoretical statistical approaches were used to determine changes in functional connectivity across sex and drinking condition. We observed robust sex differences in the network of c-Fos+ cells in water drinking mice, and excessive alcohol drinking produce divergent and robust changes in functional network connectivity in male and female mice. In addition, these analyses identified novel hub regions in excessively drinking mice that were unique for each sex. In conclusion, the whole-brain c-Fos mapping analysis identified sex difference in functional network connectivity and unique and understudied regions that may play a critical role in controlling excessive ethanol drinking in male and female mice.

Temperature affects the ontogeny of sexually dimorphic cuticular hydrocarbons in Drosophila melanogaster

2002 ◽  
Vol 205 (20) ◽  
pp. 3241-3249 ◽  
Author(s):  
Fabrice Savarit ◽  
Jean-François Ferveur
Keyword(s):  
Drosophila Melanogaster ◽  
Cuticular Hydrocarbons ◽  
Time Course ◽  
Mate Recognition ◽  
Effect Of Temperature ◽  
Sexually Dimorphic ◽  
Shock Pulse ◽  
Male And Female ◽  
Different Temperatures ◽  
Transgenic Strains

SUMMARY Hydrocarbons on the cuticle of mature Drosophila melanogasterflies play a crucial role in mate recognition, and protect against dehydration. We measured the effect of temperature on mature cuticular hydrocarbons (CHs) by (i) rearing two control strains at different temperatures, (ii) shifting the temperature after metamorphosis and (iii)inducing a single heat-shock pulse in control and heat-sensitive transgenic strains, over a period of 3 days following adult eclosion. This study describes the time course of the events involved in the production of male-and female-predominant CHs. We also found that `immature' CHs, sexually monomorphic CHs on younger flies, were not affected by these treatments.

scholarly journals Sex differences in electrophysiological properties of mouse mPOA neurons revealed by in vitro whole-cell recordings

2019 ◽  
Author(s):  
Wen Zhang ◽  
Shuai-shuai Li ◽  
Zhuo-lei Jiao ◽  
Ying Han ◽  
Zi-yue Wang ◽  
...  
Keyword(s):  
Sex Differences ◽  
Patch Clamp ◽  
Gonadal Hormones ◽  
Male Mating ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Whole Cell ◽  
Electrophysiological Properties ◽  
Whole Cell Patch Clamp

AbstractThe medial preoptic area (mPOA) of the hypothalamus is sexually dimorphic and controls sexually dimorphic display of male mating and parental care. Yet, despite extensive characterization of sex differences in the mPOA, we know surprisingly little about whether or how male and female mPOA neurons differ electrophysiologically, which relate more directly to neuronal firing and behavioral pattern generation. In this study, we performed whole-cell patch clamp recordings of the mPOA in acute brain slices cut from virgin adult mice, and compared in total 29 electrophysiological parameters between male and female mPOA neurons. We find that resting membrane potential (Vm), input resistance (Rm), time constant (τm), threshold (Vth) and minimum current (rheobase) required to generate an action potential differ significantly between male and female in a cell-type dependent manner. Nonetheless, there is little evidence for profuse sex differences in neuronal excitability, except for a higher probability of rebound neurons in males. Depletion of male gonadal hormones in adulthood partially de-masculinizes sexually dimorphic electrophysiological parameters, suggesting that some of these sex differences may establish during development. Furthermore, as a demonstration of the behavioral relevance of these sex differences, we show that pharmacologic blockage of currents mediated by T-type Ca2+ channel, which underlie rebound and tends to be larger in male mPOA neurons, result in behavioral deficits in male mating. In summary, we have identified key sex differences in electrophysiological properties of mPOA neurons that likely contribute to sexually dimorphic display of behaviors.Significance StatementSex represents an important biological variable that impact an individual’s behaviors, physiology and disease susceptibility. Indeed, sex differences in the nervous system manifest across many different levels and scales. Yet, throughout previous multifaceted investigations on sex differences in the brain, electrophysiological characterizations, which could potentially bridge cellular and molecular sex differences with sexually dimorphic brain functions and behaviors, remains scant. Here, focusing on an evolutionarily conserved sexually dimorphic nucleus, we investigated sex differences in electrophysiological properties of mPOA neurons and its modulation by gonadal hormones in adult males via in vitro whole-cell patch clamp. As a result, we identified novel sex differences in electrophysiological properties that likely contribute to sexually dimorphic display of behaviors and physiological functions.

scholarly journals Sex differences in electrophysiology: P200 event-related potential evidence

2018 ◽  
Vol 9 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Ali K. Bourisly ◽  
Ali Shuaib
Keyword(s):  
Sex Differences ◽  
Brain Function ◽  
Sensor Array ◽  
Latency Period ◽  
Neuropsychiatric Disorders ◽  
Event Related Potential ◽  
Peak Amplitude ◽  
Sexually Dimorphic ◽  
Oddball Task

Abstract We conducted an event-related potential (ERP) study using a 256-channel dense sensor array electroencephalography (EEG) system to examine how, and if the P200 neurophysiological signal is sexually dimorphic. We had two groups of participants: females (n= 15, mean age = 40.6 years old) and males (n = 15, mean age = 39.0 years old). ERPs from all participants were recorded while the participants performed an oddball task. Results showed that males on average had a significantly larger P200 peak amplitude and a significantly shorter P200 latency period. These results indicate that the P200 ERP is affected by sex. Therefore, suggesting that sex differences exist on an electrophysiological level, which may aid in better understanding of sex-biased biological influences, behaviors, neuropsychiatric disorders, and general brain function.

scholarly journals Investigating the reliability and sex differences of digit lengths, ratios, and hand measures in infants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luisa Ernsten ◽  
Lisa M. Körner ◽  
Martin Heil ◽  
Gareth Richards ◽  
Nora K. Schaal
Keyword(s):  
Sex Differences ◽  
Measurement Techniques ◽  
Directional Asymmetry ◽  
Computer Assisted ◽  
Sexually Dimorphic ◽  
Digit Ratios ◽  
Androgen Exposure ◽  
Prenatal Androgen Exposure ◽  
Test Retest Reliability ◽  
Prenatal Androgen

AbstractHands and digits tend to be sexually dimorphic and may reflect prenatal androgen exposure. In the past years, the literature introduced several hand and digit measures, but there is a lack of studies in prepubertal cohorts. The available literature reports more heterogeneous findings in prepubertal compared to postpubertal cohorts. The comparability of the available studies is further limited by the study design and different measurement techniques. The present study compared the reliability and sex differences of available hand and digit measures, namely digit lengths of 2D, 3D, 4D, 5D, digit ratios 2D:4D, 2D:5D, 3D:4D, 3D:5D, 4D:5D, relative digit lengths rel2, rel3, rel4, rel5, directional asymmetry of right and left 2D:4D (Dr-l), hand width, length, and index of 399 male and 364 female 6-month-old German infants within one study using only indirect and computer-assisted measurements. The inter-examiner reliability was excellent while the test-retest reliability of hand scans was only moderate to high. Boys exhibited longer digits as well as wider and longer hands than girls, but smaller digit ratios, with ratios comprising the fifth digit revealing the largest effect sizes. Other hand and digit ratios revealed sex differences to some extent. The findings promote the assumption of sexual dimorphic hand and digit measures. However, by comparing the results of the available literature, there remains an uncertainty regarding the underlying hypothesis. Specifically in prepubertal cohorts, i.e. before the influence of fluctuating hormones, significant effects should be expected. It seems like other factors than the influence of prenatal androgens contribute to the sexual dimorphism in hand and digit lengths.

scholarly journals Stem cell treatment improves post stroke neurological outcomes: a comparative study in male and female rats

2021 ◽  
pp. svn-2020-000834
Author(s):  
Koteswara Rao Nalamolu ◽  
Bharath Chelluboina ◽  
Casimir A Fornal ◽  
Siva Reddy Challa ◽  
David M Pinson ◽  
...  
Keyword(s):  
Stem Cells ◽  
Sex Differences ◽  
Motor Function ◽  
Infarct Volume ◽  
Female Rats ◽  
Human Umbilical Cord ◽  
Male And Female ◽  
Post Stroke ◽  
Male And Female Rats ◽  
Males And Females

Background and purposeThe therapeutic potential of different stem cells for ischaemic stroke treatment is intriguing and somewhat controversial. Recent results from our laboratory have demonstrated the potential benefits of human umbilical cord blood-derived mesenchymal stem cells (MSC) in a rodent stroke model. We hypothesised that MSC treatment would effectively promote the recovery of sensory and motor function in both males and females, despite any apparent sex differences in post stroke brain injury.MethodsTransient focal cerebral ischaemia was induced in adult Sprague-Dawley rats by occlusion of the middle cerebral artery. Following the procedure, male and female rats of the untreated group were euthanised 1 day after reperfusion and their brains were used to estimate the resulting infarct volume and tissue swelling. Additional groups of stroke-induced male and female rats were treated with MSC or vehicle and were subsequently subjected to a battery of standard neurological/neurobehavioral tests (Modified Neurological Severity Score assessment, adhesive tape removal, beam walk and rotarod). The tests were administered at regular intervals (at days 1, 3, 5, 7 and 14) after reperfusion to determine the time course of neurological and functional recovery after stroke.ResultsThe infarct volume and extent of swelling of the ischaemic brain were similar in males and females. Despite similar pathological stroke lesions, the clinical manifestations of stroke were more pronounced in males than females, as indicated by the neurological scores and other tests. MSC treatment significantly improved the recovery of sensory and motor function in both sexes, and it demonstrated efficacy in both moderate stroke (females) and severe stroke (males).ConclusionsDespite sex differences in the severity of post stroke outcomes, MSC treatment promoted the recovery of sensory and motor function in male and female rats, suggesting that it may be a promising treatment for stroke.

Role of sex hormones in lung cancer

2021 ◽  
pp. 153537022110196
Author(s):  
Nathalie Fuentes ◽  
Miguel Silva Rodriguez ◽  
Patricia Silveyra
Keyword(s):  
Lung Cancer ◽  
Sex Differences ◽  
Sex Hormones ◽  
Hormone Receptors ◽  
Occupational Exposures ◽  
Lung Carcinogenesis ◽  
Male And Female ◽  
Female Sex ◽  
Incidence And Mortality ◽  
Cancer Rates

Lung cancer represents the world’s leading cause of cancer deaths. Sex differences in the incidence and mortality rates for various types of lung cancers have been identified, but the biological and endocrine mechanisms implicated in these disparities have not yet been determined. While some cancers such as lung adenocarcinoma are more commonly found among women than men, others like squamous cell carcinoma display the opposite pattern or show no sex differences. Associations of tobacco product use rates, susceptibility to carcinogens, occupational exposures, and indoor and outdoor air pollution have also been linked to differential rates of lung cancer occurrence and mortality between sexes. While roles for sex hormones in other types of cancers affecting women or men have been identified and described, little is known about the influence of sex hormones in lung cancer. One potential mechanism identified to date is the synergism between estrogen and some tobacco compounds, and oncogene mutations, in inducing the expression of metabolic enzymes, leading to enhanced formation of reactive oxygen species and DNA adducts, and subsequent lung carcinogenesis. In this review, we present the literature available regarding sex differences in cancer rates, associations of male and female sex hormones with lung cancer, the influence of exogenous hormone therapy in women, and potential mechanisms mediated by male and female sex hormone receptors in lung carcinogenesis. The influence of biological sex on lung disease has recently been established, thus new research incorporating this variable will shed light on the mechanisms behind the observed disparities in lung cancer rates, and potentially lead to the development of new therapeutics to treat this devastating disease.

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