Marc Breedlove
Marc Breedlove is a professor of neuroscience at Michigan State University. His research focuses on how hormones, particularly prenatal and perinatal sex steroids, shape brain development, gendered behavior, and sexual orientation. His published work examines neural sex differences, the evolutionary and physiological mechanisms of sexual behavior, and anatomical correlates such as 2D:4D finger-length ratios.
Fact-checked episodes
Publications
- Express yourself.
- Finger pointing: Why bias against 2D:4D ratios doesn't add up.
- Sexual orientation is associated with 2D:4D finger length ratios in both sexes: an updated and expanded meta-analysis.
- Lumping Sexes and Splitting Genders.
- Loss of TRPC2 function in mice alters sex differences in brain regions regulating social behaviors.
- Evidence for Perinatal Steroid Influence on Human Sexual Orientation and Gendered Behavior.
- Low Perinatal Androgens Predict Recalled Childhood Gender Nonconformity in Men.
- The De-Scent of Sexuality: Did Loss of a Pheromone Signaling Protein Permit the Evolution of Same-Sex Sexual Behavior in Primates?
- Relationships between ovarian hormone concentrations and mental rotations performance in naturally-cycling women.
- Testosterone works through androgen receptors to modulate neuronal response to anxiogenic stimuli.
- Differences in digit ratios between gay men who prefer receptive versus insertive sex roles indicate a role for prenatal androgen.
- Response to Commentaries: Sniffing Out Consensus on the Evolution of Primate Same-Sex Sexual Behavior.
- Evidence that perinatal ovarian hormones promote women's sexual attraction to men.
- Heterozygosity of the major histocompatibility complex predicts later self-reported pubertal maturation in men.
- No evidence that hormonal contraceptive use or circulating sex steroids predict complex emotion recognition.
- Through a glass, darkly: Human digit ratios reflect prenatal androgens, imperfectly.
- Timing of peripubertal steroid exposure predicts visuospatial cognition in men: Evidence from three samples.
- Muscle BDNF improves synaptic and contractile muscle strength in Kennedy's disease mice in a muscle-type specific manner.
- Pubertal timing predicts adult psychosexuality: Evidence from typically developing adults and adults with isolated GnRH deficiency.
- Disease Affects Bdnf Expression in Synaptic and Extrasynaptic Regions of Skeletal Muscle of Three SBMA Mouse Models.
- Oestrogen and androgen receptor activation contribute to the masculinisation of oxytocin receptors in the bed nucleus of the stria terminalis of rats.
- Replicable data for digit ratio differences.
- O Gay New World: Ramifications of the Maternal Immune Hypothesis.
- Pre-clinical symptoms of SBMA may not be androgen-dependent: implications from two SBMA mouse models.
- Sex differences in the traumatic stress response: PTSD symptoms in women recapitulated in female rats.
- Sex differences in the traumatic stress response: the role of adult gonadal hormones.
- Consequences of cesarean delivery for neural development.
- Neurochemicals Drawing the Line Between Love and Hate.
- Prenatal Influences on Human Sexual Orientation: Expectations versus Data.
- Response to Commentaries.
- Down, But Not Out: Partial Elimination of Androgen Receptors in the Male Mouse Brain Does Not Affect Androgenic Regulation of Anxiety or HPA Activity.
- Sex and laterality differences in medial amygdala neurons and astrocytes of adult mice.
- Sexual Orientation, Controversy, and Science.
- Defects in Neuromuscular Transmission May Underlie Motor Dysfunction in Spinal and Bulbar Muscular Atrophy.
- Neuromuscular junctions are pathological but not denervated in two mouse models of spinal bulbar muscular atrophy.
- Non-Cell-Autonomous Regulation of Retrograde Motoneuronal Axonal Transport in an SBMA Mouse Model.
- Age differences in prenatal testosterone's protective effects on disordered eating symptoms: developmental windows of expression?
- Fulfilling desire: evidence for negative feedback between men's testosterone, sociosexual psychology, and sexual partner number.
- Contractile dysfunction in muscle may underlie androgen-dependent motor dysfunction in spinal bulbar muscular atrophy.
- Androgen-dependent loss of muscle BDNF mRNA in two mouse models of SBMA.
- New knockout model confirms a role for androgen receptors in regulating anxiety-like behaviors and HPA response in mice.
- Antiandrogen flutamide protects male mice from androgen-dependent toxicity in three models of spinal bulbar muscular atrophy.
- Androgen receptors mediate masculinization of astrocytes in the rat posterodorsal medial amygdala during puberty.
- Androgen receptors in muscle fibers induce rapid loss of force but not mass: implications for spinal bulbar muscular atrophy.
- The emergence of sex differences in risk for disordered eating attitudes during puberty: a role for prenatal testosterone exposure.
- Ontogeny of androgen receptor expression in spinal nucleus of the bulbocavernosus motoneurons and their target muscles in male mice.
- Astrocytes in the rat medial amygdala are responsive to adult androgens.
- Prenatal flutamide enhances survival in a myogenic mouse model of spinal bulbar muscular atrophy.
- The organizational role of testicular hormones and the androgen receptor in anxiety-related behaviors and sensorimotor gating in rats.
- Male rats with the testicular feminization mutation of the androgen receptor display elevated anxiety-related behavior and corticosterone response to mild stress.
- Impaired motoneuronal retrograde transport in two models of SBMA implicates two sites of androgen action.
- Salivary testosterone does not predict mental rotation performance in men or women.
- The testosterone two-step is really a minuet.
- Astrocytes in the amygdala.
- Neonatal androgen-dependent sex differences in lumbar spinal cord dopamine concentrations and the number of A11 diencephalospinal dopamine neurons.
- Human trust: testosterone raises suspicion.
- Minireview: Organizational hypothesis: instances of the fingerpost.
- Differential expression and regulation of brain-derived neurotrophic factor (BDNF) mRNA isoforms in androgen-sensitive motoneurons of the rat lumbar spinal cord.
- Stress affects a gastrin-releasing peptide system in the spinal cord that mediates sexual function: implications for psychogenic erectile dysfunction.
- Recovery of function in a myogenic mouse model of spinal bulbar muscular atrophy.
- Potential hormonal mechanisms of attention-deficit/hyperactivity disorder and major depressive disorder: a new perspective.
- Androgen regulates the sexually dimorphic gastrin-releasing peptide system in the lumbar spinal cord that mediates male sexual function.
- Time course of adult castration-induced changes in soma size of motoneurons in the rat spinal nucleus of the bulbocavernosus.
- Effects of sex hormones on associative learning in spontaneously hypertensive rats.
- Sexual dimorphism and steroid responsiveness of the posterodorsal medial amygdala in adult mice.
- Genetic and environmental influences on 2D:4D finger length ratios: a study of monozygotic and dizygotic male and female twins.
- Spatial ability and prenatal androgens: meta-analyses of congenital adrenal hyperplasia and digit ratio (2D:4D) studies.
- Sexual dimorphism in neuronal number of the posterodorsal medial amygdala is independent of circulating androgens and regional volume in adult rats.
- Hand asymmetry in heterosexual and homosexual men and women: relationship to 2D:4D digit ratios and other sexually dimorphic anatomical traits.
- Prenatal hormone exposure and risk for eating disorders: a comparison of opposite-sex and same-sex twins.
- Gonadal steroids regulate neural plasticity in the sexually dimorphic nucleus of the preoptic area of adult male and female rats.
- The role of androgen receptors in the masculinization of brain and behavior: what we've learned from the testicular feminization mutation.
- Masculinized finger-length ratios of boys, but not girls, are associated with attention-deficit/hyperactivity disorder.
- Sexually dimorphic gastrin releasing peptide system in the spinal cord controls male reproductive functions.
- Mice with the testicular feminization mutation demonstrate a role for androgen receptors in the regulation of anxiety-related behaviors and the hypothalamic-pituitary-adrenal axis.
- Sex differences and laterality in astrocyte number and complexity in the adult rat medial amygdala.
- Androgen receptors are required for full masculinization of the ventromedial hypothalamus (VMH) in rats.
- Androgen-sensitivity of somata and dendrites of spinal nucleus of the bulbocavernosus (SNB) motoneurons in male C57BL6J mice.
- Androgen-dependent regulation of brain-derived neurotrophic factor and tyrosine kinase B in the sexually dimorphic spinal nucleus of the bulbocavernosus.
- Effects of the testicular feminization mutation (tfm) of the androgen receptor gene on BSTMPM volume and morphology in rats.
- Pubertal growth of the medial amygdala delayed by short photoperiods in the Siberian hamster, Phodopus sungorus.
- Homosexual mating preferences from an evolutionary perspective: sexual selection theory revisited.
- Behavioural neurobiology: females can also be from Mars.
- Overexpression of wild-type androgen receptor in muscle recapitulates polyglutamine disease.
- Interaction of fraternal birth order and handedness in the development of male homosexuality.
- Preliminary evidence that gonadal hormones organize and activate disordered eating.
- Defending the brain from estrogen.
- Sex differences in digit ratio (2D:4D) are disrupted in adolescents with schizotypal personality disorder: altered prenatal gonadal hormone levels as a risk factor.
- O brother, where art thou? The fraternal birth-order effect on male sexual orientation.
- Anabolic responsiveness of skeletal muscles correlates with androgen receptor protein but not mRNA.
- Tackling investigator noncompliance: Cooperation counts.
- Partial demasculinization of several brain regions in adult male (XY) rats with a dysfunctional androgen receptor gene.
- A reanalysis of five studies on sexual orientation and the relative length of the 2nd and 4th fingers (the 2D:4D ratio).
- Brain aromatase: dyed-in-the-wool homosexuality.
- Brain gender: prostaglandins have their say.
- Sexual differentiation of the vertebrate nervous system.
- Steroid hormone masculinization of neural structure in rats: a tale of two nuclei.
- Got milk? Oxytocin triggers hippocampal plasticity.
- Both estrogen receptors and androgen receptors contribute to testosterone-induced changes in the morphology of the medial amygdala and sexual arousal in male rats.
- Differences in finger length ratios between self-identified "butch" and "femme" lesbians.
- Photoperiod-dependent response to androgen in the medial amygdala of the Siberian hamster, Phodopus sungorus.
- Sexual dimorphism in digit-length ratios of laboratory mice.
- Evidence that androgen acts through NMDA receptors to affect motoneurons in the rat spinal nucleus of the bulbocavernosus.
- Masculinized finger length patterns in human males and females with congenital adrenal hyperplasia.