NEUR30003 Lecture Notes - Lecture 6: Y Chromosome, Gout, Dihydrotestosterone
Lecture 2. 3: sex, steroids, and the nervous system. Chromosomal sex: genetic sex individual"s sex chromosomes: not, gender identity, sexual orientation. Sex chromosomes at the location of genes responsible for gonad development -> determine the primary source and type of sex hormones. Sry gene determined whether it will be a testes or ovary: no y chromosome -> female. Steroid hormones are lipid-soluble so pass through membranes into all cells: neurotransmitters are normally water-soluble (don"t cross membranes, difficult to localise where the steroid is working depends on receptors. Common precursor cholesterol (all steroids come from this) Aromatase expression is critical for determining whether androgen or estrogen is the active factor: cells with aromatase can convert testosterone to estradiol. Blue = androgen bind to androgen receptor: testosterone its derivative = dihydrotestosterone. Pink = estrogen: estradiol dominant estrogen. Males: early (pre-birth; 2nd trimester) transient synthesis of testosterone causes masculinisation of genitalia, levels increase at puberty to (relatively) constant adult levels.