5. Stages in sexual development Genetic Gonadal sex Phenotypic sex Neuronal sex Gender identity
6. Cytogenetic techniques Q-bands: identification of Y & 21, 22 Quinacrinehcl UV G-bands: identification of all chromosomes Giemsa Based on bands in homologous chromosomes C-bands: reflect constitutive heterochromatin Repetitive DNA without specified message Alkaline denaturation Interstitial location in Y Determine the origin of fault
51. Mechanisms in brain differentiation Altering neuronal genomic expression Regional cell growth Proliferation Death, cell number, size, or packing density Early migrational patterns Dendritic growth Neuronal myelination
52. Brain types Sexually dimorphic nucleus of medial preoptic area (SDN-POA) male>2.5female Preoptic-anterior hypothalamic area Men: higher proportion of gray matter to cranial volume Women: higher proportion of white matter Women: larger corpus callosum No sex differences in general IQ Men typically excel in spacial & quantitative abilities Women: on tasks involving verbal abilities, perceptual speed and accuracy, and fine motor skills Men: more specialized skill
53. Alpha-feto-protein Is a globulin Produced by Fetal liver Yalk sac Starts at 4th week Max secretion at 24th week Absent at 24th week Regulate steroid hormones
58. Progesterone & neurosteroids Schwann cells secrete progesterone, important in myelination Progesterone stimulate myelin protein synthesis Convert to 5α-OH prog. by 5α-reductase Then to 3α,5β-OH-prog. by 3α-OHS-oxidoreductase in glial cells, Act on GABA & NMDA receptor(potentiate)
59.
60. Aromatase & breast cancer 1 Schematic of metabolic pathways in an ER-positive cell that can be affected by AIs. The left side represents the active pathways and cellular responses under normal estrogen control. The right side depicts the blockade of pathways involving ERs and the resultant cellular responses. AI, aromatase inhibitor; E2, estradiol; ER, estrogen receptor; MAP, mitogen-activated protein; PI-3, phosphoinositide-3; RTK, receptor tyrosine kinase; SERD, selective estrogen receptor down-regulator; SERM, selective estrogen receptor modulator
64. Gonadotropin secretion Testis activity: at 7th week Ovary activity: at 14th week Portal system is intact at 11.5th week Axon fibers of LRH in ME at 16th week Functional fetal LRH at the end of first trimester
71. Control of HT on gonadotropin secretion Maturation of sex steroid receptors in LRH neurons Maturation of sex hormone-independent inhibitory pathways
72. Cyclic secretion of gonadotropins In men: LH: every 90-120min 1μg/min for 6min every hr Mid and late luteal phase: every 3-4 hrs
76. Puberty gene GPR54 defect In Saudi family Hypogonadotrophichypogonadism Puberty delay Sexual infantilism Low GnRH but responsible pituitary to exogenous GnRH
77. Puberty gene GPR54 On chromosome 19 Encodes a Gprotein–coupled receptor A member of rhodopsin family of G-pr coupled receptor This receptoris essential for normal GnRH physiologyand for puberty. Metastin(kisspeptin-1) is an agonist on the same receptor Secreted by placenta Normal delivery Defect in X-linked kallmann’s syndrome
102. Pineal gland Pinealocytes: produce and secret melatonin Peptidergic neuron-like cells Interstitial cells Perivascular phagocytes Pineal neurons Pineal calcification is hi in regions with hi frequency of breast cancer
103. melatonin Melatonin was discovered in 1958 By American physician Aaron B. Lerner Derivative of tryptophan
106. Light signal transmition Retina SCN of HT PVN Intermediolateral cell column Superior cervical ganglia Pineal gland
107.
108. Melatonin receptores Most abundant in SCN & anterior pituitary( pars tuberalis) Mel1A & Mel1B Block out the blue rays of light to avoid postpartum depression