Development of Behavior Flashcards
dimorphism
Difference in male and female
Example: hormonal effect, brain size, something one sex perform that the other cant
2 ways it works: either creates behavioral difference or creates similarities
1959 Pioneering study by Phoenix, Goy, Gerall, and Young
studied Guinea pigs, Guinea pigs have 69 day gestation rate, females have lower anogenital distance than males
Injected moms w/ testosterone proportionate (androgen) 1x per day between 10-68 days
Mother offspring with high dose: males normal, female masculinized
Behavior: male normal, female no lordosis
Mother offspring with low dose: males and females normal
Behavior: male normal, female normal lordosis
SRY gene
200 AA, Sex-determining region on Y-chromosome (= testes present)
SRY encodes for testes
If SRY is present, testes and androgens will be present; if no SRY is present, no testes present
No SRY present will lead to a decrease or lack of hormones, leading to ovary differentiation
XX
- genotypically female, phenotypically female (ovaries)
XY
genotypically male, phenotypically male (testes)
XX^(SRY)
genotypically female, phenotypically male (testes)
XY ^(-)
genotypically male, phenotypically female (ovaries)
Explain difference between XX and XX^(SRY)
hormone difference
What is difference between XY^(-) and XX
genetics difference
SDN-PoA
Stands for Sexually dimorphic of pre-optic area
Roger Groschi did experiments in relation to this
Rat hypothalamus, pre-optic area (PoA); SDN-PoA larger in one sex of rodent over another
Rat Experiments done by Roger Groschi
Castration: done to rats at early age, had a small SDN-PoA; rats had no mounting behavior
Injected females with testosterone: had large SDN, PoA; rats had no lordosis behavior
Note: testosterone gets coverted to estradiol in the rodents, so estradiol is really creating this affect! They just did not know this at the time of the study
Injected females with estradiol: had large SDN-PoA; rats had no lordosis behavior
Effects of hormones on development in mammals
Body development gential hormones
Male: androgens (testosterone + dihydrotestosterone)
Female: lack of hormones
Brain hormones
Male: estrogens, androgens, combo of both
Female: lack of hormones
Adult sexual behavior:
Male: androgens, estrogens
Female: estrogens, progestines
Body development genital hormones and brain hormones organizational effects, adult sexual behavior activational affects
Effects of hormones on development in Japanese Quail
Body development gential hormones
Male: lack of hormones
Female: needs estrogens
Brain hormones
Male: lack or hormones
Female: estrogens (feminize)
Adult sexual behavior:
Male: androgens, estrogens
Female: estrogens, progestines
Body/genitals and brain organizational affects, adult reproductive behaviors activational effects
Song system in Zebra Finches
Neural Song Circuit: 4 different sections, Sections larger in males compared to females
Experiments show Area X in males and not females(but does not mean it isn’t there)
Effects of hormones and genetics on the development of the song system in zebra finch
Testosterone has aromatase to create estradiol and 5 alpha-reductase to create DHT(dihydrotestosterone, more potent androgen)
In males, the gonads have a lack of hormones and testes; In females, the gonads have estrogens for ovary development
In male brains, hormone manipulations did absolutely nothing
In females, hormone manipulation by E2 causes masculization partially under a abnormally high does of estradiol; this causes song production and behavior
In females, DHT/DHT +E2/Testosterone create absolutely no reaction
