Development of behavior part 2

Question 1

Critical period

Answer 1

window of time when hormones creating affect, 2 periods

Question 2

2 periods of Critical period

Answer 2

Organizational and Activational

Question 3

Organizational period

Answer 3

early (pre-natal or peri-natal), permanent affects, changes to neural and muscular structures

Question 4

Activational period

Answer 4

later in life (juvenile or adults), transient, activate neural and muscular structures that were previously organized

Question 5

Lordosis

Answer 5

arched back presented in female rodents during sexual reproduction (measured on scale in experiments)

Question 6

Bipotential gonads

Answer 6

SRY present = testes, adrogens

SRY absent = no testes, ovaries, lack of hormones

Question 7

Alpha-fetoprotein

Answer 7

blocks estradiol and prevents overproduction from entering brain of organism; androgens bypass it

Question 8

Why aren’t females PoA masculinized by their own estradiol?

Answer 8

Females not producing many hormones before puberty

Females have low estradiol during critical organizational periods when SDN-PoA forms

Alpha-fetoprotein blocks estradiol

Note:
Male androgens bypass alpha-fetoprotein; Parts of male brain masculinized by adrogens, estrogens, or combo of both to express certain behaviors

Question 9

What is responsible for normal development of the zebra finch song system?

Answer 9

Auditory learning and social interaction

Question 10

What are the behavioral and SDN-POA effects of treating female rats with T? With E2?

Answer 10

Same reactions(since testosterone can be converted to estradiol), had no lordosis behavior occur

Question 11

What are the behavioral and SDN-POA effects of castrating male rats?

Answer 11

No mounting behavior occurs

Question 12

What enzyme is necessary to produce DHT? E2?

Answer 12

Testosterone has aromatase to create estradiol and 5 alpha-reductase to create DHT(dihydrotestosterone, more potent androgen)

Question 13

What does the ovo-testis experiment tell us about the role of hormones in the development of the zebra finch song system?

Answer 13

E2 has a big involvement individually in song development/masculinization

Hormone manipulations to males did nothing at all

Question 14

What hormone is necessary for ovarian development in birds?

Answer 14

estrogen

Question 15

Why is the α-fetoprotein important for normal development in female mammals?

Answer 15

it binds to estrogen, prevents estrogens from masculinizing the development of brain (shield)