L7a_Brain Sex Differences

Question 1

Organizational effects

Answer 1

• long-term effect of hormonal action occurs during fetal development or prenatal
  -leads to permanent changes in behavior

Question 2

Activational effects

Answer 2

-hormonal effect occurs in adult animals
-cause a short-term change in the behavior

Question 3

Epigenetics (epigenetic regulation and inheritance)

Answer 3

• Epigenetics =epigentic regulation (permanent changes in gene expression; organizational effect)
• Information transfer from cell to cell or organism to organism
• permanent changes in gene expression could be common, but only a FEW are heritable

Question 4

Methylation

Answer 4

-methyl groups added to DNA
- reduce gene expression

Question 5

Acetylation

Answer 5

-acetyl group added to residue sticking from the histone core
- increase expression

Question 6

Histone

Question 7

SRY

Answer 7

the sex-determining region in Y chromosome
- transform undifferentiated gonad to a testes

Question 8

Endocrine disrupting chemicals (READ pgs 132-138)

Answer 8

-DDT had effects on sexual reproduction in birds
- Atrazine exposure caused testicular malformation in frogs

Question 9

Compensation (McArthy 2011)

Answer 9

Differences between male and female that is not due to sexual selection
-some effects occur to compensate (reverse) sexual differences

Question 10

Aromatase

Answer 10

the enzyme that converts androgens to estrogen

Question 11

Kisspeptin

Answer 11

• in SCN
• enhance the release of Gn RHH from hypothalamus
  -in AVPV, kisspeptin are bigger in females

Question 12

Hypothalamus

Question 13

Preoptic area

Question 14

Medial preoptic area (MPOA)

Answer 14

• associated with male sexual behvior
  -larger in males

Question 15

Sexually dimorphic nucleus of the preoptic areas (SDN -MPOA)

Answer 15

• larger in males (rats)

Question 16

Interstitial nuclei of the anterior hypothalamus (INAH 1&3)

Answer 16

• in MPOA (forger 2016)
• larger in males
• most dimorphic
  - males more neurons, different connectivity, and rich androgen receptors
  
  • apoptosis without androgens (or estrogens)

Question 17

Suprachiasmatic nuclei (SCN)

Answer 17

• in hypothalamus
• larger in females(biological clock)

Question 18

Amygdala

Answer 18

• aggression and threat responses

Question 19

Bed nulceus of the stria terminals (BNST)

Answer 19

• larger in males

Question 20

Dendritic spine

Question 21

AVPV

Question 22

Midshipman (online article)

Answer 22

Midshipmal with pacemake neurons
Type I males hum and Type II very small

Question 23

11-ketotestosterone

Answer 23

• produce by only type I males and effective in stimulating the development of sonic musculature and neural activity

Question 24

3 main mechanisms for epigenetic regulation

Answer 24

• DNA methylation
• Histone Methylation
• Histone Acetylation

Question 25

How hormones can change the brain?

Answer 25

1. affect abundance and distribution of receptors
   -methylation of estrogen receptors
   
   • estrogen receptor knockout is complicated
   • AR knockout reduces sexual behavior and aggression in male rats
2. affect the density of neurons in different areas
   
   • MPOA (large in males) and SCN (large in females) are most different
   • MPOA with epigenetics (females + expression turn to more male)
   • Amygdala and BNST large in males
   • BNST size and epigenetics (VPA increases acetylation and gene expression for apoptosis! so females are larger in acetylation compared to males (male +expression turns more than females)
   • more expression cause the reduced size
3. affect connectivity
   - MPOA females on spines and males of shafts
   - SCN with kisspeptin