Chapter 6

Question 1

Female Sex Behavior: Hampsters

Answer 1

big behavioral challenge
- when hormones regulate female behavior, there are variations

• hampsters smell each other to see if the female is in reproductive state
• if the female recieves or experiences high levels of estrogen and then progesterone, it will do mating behavior
• if not exposed to estrogen, she will kick and bite male

Question 2

Rats and Puberty

Answer 2

puberty is at day 40
- post pubtery = day 50 and on
- puberty timing in rats happens in a few weeks

Question 3

Kisspeptin and Pubteral Initiation

Answer 3

male and female behaviors is predicted by circulating hormones and by exposure or lack of exposure to hormones
- testosterone surge causes masculinization/defeminization

• females get low levels of hormones
• puberty happens, then they get more sexual behavior

Question 4

Regulating Puberty

Answer 4

GnRH is needed to trigger puberty
- then release of FSH and LH
- GnRH neurons need to be switched on

kisspeptin switches on puberty:
- kisspeptin amino acid staining in hypothalamus shows cells and fibers in the arcuate nucleus
- Kisspeptin develops and then around day 35 in rats, it goes up
- Kisspeptin accelerates and turns on GnRH

Pubtery Accelerator: AVPV starts expressing a lot of kisspeptin which activates GnRH

Question 5

Kisspeptin Mutations in Humans

Answer 5

study showed 8 kids and 5 of them failed to go thru puberty
- each of the kids have mutations in the kisspeptin or ligand receptor

***supports the belief that kisspeptin is important for starting puberty (in humans and in rodents)

Question 6

Central Precocious Puberty

Answer 6

early puberty triggered by the system
- this is because of an activating mutation of the kisspeptin receptor gene

• kisspeptin becomes overactive and triggers puberty very early on in life
• you then give that person a block to pause puberty and then that allow that person to return to puberty once they get older
• once puberty is triggered, FSH and LH rise

Question 7

Female Rats in Estrous Vs. Not

Answer 7

females allow male rats to approach them if they are in estrous (reproductive state)
- they won’t allow them to if they aren’t in estrous

estrous females:
- seek out males
- males make more effort to be closer to female in estrous
- they initiate copulation
- more attractive to males than anestrous females
– pheromone cues or behavioral cues that the estrous female will signal to the male to approach them

*males will attempt to mount an anestrous female rat, but then they will stop because the female won’t tolerate it

Question 8

Change in Estrous Behavior

Answer 8

the change in estrous behavior is correlated with ovulation
- they want mating to occur around time of ovulation for fertilization to happen

• hormones change motivation and perception of male and females
• they have touch receptors

***male sex behavior is more consistent (don’t have to wait for them to be in estrous state) than females

Question 9

Lab Tested Female Rats in Estrous

Answer 9

the lab tested females every day
- they found on every 4th day, the female tolerates the male and engages in sexual behavior
- the next day, this behavior stops

• on the 8th day, the female tolerates the male again and engages in sexual behavior
  ***4 day cycle

Question 10

Ovary Influences Sexual Behavior

Answer 10

the ovary secretes hormones which changes behavior
- if you remove the ovary, the behavior stops
- they search the ovarian extract and wanted to know what was in it that regulated sexual behavior in rodent

*female engaged in sexual behavior when the substance had estrogen in it
-estrogens were first steroid hormone to be isolated
- progesterone came later as a supplemental factor (less people study progesterone)
*progesterone with estrogen can help induce estrous state

Question 11

Sexual Behavior - Estrogen and Progesterone Cycle

Answer 11

sexual behavior in rodents occurs on 4th day of cycle
- days before, estrodial and estrogen increases for 2 days, then it drops
- around the time of ovulation, there’s a surge of progesterone

***need precise timing of estrogen followed by progesterone (24-48 hrs after)

Question 12

Light and Dark Cycles

Answer 12

they are nocturnal
- engage in estrous behavior during dark phase
- measure hormones and see estrogen levels go up
- just before the lights go off, progesterone levels spike, then within 4-6 hours, estrous behavior occurs

Question 13

Removing the Ovary

Answer 13

if you remove the ovary after the release of estrogen and progesterone, and you oyvex, within an hour or so, the female will engage in sexual behavior

• removing the ovary doesn’t change sexual behavior if they still get the hormone
• if you remove the ovary after estrogen release, you put back progesterone, it will engage in high levels of sex behavior

***animal needs to see estrogen and progesterone to have sexual behavior

***if you remove the ovary before progesterone and don’t supplement with progesterone after, it blocks the behavior

Question 14

Hormone Regulation of Female Sexual Behavior

Answer 14

no hormone –> no levels of sexual behavior

estradiol followed 2 days later by oil –> little to no levels of sexual behavior

estradiol followed by 2 days later by progesterone –> high levels of lordoisis

Progesterone followed 2 days later by estradiol –> little to no levels of sexual behavior

• if you ovex the animal, no hormones, no sex behavior

Question 15

Order of Estrogen and Progesterone is Important

Answer 15

when animal gets estrogen, it goes to brind, binds to receptors and activates genes (feeding, disease, etc)

ex: estrogen increases progesterone receptors in the brain

• estrogen binds to receptor, initates DNA, which increases progesterone receptors (when progesterone surge happens, it now can bind to receptors to activate sexual behavior)

oil treated:
- remove ovaries: very few progesterone recpetors in the brain
- if you inject estrogen, wait 2 days, you see a lot of progesterone receptors in the brain

Question 16

Estrogen and Progesterone Recap

Answer 16

if you ovex animal and give progesterone, no female sex behavior bc there’s no progesterone to bind to (estrogen needed to generate progesterone receptors)

• estrogen needs to come first to make the progesterone receptors

*people with high levels of testosterone - it gets aromatized into estradiol which then makes progesterone receptors (lots of them)

***people with high levels of estrogen or high levels of testosterone will then have high levels of progesterone receptors

Question 17

Parts of Female Sexual Behavior

Answer 17

Attratcivity: stimulus value of female
- will the male approach the female

proceptivity: the extent of if the female will engage in copulation
- female sex behavior

receptivity: lordosis
- reflex of behavior

Question 18

Attractivity

Answer 18

uses 3 chambered task
- females are restrained to diff chambers
- if you put the male in the center and measure where it goes, it will go to estrous chamber

• if the male goes to anestrous chamber, the female will attack the male and kick it out

*female more attracted to the male to be in the chamber with it (estrous female)

Question 19

Masculine vs. Feminine Faces

Answer 19

women in follicular phase, are more attracted to males with masculine faces
- if you show these faces during the follicular phase, the bushier eyebrows is sign of masculinity and wider neck
***these masculine traits are prefered in follicular phase

• in Luteul phase, the more feminine face are prefered

Question 20

Ovulation Timing

Answer 20

ovaries are actively secreting hormones around ovulation time
- in humans the hormones move too

***the number of sexual desires being increased is timed with ovulation
*the higher it is, the closer they are to ovulation

*androgens are also important to sexual desire in women

Question 21

Proceptivity

Answer 21

behaviors shown in females

Proceptivity: measured by
- influences by progesterone
- approaches
- investigation of males anogenital region
- ear wiggling
- hop-darting (jump and then dart, then stop and wait, then wrestle)
- mounting of male

Question 22

Receptivity

Answer 22

reflects sexually receptive posture of the rat for mating with a male

• reflexive in rodents
• females arch their back when mounted by a male rat
• they rank the arch
• hormones are predictive of the intensity of the behavior (arch)
  ***those that are slightly in reproductive state do less of an arch
• those with more (like 3 points) do more arching

*they have to show lower doses for male
- female controls this sexual behavior

*most social contacts between males and females before copulation are intiated by females

Question 23

Pacing Mating on Fertility

Answer 23

ability to escape even in lab condition can alter the probability of the female becoming pregnant

• chamber with divider (use larger male or older male)
• there’s a hole
• the female can come into the chamber and leave, but the male is too big so it can’t leave (male can’t chase her)

*called pacing chamber because female can pace the sexual encounter

Question 24

Pacing Chamber: Divider or no divider

Answer 24

almost 80% of those in the paces condition become pregnant
- once the male does 5 mounts, you remove the male and see if the female got pregnant

*huge difference in pregnancy rates with divider or not

Question 25

Lordosis and Touching

Answer 25

lordosis = female arching of back - if male touches the back region of female rat - if female doesn't show arch, no intromissions will occur - if female has estrogen and progesterone, the back will arch where intromission (sex) will occur

Question 26

Estrogen Exposure and Touch Receptors

Answer 26

***exposure to estrogen can change receptor fields in the skin to touch - if female doesn't have estrogen, the area the male will touch is small - if the female is given estrogen, the touch field is a lot bigger *if touched in the field, the female will do lordosis ***estrogen is more involved in receptive behavior ***progesterone is more involved in proceptive behavior

Question 27

Male Mounting and Touch Receptors in the Brain

Answer 27

when the male mounts, the touch sensory fields feel it - then that touch goes to the hypothalamus, and then the circuitry is gated by hormone presence - if hormones act in both places, sends signal for reflexive arch to happen `

Question 28

Estrogen Receptors in Rat Brain

Answer 28

estrogen receptors influence many parts of the brain, including the hippocampus - estrogen influences cognition but not a lot ***there's high amounts of estrogen in the preoptic area in the hypothalamus

Question 29

Estrogen Injections in the Brain

Answer 29

if you only injected estrogen into the hypothalamus and ovex the female rat, then you will get low levels of female sex behavior (receptive behavior) ***estrogen increases progesterone receptors - you only need the ventromedial hypothalamus (VMH) for female sex behavior to happen estradiol goes into VMH which causes lordosis - estrogen binds to the ER and VMH to make progestin receptors - then estradiol goes into the VMH with progesterone injection causing full lordosis *if you disrupt estrogen or progestin receptors in the VMH, the female will have disrupted female sex behavior

Question 30

Mice that Lack Progesterone Receptors

Answer 30

if mice lacks progesterone receptors, then they won't show sex behavior - wild type animal shows high levels of female sex behavior (80% of the time they will show sex behavior if they are given estrogen and progesterone) - heterozygous (have half amount of progesterone receptors) have high levels of lordosis like the wild type kind - knockout mice (no progesterone receptors) show no to little lordosis

Question 31

Sexual Behavior Activates Reward System

Answer 31

the ovary secretes estrogen and progesterone for ovulation - the reward system drives this - tactile stimulation goes into the brain, and then the brain will send out signals to make the arch (lordosis) 1. sexual signals - maybe pheremones 2. the odor goes into the olfactory circuits 3. tactile stimulation from the male (mounting) 4. female does lordosis 5/6.vagina opens 7. reward system activated (Nucleus Accumbens and Ventral Tegmental Area)

Question 32

Dopamine Pathway

Answer 32

- in the midbrain, there's the ventral tegmental area - the cells go into the nucleus accumbens -*the accumbens is the brain's reward center (has lots of opioid receptors) - anything that is rewarding prob is connected to accumbens area Nucleus accumbens: - involved in sex behavior, addiction, feeding - different areas project to it - amygdala projects to it to get social reward circuit ***the accumbens gets the reward to the systems and reinforces them ***sexual behaviors increase dopamine

Question 33

Measuring Dopamine Release

Answer 33

the nucleus accumbens is active during sexual behavior - if you put a tube (microdialsis) in the brain, it pushes fluid and comes out **this samples what is in the accumbens - it's like a straw that pushes a little liquid in and then back out *measuring dopamine release

Question 34

Paced Situation and Dopamine

Answer 34

if you pace mating to see if dopamine is released in the nucleus accumbens sample: - in unpaced sample: very little increase in dopamine paced situation: big increase in dopamine - pace situation is more rewarding to females - female has more control of situation - female is also more likely to get pregnant during the paced situation

Question 35

Conditioned Place Preference

Answer 35

has post-pubertal rats in an arena - female has to have estrogen and receptors, then it goes by itself - if you take the rat out, it will prefer the arena where sexual behavior happened