Lecture 10

Question 1

sex

Answer 1

condition, property, or quality by which organisms are categorized as female or male on the basis of their chromosomes, hormones, reproductive organs, and other morphology, as well as behavior

Question 2

sexual behavior

Answer 2

actions directed towards reproduction (bringing the gametes together), also called mating or copulation

Question 3

male sexual behavior

Answer 3

all the behaviors necessary and sufficient to deliver male gametes to female gametes

Question 4

two overlapping processes of MSB

Answer 4

1. sexual motivation
2. sexual performance

Question 5

sex drive

Answer 5

powerful motivational forces propelling individuals to seek copulation (aka libido)

Question 6

male rats with more MSB experience castrated

Answer 6

sex behavior decline following castration much more varied

Question 7

younger rats news to MSB are castrated

Answer 7

sex behavior disappears relatively quickly

Question 8

consummatory phase of male mating behavior

Answer 8

1. mounting
2. intromission
3. ejaculation

Question 9

mounting

Answer 9

assuming a copulatory position without inserting the penis

Question 10

intromission

Answer 10

the entrance of the penis into the vagina (during a mount)

Question 11

ejaculation

Answer 11

forceful expulsion of semen from a male’s body through the urethra

Question 12

rats typically have __ ejaculations during a sexual session

Answer 12

multiple

Question 13

copulatory lock

Answer 13

after ejaculation the penis swells, locking it in-place inside the vagina

Question 14

post-castration effects

Answer 14

MSB reduced, sex drive declines

Question 15

order in which MSB returns following testosterone treatment to castrated males

Answer 15

1. mounting
2. intromissions
3. ejaculations

Question 16

maintenance (castration)

Answer 16

testosterone treatment begins immediately following castration, no period of time in which animal completely devoid of testosterone

Question 17

restoration (castration)

Answer 17

a gap between castration and the onset of testosterone therapy, period of time in which animal is devoid of testosterone

Question 18

what hormones can maintain MSB in castrated males

Answer 18

testosterone and androstenedione

Question 19

effect of aromatase inhibitor on MSB

Answer 19

reduces MSB

Question 20

DHT + estrogen

Answer 20

restores mating behavior

Question 21

decerebrate rats show erections with appropriate stimulation

Answer 21

don’t need CNS input to be able to show penile reflexes

Question 22

erections post-castration

Answer 22

disappear, hormones acting in the periphery to mediate the ability of the penis to show these reflexes/erections

Question 23

POA (pre optic area)

Answer 23

essential for sexual performance, stimulating MPOA accelerates ejaculation, integrating and processing sensory information (auditory, olfactory, tactile)

Question 24

castration reduces neural activity in the __ but not the __

Answer 24

MPOA, OBs

Question 24

vomernasal organ (VNO)

Answer 24

sensory receptive organ at the base of the nasal cavity

Question 24

olfactory bulb

Answer 24

receives input form olfactory sensory cells in nose, very large in rate brain ~12% of total brain volume

Question 25

lesions of the basolateral amygdala

Answer 25

reduce sexual motivation but do not affect consummatory behaviors

Question 26

lesions of the corticomedial amygdala

Answer 26

increase ejaculation latencies, abolishes copulation behaviors in hamsters

Question 27

sensory input from an estrus female evokes DA release from 3 dopaminergic tracts

Answer 27

1. nigrostriatal tract 2. MPOA 3. mesolimbic tract

Question 28

nigrostriatal tract

Answer 28

largest dopaminergic system and mediates the initiation of movement, important for muscle movements required for mounting

Question 29

MPOA

Answer 29

microdialysis studies show DA release in MPOA for female, but not food, or male rats

Question 30

mesolimbic tract

Answer 30

important for reward and appetitive behaviors, blocking DA receptors in the nucleus accumbens reduces sexual motivation

Question 31

partner novelty: The Coolidge Effect

Answer 31

sex behavior can be reinitiated if a new partner is provided, male rat will mate to satiation; if a new female is introduced the male will immediately resume copulation

Question 32

physical space

Answer 32

the interval between and pacing of intromissions, typically females control the pacing which allows them to match the pace for optimal reproductive efficiency

Question 33

classical Pavlovian conditioning

Answer 33

1. exposed to wintergreen odor 2. conditioned with wintergreen-estrus female pairings 3. when again exposed to wintergreen these mice show elevated LH and testosterone 4. similar hormone levels to an unconditioned mouse exposed to a female

Question 34

conditioned place preference (CPP)

Answer 34

a learned behavior that occurs when a subject comes to prefer one place more than others because the preferred location has been paired previously with rewarding events

Question 35

castration leads to

Answer 35

incredibly low libido in animals

Question 36

what level of libido does testosterone therapy bring animals to post-castration?

Answer 36

the same level that they were at to begin with, suggests that it's not the amount of hormone circulating governing libido

Question 37

how much testosterone needs to be circulating to restore MSB?

Answer 37

a very small amount of testosterone is needed to see very significant MSB, suggests global amounts of circulating testosterone not driving individual differences in libido/sex drive/amount of sex behavior seen

Question 38

high testosterone does not equal

Answer 38

high sex behavior