Exam 3: Reproductive Behavior : Sex Part 2

Question 1

pheromones

Answer 1

chemical signals that communicate between animals
- female mice can identify individual males by pheromones in urine
bruce effect

Question 2

bruce effect

Answer 2

pregnancy termination due to pheromones from a different mate

Question 3

vomeronasal organ (VNO)

Answer 3

specialized receptor cells in nose that detect pheromones (not odors)

Question 4

VNO axons go to accessory olfactory bulb which projects to the _____ and ____

Answer 4

medial amygdala (mPOA) and hypothalamus (VMH)

Question 5

mPOA or VMH integrates what?

Answer 5

hormonal and sensory information and coordinates motor patterns of copulation
- connection between smell and amygdala

Question 6

female sex behavior needs to be…

Answer 6

turned on

it is off unless turned on

Question 7

ventromedial nucleus of the hypothalamus (VMH)

Answer 7

essential for sexual behavior in females (lordosis response)

Question 8

VMH afferents

Answer 8

vomeronasal organ (pheromones) and somatosensory system via amygdala

Question 9

estrogen increases…

Answer 9

dendritic trees of neurons in VMH and stimulates production of progesterone receptors

Question 10

what happens when VMH gets more dendrites

Answer 10

the system is more sexually receptive

Question 11

VMH sends axons to the ____ which projects to the ____

Answer 11

periaqueductal gray in midbrain

medullary reticular formation (NPGi)

Question 12

How does NPGi project to spinal cord

Answer 12

reticulospinal tract

Question 13

What needs to happen to initiate sex in males

Answer 13

remove the brakes, needs to be disinhibited

Question 14

What coordinates male copulatory behavior

Answer 14

medial preoptic area of hypothalamus (mPOA)

Question 15

afferents of medial preoptic area of hypothalamus

Answer 15

vomeronasal organ (pheromones) and somatosensory system via amygdala

Question 16

mounting behaviors

Answer 16

• mPOA sends axons to ventral midbrain
  
  • excitatory dopamine signals from substantia nigra synapse on neurons in basal ganglia
  • basal ganglia output neurons send excitatory signals to spinal cord to induce mounting

Question 17

ventral midbrain composed of

Answer 17

PAG and substantia nigra

Question 18

which pathway leads to copulation

Answer 18

going through the substantia nigra pars compacta

Question 19

which pathway leads to erections

Answer 19

PAG to NPGi

Question 20

Paragigantocellular nucleus (nPGi)

Answer 20

in medullary reticular formation
has axons fibers that inhibit the erection response
- serotonin

Question 21

2 route to shut down the nPGi

Answer 21

direct and indirect

Question 22

direct pathway to shut down the nPGi

Answer 22

mPOA inhibits nPGi inhibition of sexual behavior

Question 23

indirect pathway to shut down nPGi

Answer 23

via periaqueductal grey
PAG normally excites nPGi preventing erections
mPOA neurons inhibit PAG thus inhibiting nPGi

Question 24

lesions of mPOA

Answer 24

do not interfere with male’s motivation for copulation

• they will still press a bar to gain access to receptive female but they seem unable to commence mounting
• cannot control erections

Question 25

sex-related function associated with the reward system

Answer 25

triggers sexual motivation mate choice mesolimbic dopamine

Question 26

prefrontal cortex function associated with sex-related functions

Answer 26

blunts initiation of sexual behavior modulates sex drive - judgement and decision making - changes levels of consciousness

Question 27

sex-related function associated with cingulate cortex

Answer 27

processing sexual stimuli in conflictuary contexts modulates sexual drive - detects conflicts

Question 28

sex-relation function of insula

Answer 28

awareness of tumescence of erectile organs modulates sex drive - regulates body states

Question 29

Parts of basal forebrain active in sexual behavior

Answer 29

nucleus accumbens - implicating reward system

Question 30

what suggests alteration of consciousness during orgasm

Answer 30

increased act9ivation in orbitofrontal cortex and anterior cingulate

Question 31

4 behaviors rat mothers show

Answer 31

nest building, crouching over pups, retrieving pups, nursing

Question 32

What plays a role in maternal behavior

Answer 32

anteroventral periventricular nucleus (AVPV) and mPOA

Question 33

what did the lesions of the MPA disrupt

Answer 33

both licking and pup retrieval - mothers ignored offspring - female sexual behavior was unaffected

Question 34

What regions are activated during parental care

Answer 34

ventral tegmental area motivation and reward center is activated - caring for offspring feels good

Question 35

male interaction with infants is influenced by..

Answer 35

hormonal changes - reduced testosterone levels during fatherhood (more time spent with child - greater decline in testosterone) - increased prolactin levels in males after becoming fathers

Question 36

what happens with increased prolactin levels in males after becoming fathers

Answer 36

- highest during infantile period and positively correlate with caregiving - more responsive to infant crying

Question 37

mPOA

Answer 37

- lesions lead to less parenting behavior | - optogenetic activation of mPOA neurons in virgin males suppresses pup-directed aggression and increased pup grooming