L2- Reproductive Behaviour, Libido & Control Flashcards
natural reproduction depends on ?
interaction between individuals of species.
reproductive success may depend on ?
age + engaging in sex
- libido
- engaging in sex enough times.
sex roles are a product of (3)
biological nature
- perception of this nature
- presentation of sexuality to others
what is biological sex?
determines anatomical + physiological “femaleness” or “maleness”
XX = ovaries, female accessory sex structures, female 2-ary sex characteristics
XY = testes, male accessory sex structures, male 2-ary sex characteristics
biological sex + brain function
- hormones present during brain development shape how the brain forms.
- also shapes sexual behaviour
what id gender identity
psychological perception of one’s biological sex
- personal experience,
- not necessarily lines up with biological sex
- not static, and not necessarily binary
what are sex roles?
outward expression of gender identity
- presentation thru behaviour
what influences are on sex roles + gender identity?
culture, social interactions, home/family enviro, religious beliefs, biology
= nature vs nurture
what is sexual reproduction?
interaction of two distinct sexual organisms
- sexual process: implies specific + complex affinity btw individuals of the opposite sex
human sexual behaviour encompasses a wide range of activities: (3)
strategies to find + attract partners
- chemical interactions btw individuals
- physical interactions during sexual intercourse : neuro-endocrine intxn - ANS influences repro
ensuring copulation -need what?
make fusion of gametes possible
- facilitate sperm entry into female repro tract
- fertilize ovum
key aspect in sexual function?
sexual desire : interest in engaging
physiology of sexual connections
- 3 types
- made by?
physical, chemical + informational connections.
- made by emitting + receiving physical + chemical cues from individual.
3 emotional categories for mating + reproduction?
- lust (libido/sex drive)
- attraction
- attachment
each assoc with particular pattern of neural activity + evolved to control aspect of repro
Lust
- what is it?
- leads to?
= craving for sexual gratification
- motivational
- leads to initiation of sexual activity + procreative behaviour
Attraction
lust facilitates attraction.
- preference for certain traits exhibited by potential mate
- increased energy + focused attention on potential mate that is worth the cost (energy, time, viability)
attachment
maintain close social contact
- recognizing, preferring + maintaining proximity.
how three emotional categories evolved nowadays?
more independent of each other.
- can interact, but dont have to be tied for successful repro.
what is human mating flexibility?
separation of the three emotional categories.
- widen contemporary human mative + repro strategies
behavioural variation
distribution of brain sites, hormone, and NT receptors assoc with each emotion category varies btw + within species, and within person over time.
examples of behavioural variation
- individual variation of sex drive among humans
- individual variaitons in frequency + duration of human attraction
- individual variation in human attachment
other impacts behavioural variation
- cultural + ecological.
* may have neural correlates*
sex drive as an intrinsic, natural phenomenon
- implications of it?
- evolved to drive ppl to engage in sex
- thought to arise intrinsically around sexual maturity
- gave ppl pleasure in sex (not found in other animals)
- duration + frequency of human sexual encounters exceeds that of other animals
how is sex drive a multidimensional phenomenon?
many mammalian aspects of anatomy + physiology involved
- modulated by ecological stimuli, olfactory cues, learning
what hormones are associated with sex drive/lust?
androgens + estrogens
what happens if lust is impaired?
asexual , may not want to engage.
- initiation becomes a problem.
sex drive mediated by what?
median preoptic area of anterior hypothalamus
MPOA regulates?
ALL motivated, goal-directed behaviour required for survival of individual + species
MPOA is source of?
GnRH . stimulates sex steroid production
lesion of MPOA =?
first observed in male guinea pigs.
- disrupts male sexual behaviour in all vertebrate species studied.
- disrupts appetitive behaviours
what are the appetitive behaviours in rats?
motivational behaviours - particularly sequences + timed.
- hop + darts around female rat
- female lordosis
Male rats - sexually rewarded maze learning.
MPOA damage?
x-maze, sexually receptive female in one arm.
- MPOA damage: olfactory cues will be ignored + male wont seek out female.
castrated male + ovariectomized female rodents -
- replace with A?
do not exhibit sexual desire. ]
- no T
- DHEA not enough to support repro fxns
- if replace with A: normal sex fxn. increase dose = increase libido
T related to sex drive - evidence?
elevated T (in M or F) = increased sex drive.
- T converted to E, so maybe E has effect on sex drive.
circulating T in young human males : STUDY
measured circulating T and time spent viewing erotic stimuli.
- more T = more time spent viewing erotic image.
- higher T = higher sexual motivation
circulating T in young males : STUDY - implications
- strongly predicts sexual motivation + behaviour
- directly implicated in increased interest in sexual visual stimuli
where do steroid hormones act when sexually relevant stimulus?
- steroid hormones act centrally + peripherally = more likely to elicit sexual response
sex hormones affect other hormones how?
modulate central neurotransmitter release: prime brain to be more receptive to sexual stimuli.
- DA increase?
- act in MPOA of hypothal.
MPOA and other senses
MPOA uses sex hormones to prime sensory processing to favour sexually relevant stimuli.
DA signalling in MPOA
- inject DA antagonist = decreased sexual motivation
- DA rises in pre-copulatory period - indicating role in sexual motivation.
T interaction with DA - found in male rats
T presence required for DA increase = permissive effect on DA release.
study in male rats on DA.
- intact
- castrated with T supplement
- castrated + vehicle (1 week)
- castrated + vehicle (2 weeks)
what are 3 phases?
3 phases?
- baseline
- pre-copulatory: smell/sense female but can’t get to her
- cop: male makes contact with female - usually engage in sex, ejaculates 6-8 times a session.
study in male rats on DA.
- intact rats response
- pro-cop: detect F, DA increase in MPOA.
- continually increase, active process of DA increase. if in pre-cop for too long, DA with decrease. need cop
- cop: successful mating many times
study in male rats on DA.
- cast + T
- supplemental T rescues sexual motivation. performance worse than natural but still increase in DA thru phases
study in male rats on DA.
- Cast + Veh 1 week
no T because testes were removed.
- still see increase in DA throughout pre-cop + cop.
- circulating T not found, but T has long lasting effect.
- found for E too.
implications from study in male rats on DA. re: cast + vehicle 1 week.
priming of T on MPOA is longer lasting, has residual effect.
study in male rats on DA. - cast + 2 weeks vehicle
No T, remove testes
- no more circulating T, all positive + long-lasting effects have diminished
- no rise in DA during pre-cop.
- similar results as when lesion MPOA, remove T or prevent DA
anti-depressants on libido
side effects of SSRI = supress libido.
- where DA stimulates, 5-HT supresses
what NTs are associated with attraction?
catecholamines + DA
what characteristics make a preferred partner
physical symmetry
- display of resources
- display of fertility
- display of health
attraction in humans vs animal models
animals = attraction is fleeting
- humans: attraction is longer + higher intensity
romantic attraction appears in brain how?
- mesolimbic area (reward centre)
- - increased monoamine NT: DA, NA
some effects of DA
euphoria, loss of appetite, hyperactivity, increased mental activity, decreased need for sleep.
- heightened motivation + goal-directed behaviours
- most likely assoc with increased passionate attraction
higher order cogniton involved in attraction - why?
over-ride who/what we are attracted to.
- other factors influence: culture, family expectations, childhood experience
what does attachment look like?
species-specific touching, separation anxiety when apart, attempting to restore close contact after separation
- form “pair bonds”
what hormones are associated with attachment?
vasopressin + oxytocin
- V: usually think about water reabsorption, renal stuff
- O : childbirth, uterine contraction, pair bond with partner/child
attachment evolved why?
- attachment related to?
evolved to motivate individuals to engage in positive social behaviours (stick close to bb - give them a chance)
- assume species-specific parenting behaviours
- associated with consummatory actions
- not necessarily related to attraction or sex drive
vasopressin + oxytocin
- mediator of what?
- produced by?
highly conserved mediators of social cognition + behaviour
- produced by neurons in SON and PVN, released from post pit thru neuro-circulatory connection with hypothal.
-
extra-hypothalamic sites for V production
- act on pre-frontal cortex and modulate behaviour
- develop in greater numbers in males compared to females
neurochemistry of the paid bond
- study of prairie voles + O
Ctrl females: spend more time with partner than with stranger.
O antagonist + O = same as control
O into brain = when physiologically relevant does, F spends more time with mate of choice, less with stranger
O injected peripherally = dont see marked effect in facilitation of pair bond.
V and pair bond in males
F => O
M => V
male prairie voles + V study
- block V
anti-V: less time spent with partner and more time spent with stanger.
suggests V is important for male pair bonds
- V more responsible for pair bond than O
O receptors found where?
nucleus accumbens + PFC
monogamous behaviour in males asosc with?
increased V in ventral pallidum
O + V implications for humans from info on rodents?
- roles difficult to discern
- increased O after male orgasm
- increased V during sexual arousal
- sex may not be essential for bond formation but may facilitate.
young male humans. blood samples of O+V
- findings?
- arousal: V not much higher than baseline. higher O in/after orgasm.
