BE Exam 2 Flashcards
(144 cards)
1
Q
female repro behavior
A
all behaviors necessary and sufficient to achieve fertilization of femal gametes (ova) by male gametes (sperm)
2
Q
estrus
A
stage where females are in heat
3
Q
estrous females
A
motivated to seek males
4
Q
nonestrous females
A
not motivated to mate
5
Q
hormone action
A
hormones do not turn on behavior, they change prpobability that specific stimuli witll elicit particular behaviors
- affect input actuity, sensitivity, efficacy
- estrous females better able to detect and respont oconspecific males
- CNS: female motivation, attention, perception change as sex steroirs fluctuate
- output- hormones affect behavior and response to stimuli
6
Q
repro structures
A
- uterus, fallopian tubes, ovaries, cervix, vagina
-rat: uterus, foetus, ovaries
7
Q
uterine layers
A
endometrium, myometrium, serosa
8
Q
repro: hypothalamus anterior pituitary axis
A
-hypothalamus: GnRH to portal veins
- AP: FSH, LH to gen circulation
- Ovary: estrogen, progesterone to gen circulation
- to uterus, brain, other
9
Q
FSH
A
follicle stimulating hormone
- stimulates maturation of ovarian follicles
- follicle development= folliculogenesis
- before birth human female ovary contains peak number of follicles- 7 million
- can be dormant up to 50 years in human
10
Q
stages of follicular development
A
- primordial follicle
- early preantral follice
- late preantral follicle
-antral follicle
-pre-ovulatory/Graafian follicle, has liquid filled cavity- antrum
11
Q
oogenesis
A
development of ovum (egg)
- oogonium
mitosis - primary oocyte
meiosis 1 - secondary oocyte (polar bodies may divide and die)
meiosis II - ovum (polar bodies may divide and die)
- mature egg
- present by 3rd prenatal month
-become primary oocytes by month 6 - female born w all oocytes ever
-meiosis stops at prophase I and does not continue til puberty
12
Q
ovulation
A
release of ovum from follicle and ovary into fallopian tube
- induced by LH surge
- ovum released into body where is is (almost always) caught by fimbriae of fallopian tube led to uterus by cilia for fertilization
- then turns into diploid, to blastocyst (embeds on endometrium 6 days after fertillization), to fetus
13
Q
corpus luteum
A
after ovulation, follicle becomes yellow corpus luteum
-derives from granulose and thecal cells
14
Q
corpus albicans
A
degenerated corpus luteum
15
Q
determining stages of ovarian cycle
A
stockard and papanicolau
rodents: vaginal lavage
humans: pap smear
16
Q
cyclic changes in vaginal cell types
A
-nucleated epithelial cells: epithelial cells w nucleus, indicative of proestrus
- cornified epithelial cells: epithelial cells that lack a nucleus, filled w keratin, inidicative of estrus cycle
17
Q
estrous vs estrus
A
estrous- adjective
estrus- cycle
- an estrous female rat shows lordosis when in behavioral estrus
18
Q
cyclic changes and vaginal cytology
A
as the cell follicle develops, estradiol and progesterone secretes to get good lordosis behavior
19
Q
estrous cycle
A
- estrus: correlated w presence of recently ruprutred follicle following ovulation, and formation of corpora lutea
- diestrus I and II: development of new follicles
- proestrus” maximal follicular development, graafian follicle, behavioral estrus and mating occur
- external marker is disappearance of thin vaginal membrane
- vaginal estrus follows behavioral estrus
20
Q
ovarian steroids
A
influence behaviors corresponding w vaginal and ovarian cycles
- estradiol, progesterone
21
Q
estrogens
A
estrus generating substances
- synthesis and secretion depends on LH
- stimulates female sex behavior
- secreted from follicles
-rapid increase during day of proestru induced behavioral estrus and cornified vaginal epithelial cells
22
Q
progesterone
A
-secreted from Graafian follicle to stimulate behavioral estrus
- secreted from corpora lutea to prepare uterus for pregnance and maintain pregnancy (progestational condition= supportive of pregnancy, terminates behavioral estrus
23
Q
timing of estradiol and progesterone
A
- estradiol increase as follicle develops
- graafian follicle secretes P just before ovulation
- corpus luteum secretes P after ovulation
*estradiol induces formation of P receptors for lordosis behavior, E increases prior to P
24
Q
pulsatile release of GnRH from hypothalamus
A
-GnRH release
- FSH, LH release from AP
- follicles grow and release E and P
- E, P stimulate behavioral estrus, pos feedback
- surge of LH induces ovulation, E declines rapidly, P gradually, behavior terminated
25
corpus luteum
secretes P to maintain uterus during pregnancy
26
feedback on hypothalamus and AP
positive feedback
- prior to ovulation, rising E secreted from granulosa cells in ovary
- activin from granulosa cells stimulates FSH release
negative feedback
- after ovulation, elevated P from CL and E
- inhibin from granulosa cells inhibit FSH release
27
Activin and Inhibin
peptides
-secreted from granulosa cells
-activin: stimulates FSH synthesis and secretion
- inhibin: Inhibits FSH synthesis and secretion
28
estrogen feedback
estradiol acts on estradiol receptors in Kisspeptin neurons
- estradiol exerts pos and neg feedback effects on GnRH
- kisspeptin expressing neurons mediate both
- kisspeptin increases GnRH release
- estradiol acts differently on AVPV to stimulate GnRH release vs ARC inhibit Kisspeptin so inhibit GnRH release
pre ovulatory
- estradiol acts on kisspeptin in AVPV to exert pos feedback
post ovulatory
- estradiol acts on kisspeptin in ARC to exert neg feedback
- progesterone secreted from CL to hypothalamus and AP
29
woman vs rat ovulation
-similar: tight coupling between hormones and ovulation
- different: hormone independent sex behavior in humans vs tightly couples in rat
30
human menstrual cycle
- follicular phase: development of follicle
- luteal phase: development of corpus luteum, p from CP builds up in endometrium, low P in late luteal phase leads to menstruation
31
pseudopregnancy
when the body acts as if you are pregnant when you are not
- during luteal phase or when there is a functional CL and build up of endometrial uterine layer in absence of pregnancy
- uterus prepared for blastocyst implantation but has not fertilized ovum
- not normal part of estrous cycle
-CL continues to secrete P in absence of fertilized egg
32
female repro cycle type 1
Ovulation spontaneous
CL spontaneous
Cycle length 2-5 weeks, >5 weeks
human, monkey, hamster, dog
33
female repro cycle type 2
ovulation induced by mating
CL spontaneous
cycle lengh 3-5 weeks, >5 weeks
skunk, rabbit, cat
34
female repro cycle type 3
ovulation spontaneous
CL induced, not part of natural cycle
Cycle length < 1 week
rat, hamster, mouse
35
categories of sexual behavior
- appetitive
- consummatory
36
appetitive cat of sex behavior
actions that increase likelihood of mating to occur, thought to reflect sexual motivation
- approach, solicitation, investigation of potential mate
37
consummatory category of sex behavior
act of mating itself, hightly sexually dimorphic
- male: penile intromission, ejaculation
-female: lordosis posture
- mediated by distinct, overlapping neural substrates like
olfactory bulbs, amygdala, AVPV, PAG
38
frank beach
proposed idea of femal sex behavior in 3 components
- attractivity
-proceptivity
-receptivity
39
attractivity
stimulus value of a female for a given male
- morphological changes associated w ovulation ex. baboon welling of perineum
- vaginal secretions, urine
- behavior ex. flehman response
-someronasal organ detects pheromones ex. horse lift lip
- women in follicular phase attracted to more masculine males
40
proceptivity
extent to which female initiates copopulation; appetitive behavior
- reflects overt behavior and motivational state
- # of soliciations made prior to secual contact ex. rhesus monkey
41
receptivity
females state of responsiveness to sexual initiation by another; consummatory behavior
- reflects stimulus value of female for eliciting intravaginal ejaculation by male consepcific
- rat-lordosis
- hamnsters- amount of time spent in lordosis
42
rhesus monkeys
-attractivity measured as mounting ration (# mounts/min)
- proceptivity measured as amount of time female took to bar press to access male
- receptivity measured as # of ejaculations and time
- estrogen mediates proceptivity, attractivity, and receptivity in monkeus
- estrogen increases attractivity
43
male behavior
mounting
intromission
ejaculation
44
female rat mating behavior
solicitation- proceptivity
- tenseness
- hopping, darting
- ear wiggling
lordosis (receptivity)
- dorsiflexion
-lateral tail deflection
45
hormonal regulation of sex behavior in female rats
-ovariectomy= no receptivity, no proceptivity
- ovariectomy, E replacement 48 hrs before= weake receptivity, no proceptivity
- ovariectomy E + P replacement 5 hrs before= full receptivity, full prospectivty
- ER and PR needed for lordosis
46
E and P action
on VMH
- stereotaxic instrument for brain cannulation show
- bilateral E implants inVMH activate lordosis in rats w P
- bilateral anti-E implants in CMH reduce lordosis in rates w E and P
47
mechanism of estrogen action
- E, P synthesized w receptors, enzymes, transporters, ion channels, structural proteins etc
- to neuronal responsiveness influenced by male stimulation
- to electrical activity
- estrogen to muscarinic receptors (acetylcholine binds) in VMH
- neuronal responsiveness by male stimulation
- electrical activity
48
acetylcholine and lordosis
acetylcholine agonists increase lordosis in OVX rats primed w low E
- acetylcholine antagonists decreases lordosis in OVX rats w E and P
- lordosis regulated by muscarinic acetylcholine receptors
49
paradigms to study female rat sex behavior
- Ovariectomy (1 week)
- estradiol benzoate (2 days)
- P (5 hours)
- pretest for behavior
- administer drug
- test for behavior
50
hormone effects on neuronal morphology
- E treatment increased dendritic spine density in vmh
- dendritic spine density fluctuates across estrous cycle: higher during proestrus when E levels r high
- cell bodies dendritic length
51
receptive fields in flanks
increase in size during estrus, neural basis of lordosis:
- flank stimulation: sensory input to spinal cord ascent to hindbrain, midbrain
- E acts in hypothalamus- inputs to midbraing
- Central gray-ascending tracts to spinal motor neurons to deep back muscles leads to lordosis
52
neural circuitry mediating lordosis
- estradiol binds to ERs in hypothalamic nuclei, including VMN
-VVM neurons descend to MCG=PAG
- E receptor immunoreactivity in hypothalamus
53
paced mating
female controls copulation
- female controls interval btwn sex interaction
- interval depends on nature of sexual interaction
- vaginal code: optimal pattern of stimulation to produce offspring, species specific
- rewarding to female rats
54
behavioral results of pacing
-intervals btwn intromissions r longer
- females stay away from males after ejaculation longer- can discriminate typ of vaginal stimulation
- paced mating enhances reproduction
55
hormonal effects of paced mating
- paced intromissions
- prolactin release
- CL maintained
-P secretion
- pregnancy maintenance
56
testicular descent
7 months, testes descend from penile structure, need to be outside bc body temp is too hod
57
aggression and female sex behavior
- same social cue can induce lordosis or aggression depending on repro state of female
- dif ET- positive cell types within vmh control behaviors
- aggression-specific cells acquire increased responsiveness to social cues during transition from virginity to maternity vs responsivenes of mating-speicif cells remain unchanged
58
cells of testes
- sperm: modified gametes carrying haploid complement of dna
- steroli cells: nourish sperm during maturation- sour of adrogen binding protein, inhibin, activin, MIH
- leydig cells: source of androgen- intrestitial cells
59
male ejaculate
sperm- originates and mature in sminiferous tubules
- matures epididymis
cycle of sperm production 2 months
-200-500 million per ejaculation
- seminal fluid- produced by seminal vesicles, prostate gland, aqueous buffer vehicles for sperm transport- sugares, amino acids, vitamins, prostoglandins
- seminal plug: coagulation of semen at vaginal opening to prevent leakage
60
spermatogenesis
walls of seminiferous tubules consist of diploid spermatogonia, that are the precursors of sperm
61
spermatogenesis
in seminiferous tubules, stimulated by testosterone
-meiosis of each spermatocyte produces 4 spermatids
-Process takes over three weeks to complete
-Spermatids differentiate into sperm- spermatozoa
- over 100 million each day
-move to epididymis and portion of vas deferens where they are stored
62
steroidogenesis
production of testosterone occurs mainlyl in leydig cells under control of LH
-leydig cells= interstitial
-T aromatized to E2 in sertoli cells under control of FSH
63
gonaotropin action on testes
FSH-> sertoli cells-> ABP
LH-> leydig cells-> T
ABP and T go to germ cells lining testes to help w sperm maturation
64
mechanism of androgen action
steroid hormones cross membrane to intracellular receptor and act as transcription factor
65
sertoli cells
located in seminiferous tubule, make ABP
66
T action in male
- bone formation
-accessory sex glands
- skeletal muscle development
- vocal cords, skin
-testis
-external genitalia
-CNS
67
effects of androgen on males
-development of male structures
- maintenance of male structures
- sperm maturation
- neg feeback control of gonadotropins
- stimulation/maintenance of sex behavior
-stimulation/maintenance of aggression
68
T metabolism
- T reduced to 5 alpha-reductase and to dihydrotestosterone
- or aromatased to estradiol
- or converted to androstenidione and vice versa
69
sperm production pathway
seminiferous tubules to epididymus to vas deferens to urethra
70
ABP
androgren binding protein, carrier protein for testosterone, made by sertoli cells in seminiferous tubules
- stimulated by FSH
71
elephant seals
male rank matters
- dispute over territory, showing of aggression
72
male sex behavior
all behaviors necessary and sufficient to deliver sperm to egg
73
appetitive phase
all behaviors males use to gain access to female
74
consummatory phase
time when copulation occurs; corresponds to performance
75
sex drive
motivational force that brings individuals to seek sexual union, part of appetitive phase
76
courtship vs copulation
courtship: sex drive, libido, appetitive behavior
copulation: performance, potency, consummatory behavior
77
measures of motivation
columbia university obstruction test
- measuring time it takes for male to get to female
- bar pressing for acces to estrous female is measured
78
male rat copulatory behavior
-mount: pelvic contact
-intromission: penile insertion, vigorous dismount, genital autogrooming
- ejaculation: deep thrust, weak dismount, expulsion of semen, post ejaculatory interval
79
measures of male rat copulatory behavior
- ML= time from into to males first mount
- MF= # of mounts prior to ejaculation
- IMI= time between mounts
-IL= time from intro of female to male first intromission
- IF= # of intromissions prior to ejaculation
- III= time between I's
-EL= time from into to male ejaculation
- PEI= time between ejaculation and next mount
80
sex behavior in dogs
-anogenital investigation
- mount, ejaculation, dismount
-copulatory lock maintains sperm transport- only predators
81
sex behavior restoration
- testerone treatment maintains sex behavior after castration in dose-dependent manner
- castration reduces sexual responsiveness (motivation and performance)
- castrated males will not investigate females
- varies among species when behavior ceases after castration
82
hormone maintenance vs restoration
lower doses need to maintain vs restore behavior
83
hormone correlates of male sex behavior; replacement
-T
-Amdrostenedione
-dihydrotestosterone
-estradiol
T aromatase to E has central effects; behavior
T redustace to DHT has peripheral effects
84
estradiol and behavior
-castration + T,AE, or E = behavior
-aromatase inhibitor + T, AE, but no estradiol= no behavior
-T,AE+ E, ER Blocker= no behavior
- T effects of maintaining/restoring male sex behavior are due to conversion to E and subsequent E action
- DHT acts on periphery to regulate penile response
-T to Estradiol to brain
-T to DHT to penis
85
hormonal control of repro behavior in male rats
-T: mounts, intromission, ejaculations
- E: mounts, intromissions
- DHT: neither
- E + DHT: mounts, intromissions, ejaculations
86
neural control of sex behavior
-medial preoptic area
- olfactory bulbs
-bomeronasal organ
-amygdala
87
medial preoptic area
- mpoa-x eliminates male sex performance but not motivation
- electrical stim of mpoa accelerates ejaculation in male rats
- neurons release DA, important for male sex behavior
-ElaineHull: DA levels increase in males in presence of sexually receptive females, facilitates copulation
- critical for internal and external info: time of day, stimuli w estrous female, endocrine state of male, memoris of previous sex encounters
88
main and accessory olfactory bulbs
part of neural circuit involved in sex motivation among rodents
89
vomeronasal organ
detects info ant pheromones
- CNO-x eliminates some sex behaviors in some animals, not critical for sex repro in todents
- important for detection of non volatile components of chemosensory stimuli to prolong contact w partner
90
amygdala
receives projections from main and accessory olfactory bulbs w impnut from VNO- projects to MPOA via stria terminalis
- important for motivation; bar presses
- AMYG-x no bar press but will mate when in cage
- lesions of stria terminalis lead to reduced motivation
91
sex motivation vs performance
- male rats w medial preoptic lesions will bar press for acces to females but no copulation
- male rats w amygdala lesions will show reduced bar pressing for access to females, but will copulate`
92
neural circute underlying male sex behavior
mpoa-> PAG-> nucleus paragigantocellularis-> spinal cord motor neurons-> pudendal musculature
93
hormones and nervous system mediating sex behavior
- crystalline T to MPOA of castrated rats facilitates copulation
-effect reduced if aromatase inhibitors added
-e2 implants to MPOA + systemic DHT injection elicits full copulatory behavior- E2 mediates central mecks, DHT maintains peripheral sensitivity
-implants of T to MPOA increases dendritic spine density
Jennifer Swann- hamsters
-castration reduces dendritic spine density
- t restores density but not length
urine of estrous females- inc neural activity in MPOA, olf bulbs
-castration reduces neural responsiveness in MPOA but not olf bulb; reversed w T
94
individual differences of sex behavior
-sex behavior falls on continuum btwn hyposexual and hypersexual activity
- differences in performance due to differences in target tissues of hormones or other factors
- low T concentrations can restore matin behavior
-T needed for spermatogenesis, aggession, physical features that attract male
-APP, tau, synaptophysin in MOPA are elevated in continuously mating castrates
95
steroid independent male sex behavior
maters had higher levels of APP, tau, shyaptophysin in MPOA neurons vs non maters
- genetic mechanism for inheritance of steroid-independent male sex behavior
- castrated male beagles have feqet copulation but still ejaculate 3-5 years after castration
-sex experienced cats continue copulatin 3 yrs after castration vs others stopped copulation immediately after castration
-humans: no stereotypical behavior or position as in rodents
96
coolidge effect
enhanced mating performance of males with novel females
-male mammals will be less intimate w a specific partner if they have been with them for a long time
97
sexual orientation in rams
- 8% of rams prefer only males, ignore females
- male oriented males have smaller ovine sexually dimorphic nucleus than female oriented males
- persists in adults castrated and treated w t
-neitheroSDN nor partner preference influenced by T
98
developmental studies
- sex diff in oSDN volume appears in lamb fesutses on gestational day 135 before they are born
-critical period which T masculinizes oSDN occurs between GD 60 and 70, critical period for masculinization of genitalia from GD 30 to 60
-T affects differentiatio nof brain and genitals in diff time frames
- could explain how hormone variations during gestation may produce rams that preger to mate w other rams but possess masculine fenitals and other male typical neuroendocrine and behavioral traits
99
sex in garter snakes
-males emerge from winter hiernacula weeks before females, attempt to mate when females emerge
- many males attempt to mate w one female (mating ball)
-male has two hemi penises that insert into females two vaginae
-after first male intromits, female emits chemosensory signal to inhibit other males
100
garter snakes reproductive pattern
-dissociated reproductive pattern
- mating occurs when testes are regresesed- no circulating T
- indeminating sperm is from previous autumn
- after mating, testes grow to produce androgenss and sperm for nest spring
- mating NOT affected by castration, steroids, or gonadotrophins
- eliminated by MPOAX or pinealX bc two brain regions integrate nevironmental info that allows snakes to know seasonal info
101
factors that affect male sex behavior
- hormone leves: andorgen, estrogen
- hormones sensitivity: receptors, signal transduction
- neural systems
-experience
-environment: season, females, cognitive factors
102
parental behavior
any behavior that contributes directly to survival of fertilized eggs or offspring that have left the body of the female
103
paternal behavior
parental care by father
104
maternal behavior
parental care by mother
105
alloparental behavior
care provided by individuals that are not biological parents
e.g sibilings, aunt, unrelated older adult
- increasing survival, evolutionary
-look out for each other and predators
106
parental investment
extent to which parents compromise their ability to produce additional offspring in order to assist current offspring
- may result in conflict of interest btwn parents and offspring
- consider relative size and # of gametes
- alligators produce many offspring, elephants produce one
107
nature of parental care
-some species provide little to no parental care
- extent and nature of care depends on development of offspring
108
altricial
immature, helpless young
e.g rats, mice
109
precocial
well developed young, may be able to survive with little to no parental help
e.g guinea pig
110
semi precocial
young that need parental care, but who can thermoregulate, cling to parent
e.g humans
111
what is included in parental care
mammals
- nest building
-nursing
-pup retrieval
-play with older offspring
-provide food, shelter
birds
- nest building
-incubating eggs
-brooding newly hatched nestlings
- care for young until independence
112
parental behavior: birds
-nest parasites: female lays effs in anothers nest
- only female providing care more common than only male but still not that common
- male providing majority of care common in females that reproduce with multiple males
-biparental care
113
paternal care
- male builds nest, incubates eggs, cares for young
- females compete with each other to lay their effs in male nest
114
biparental care
- most common
- species are monogamous
-extent of care varies
- many develop brood pouch on breast: feathers lost, become highly vascularized during incubation to increase heat transfer
- sometimes both sexes dev brood pouch
115
crop milk
pigeon parents feed nestling crop milk during first 5 days
- produced by both parents
-ressembles small curd cottage cheese
- made in crop sac; exocrine gland and regurgitated to feed young
- gleams through skin on nestlings crop
- nestlings can double their weight w'in 34 hours of hatching
- inc # of seeds, insects after crop milk
116
hormones involved in avian parental behavior
-sex steroid hormones, gonadotropins association w courtship, egg laying- increase w onset of courtship, peak during egg laying, drop off during post hatchign care
- prolactin: induces formation of crop sac, brood pouch, stimulates parental behaviors
- shown to increase broodiness (incubation of eggs, clucking to keep track of chicks
117
ring necked doves
daniel lehrman
- behavior to hormone relationship
adult male
- T: courtship, proceptive behavior, nest building, copulation
-Prolactin: incubation, feeding squabs
adult female
- Estrogen: response to courtship, proceptive behaviot, copulation
- P: nest building, egg laying
-Prolactin: feeding squabs
118
parental behavior: mammals
- mammals nurse their young, maternal behaviors are primary
- maternal care includes providing shelter, warmth, cleanliness, protection, showing maternal aggression
- paternal behaviors
119
maternal behavior: marsupials
- marsupials have altricial young
- puch contains mammary glands, home for young
- time in pouch varies: consider effort to get food, avoid predators
- young leave pouch but return to mom to nurse
- short gestations, longer postpartum maternal care, but if young fall out/off mom does not retrieve them
120
maternal behavior: eutherian mammals
-have placentas during pregnancy
- live in more stable reliable habitates to have longer gestations and greater prenatal development
- 3 patterns: altricial, precocial, semi precocial
121
eutherian mammals: altricial young
- mother provides altriical young w food, shelter, care
-placentophagia= mom eats placenta, lots of nutrients, cleans up tracts to deter predators
- clean anogenital area to stimulate elimination of wastes, learn how to go to bathroom and keeps clean
- nurses young
huddles w pups for warmth
- often retrieves young that leave nest
122
eutherian mammals: precocial young
- capable of high defree ofindependence
- hider type animals: remain in hiding which mother forages for food, then comes back to nurse- deer
- eventually grow mature enough to follow mom
- follower type: animals have offspring that follow mom from birth- elephants, orcas, goats, giraffes
- mother nurses young and stays vigilant
123
eutherian mammals: semi precocial young
offspring are helpless but can cling to mother and move w her
e.g humans
124
paternal behavior evolutionarily
assumptions abt paternal behavior:
- increases male reproductive success
- female can not rear young alone
- cerainty of paternity is high
in reality not many species have paternal care
125
paternal behavior: cali mouse
- shows all parental behaviors except lactation
- parent forms long term pair bonds and remain togerther during breedin and non breeeding seasons
126
paternal behavior: common marmoset
-monogamous
-assist with birth
-chews food for babies
- carries young
127
testing mammalian parental behavior
- present rap pup to adults and observe how adult shows parental behavior
- nulliparous: never pregnant
- primiparious: pregnant for first time
-- multiparous: having multiple pregnancies
- during first day of exposure, males, non preg females ignore pups
- preg females soon show maternal behavior
128
parental care: sensitizaton= concaveation
occurs independent of hormones: effecs persists after removal of gonads, adrenals, pituitary
-behavior change induced by pups
- likely mediated by dopamine
- rapis onset IS hormonally mediated
- hormones assoc w pregnancy may act by reducing fear assoc w pups
129
motivation and maternal behavior
conditioned place preference tests: does rat prefer chamber exposed to pups or where given cocaine injection
- 8 days postpartum: pups
- 16 days postpartume: cocaine
- day 10: equal # of preference pups/coocaine
130
maternal behavior ciruitry
alison fleming
- MPOA is part of circuit mediating maternal behaviors and motivation to perform them
- role of experience
- human maternal care
- major contributor to the field
- c-FOS labling; seeing brain activity/neuronal activity- led to MPOA inclination
MPOA- copulatory behavior in males
131
MPOA pathway
- mpoa gets input from chemosensory pathway
- rats fear novel stimuli in environ; pups smell strange
-non moms avoid pups due to odors
- hormones may mediate maternal behavior by dec neg. assoc w pups and inc pos, so mom is drawn to pups
- lesions in any structure in pathway hasten maternal beh onset
- latency to maternal behavior is reduced after lesions to chemosensory organs, amygdala
-lesions of med amyg accelerate concaveation in nulliparous subjects
- critical for expression of maternal behavior
- both olfactory and vomeronasal inputs to MPOA inhibit mat beh
- amygdala inhibits rat mat behav
-mat beh occurs when MPOA is released from inhibition by hormones associated w late pregnancy
- dec repulsiveness of pup oder by: exposure to maternal hormones, repeated exposure to pups, making adult anosmic
-amygdala; motivational aspects
- lesions; eliminate neg stuff
132
experience and maternal behavior
- experienced moms are better moms
- mothers w previous litters give maternal care to foster pus much earlier vs primparous moms
- hormones are impt for primin first time moms to behave maternally but experience mediates behavior for future offspring
133
offspring behavior and maintenance of maternal behavior
judith stern
- established importance of somatosensory (tactile) feedback from pups to maintain maternal care
-functional neuroanatomical model of ammalian maternal behaviors
134
endocrine correlates of mammalian parental behavior
Jay Rosenblatt- pioneer in study of hormones and maternal behavior
-PRL, placental lactogen, estrogens, ocytocin, B-endorphin, CCK, prostoglandins, relaxin
- blood-borne factor induces maternal behavior
-parabiotic transfer of blood from new mom to nulliparous female results in maternal behavior by nulliparous female w'in 24 hrs
135
hormones associated w maternal behavior in rabbits: nest building
- rabbit lines nest w her hair, falls out toward pregnance
- PRL dependent: if trt w/DA block PRL release, dec nes bldg, concurrent treatment with PRL reverses blocking effect
- inc PRL assoc w/ inc E to P ratio towards end of pregnancy
- estrogen progesterone ratio primes system
- P high during pregrnancy- maintains uterine lining and drops back off after baby born
- increase estrogen to decrease progesterone to prime system for PRL release
- estrogen goes up w prolactin
- prolactin has no effect without priming effect
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blood borne factors in maternal behavior
- prolactin: brain needs to be primed w estrogen and progesterone for prolactin to induce maternal behavior
- prolactin reduces latency to maternal behavior
- prolactin plays role in maternal behaviors in rats and nest building in rabbits
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estradiol and maternal behavior
- also blood borne factor
-estradiol stimulates maternal behaviors via ERs in mpoa
- E:P ratio changes thru out pregnancy
- implants of E2 into MPOA trigger maternal behavior
- # of ERs in MPOA inc during preg
- a protein product prod by ER stim is oxytocin R
- estrogen leads to protein product oxytocin Rs
estrogen acts as transcription factor
- increase transcription of receptors
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maternal behavior in sheep
seasonal breeders, lambs born in spring
- moms learn to discriminate own lamb based on olfactory cues emitted from lamb
- exclusive social bond formed within firs hour of lambs life
- rewuires inc ratio of E:P, characteristic of parturition
- also requires vaginocervical stimulation which evokes release of oxytovin
- oxytocin inj to CSF of non pregnant ewes induces full complement of maternal behavs
- oxy imp for maternal acceptance of alamb and maternally motivated behaviors
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oxytocin and maternal behavior
- also blood borne factor
- oxytocin R binding in mpoa is greater in lactating females that exhibit high rates of licking and grooming vs lactatingfemales w lower rates of these behavs
- imp for mat beh in sheep
- I.C.V inj of oxytocin to E2 primed OVX rats induces maternal beh within the hour
- oxytocin release during vaginal delivery may be impt for robust maternal beh
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hormonal correlates of paternal behavior: cali mouse
- fathers have PRL levels comparable to moms
- T is necessary for paternal behavior
- T working via E2 is necessary for paternal behavior
- MPOAs have higher levels of aromatase vs non fathers
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hormonal correlates of paternal behavior: common marmoset
- prolactin levels increase when infants are in cage w fathers
- fathers showing paternal behavior hav e5X inc PRL and recutions in T compared to non fathers
- T levels dec when exposed to infant odors, sugg odor is impt signal for offspring recognition
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hormonal correlates of paternal behavior: humans
- expectant human fathers show reduced T, inc E2
- ooxytocin levels also positively correlated w paternal behaviors
- hormonal basis of human maternal behavior is unclear due to definition of maternal behavior
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why does mom stop showing maternal behavior
- as pups mature, mom rats spend less time w pups during each nursing bout
- thermoregulation may be mechanism
-PRL stims secretion of corticosterone which increases metabolic rate and raises moms body temp
- larger pups prod more heat which dec moms ability to dissipate heat
- mom has to avoid overheating so leaves litter; duration of nursing bouts dec
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how do pups find their way back to nest
- attraction to odor of lactatin moms
- caeocotrophs: small pellets of parially digested food matter; source of moms odor
- attractiveness of caecorophs to pups increases as pups age
- pups lose interest in caeotrophs day 28 when moms decproduction and pups weaned
