Lecture 8

Question 1

Define social behaviors

Answer 1

interactions between individuals in which one or more of the individuals benefit

Question 2

describe two social behaviors

Answer 2

Affiliation; social behaviors which bring individuals closer
e.g. courtship and parental behaviors and Aggression or Territorial behavior: social behaviors which keep animals apart

Question 3

what are the costs of living in groups

Answer 3

Costs
Increased ease of disease transmission
Increased competition for resources
Increase conspicuousness to predators

Question 4

what are the benefits of living in groups

Answer 4

Benefits
Anti-predator detection, defense and dilution
Elevated foraging efficiency
Group defense of resources
Increased mating opportunities

Question 5

how do social behavior change during the year in voles

Answer 5

During breeding season, female territories do not overlap

After breeding season, female territories do overlap and meadow voles live socially

Question 6

describe the mating patterns and the habitat of the three voles

Answer 6

Prairie Voles
Grasslands in mid-western USA
Monogamous
Biparental
Meadow Voles
Grasslands in eastern USA
Highly polygamous
Montane Voles
Grasslands in western USA
polygamous

Question 7

describe how different hormones play the same role in the two sexes between voles during pair bonding

Answer 7

Female prairie voles develop partner preference following oxytocin infusion and Establishment of partner preference in male prairie voles is dependent on vasopressin

Question 8

in zebra finches what role does the oxytocin antagonist play

Answer 8

Oxytocin antagonist (OTA) reduces the time spent with same sex cage mates

Question 9

partner preference is facilitated and blocked by what

Answer 9

Dopamine agonist in NAc -> facilitated partner preference

Dopamine antagonist in NAc -> blocked partner preference

Question 10

how does highly affiliative species tend to differ from solitary species

Answer 10

Highly affiliative species tend to have a different pattern of OXT and AVP V1a receptors than solitary species

Question 11

what happens when you seperate pup voles from their families and what does this suggest

Answer 11

Prairie voles emit ultrasonic distress vocalization and increased levels of corticosterone while montane voles do not. this suggest that corticosterone and/or stress response may be an important mediator of partner preference

Question 12

describe the different Corticosterone effects on partner preference in prairie voles according to sex

Answer 12

corticosterone and stress increased partner preference in male voles and did the opposite to females. adrenalectomy increases partner preference in females and did the opposite in males.

Question 13

describe the similar Corticosterone effects on partner preference in prairie voles according to sex

Answer 13

gonadal steroid hormones showed no change in both sexes in partner preference

Question 14

how does Testosterone affect Affiliative Behaviors

Answer 14

Males of polygamous species have higher testosterone levels

Question 15

explain how testoterone has limitations in affiliative behaviors

Answer 15

Testosterone has no effect on polygamous or monogamous behavior on different voles

Question 16

what are the Two Models of Agonistic Behavior

Answer 16

1. Aggression and submission may represent opposite ends of a single behavior continuum
2. Aggression and submission may represent different aspects of an individuals behavior

Question 17

describe 4 pieces of evidence that show that androgens mediate aggressive behavior

Answer 17

1. Seasonal variation in circulating testosterone coincides with seasonal variations in aggression
2. Aggressive behaviors increase at puberty
3. Males are generally more aggressive than females
4. Castration typically reduces male aggression, testosterone replacement restores aggression

Question 18

In many species, non-breeding season behavior is regulated by what and how?

Answer 18

estrogen. it inhibits aggression in long days and enhance aggression in short days.

Question 19

if testosterone is removed by castration how does this affect aggression

Answer 19

it will block summer aggression

Question 20

what blocks winter aggression

Answer 20

Anti-androgen or aromatase inhibitor

Question 21

in Harris’s Sparrows how is social rank indicated and what does this correlate with

Answer 21

it is indicated by plumage color and it positively correlates with testosterone levels

Question 22

describe how puberty affects aggression

Answer 22

During puberty the testis grow larger and the Leydig cells secrete increasing amounts of androgens into the circulation.
The resultant increase in circulating levels of androgens is associated with increased display of aggression

Question 23

describe the behavior between male syrian hamsters pre, mid and post puberty.

Answer 23

Pre-pubescent males attack the face and cheeks of their opponent.
mid-puberty, males undergo a transition where attacks are aimed at the flanks
post puberty males attacks to the belly and rump.

Question 24

what happens to the attach frequency and the contact time between hamsters as the pass through puberty

Answer 24

they both decline

Question 25

describe the Adaptive Advantage of Pubertal Aggression

Answer 25

rodents such as hamsters and voles, disperse during puberty and are exposed new threats
(predators and other male’s territories) dispersing males have evolved to be aggressive which may increase their chances of survival and reproductive success

Question 26

how is puberty different in primates than it is in hamsters

Answer 26

pubertal increase in testosterone is not always associated with increased displays of aggression.

Question 27

in primates males who are victim to increased aggression and have to disperse, what are two strategies

Answer 27

Burst into a new troop and attempt to seize membership status (Usually met by strong resistance/aggression from resident males) or they live along the periphery of a new troop and slowly “sneak” in (Risks of starvation and predators)

Question 28

name 3 characteristics that Male offsprings of high ranking females have

Answer 28

1. Low levels of cortisol
2. Risk taking personalities
3. More likely to attempt to claim membership status in a new troop

Question 29

name 3 Hypotheses for sex differences in aggression

Answer 29

1. Higher androgens
2. Brain are exposed to androgens during development and thus are “hardwired” (organized) differently
3. Learn different culturally accepted gender roles

Question 30

describe how Androgens organize AND activate aggression in mice

Answer 30

Male mice castrated before P6, T in adulthood ->low aggression
Female mice ovariectomized before P6, T in adulthood -> low aggression
Male or female prenatally gonadectomized, T prior to P6, T in adulthood -> typical male aggression

Question 31

What are the three groups of nonapeptides and what are the corresponding species

Answer 31

Bony fish -> isotocin (IT) arginine vasotocin (VT)
Lungfish, amphibians, reptiles, bird -> mesotocin (MT) arginine vasotocin (VS)
Eutherian mammals -> oxytocin (OT) arginine vasopressin (VP)

Question 32

Brain overlapping regions and OXT/ AVP?

Answer 32

Overlap between regions with high OXT and AVP receptors in prairie voles and reward system in the NAc, PFC, VP

Question 33

Difference in brain circuitry of Prairie and Montane vole.

Answer 33

Prairie Vole; Highest oxytocin receptor density found in prelimbic cortex, BNST, nucleus accumbens, lateral amygdala
Montane Vole; Very different pattern of binding

Question 34

Dopamine effect in the Nucleus Accumbens

Answer 34

Dopamine agonist in NAc facilitated partner preference.

Dopamine antagonist in NAc blocked partner preference

Question 35

Describe the mating and reward system

Answer 35

Dopamine released into NAc in response to mating. The coordination of OXT, AVP, DA facilitates pair bond.