social behaviors

Question 1

affiliation

Answer 1

social behaviors that bring animals together
-thought to have evolved from reproductive and parental behaviors: short term associations that have evolved to form long-term bonds

Question 2

monogamy

Answer 2

single mate (pros: advantageous when both sexes provide parental care, certainty of paternity; cons: maybe your mate doesn’t have great reproductive fitness, could jeopardize your own reproductive fitness)

Question 3

polygamy

Answer 3

multiple mating pairs (pros: mate selection; cons: less paternal certainty, less paternal investment, competition)

Question 4

polygyny

Answer 4

multiple females, one male: pros: mating with a “fit” male, less paternal investment, maybe other females can help with rearing of offspring, less competition)

Question 5

polyandry

Answer 5

multiple males, one female

Question 6

pros of social groups

Answer 6

prey detection, defense, dilution, increasing foraging efficacy, group defense/pooling of resources, increased mating opportunities

Question 7

cons of social groups

Answer 7

ease of disease transmission, predator detection, increased competition for resources

Question 8

polygamous vs. monogamous species: testosterone levels

Answer 8

polygamous species: higher levels of testosterone, larger testes, higher sperm numbers

Question 9

pattern of oxytocin binding in MALES: prairie voles vs. montane voles

Answer 9

prairie voles: higher oxytocin binding sites in the nucleus accumbens, fronto-parietal cortex, lateral amygdala, thalamus

montane voles: higher oxytocin binding sites in lateral septum

conclusion: prairie voles and montane voles differ in mating styles (monogamous vs. polygamous) and have different oxytocin binding sites in different brain regions

Question 10

receptor distribution of oxytocin: prairie vole females vs. montane vole females

Answer 10

• prairie vole females have greater oxytocin receptors in nucleus accumbens and prefrontal cortex
• injection of an oxytocin receptor antagonist in prairie vole females–> decrease in partner preference BUT only when injected into the nucleus accumbens and prefrontal cortex

Question 11

behavioral effects of oxytocin

Answer 11

FEMALE pair bonding
promotion of maternal behaviors 
sex behavior 
non-mating affiliation 
social memory 
decreased anxiety

Question 12

vasopressin: prairie voles vs. montane voles MALE

Answer 12

male prairie voles have a higher density of vaspressin 1 receptors in the ventral palladium compared to montane male voles (MV voles have more vasopressin receptors in the lateral septum)

• injection of vasopressin agonist in montane voles did NOT induce monogamous behavior
• injection of vasopressin ANTAGONIST led to a decrease in partner preference in prairie voles

Question 13

induction of monogamy with viral vectors: overexpression of V1 receptors in montane voles

Answer 13

viral vector infusion into the ventral palladium of male montane voles saw a HUGE increase in vasopressin receptor expression, as well as a significant increase in affiliative behaviors (i.e. huddling)

Question 14

circuit: nucleus accumbens, prefrontal cortex, ventral pallidum

Answer 14

part of a pair bond neural circuity; these 3 regions are all associated with the reward pathway and suggest that pair bonding is rewarding to prairie voles

Question 15

dopamine and pair bonding

Answer 15

dopamine agonists: increase pair bonding in females
dopamine antagonists: decrease in pair bonding, even in montane voles who had been treated with viral vector that led to the overexpression of v1 receptors
dopamine increases during mating

Question 16

opioids and social contact

Answer 16

• endogenous opioids increase after social contact
• contact comfort in chicks: when being held, chicks will demonstrate contact comfort by shutting their eyes
• can reduce contact comfort in chicks through administration of a opioid antagonist–> represented by a decrease in the effectiveness in contact comfort in causing chicks to shut eyes

with rats, opioid antagonists decrease the effectiveness of contact comfort in decreasing distress vocalizations