hormones and behaviour

Question 1

how can hormones influence behaviour

Answer 1

• biological rhythms
• eating and drinking
• reproductive behaviour
• social behavior
• stress

Question 2

how does the pineal gland act in mammals?

Answer 2

via the cervical ganglia

Question 3

what does melatonin control

Answer 3

• the timjing of onset of sleep

- breeding conidition in seasonally breeding animals

Question 4

What does Atrophy mean

Answer 4

shrivel up

Question 5

how does breeding in hamsters work

Answer 5

1. senses longer autumn nights
2. pineal gland prolongs nocturnal secretion of melatonin
3. hypohtalamus becomes sesnitive to negative feedback effects of gonadal steroids
4. less GnRH released
5. less gonadotopin released, so gonads atrophy

Question 6

what is Ghrelin

Answer 6

• Peptide hormone
• 28-amino-acid peptide secreted by cells in stomach epithelium
• stimulates feeding
• stimulates release of growth hormone (GH) from pituitary
• ghrelin-secreting neurons in brain also involved in control of feeding

Question 7

how does ghrelin levels change

Answer 7

• rise prior to mealtimes and at night

* drop following a meal

Question 8

what is odd about obese peoples ghrelin levels

Answer 8

• have lower ghrelin before eating
• but following a meal their levels do not drop
→ a ghrelin system unresponsive to feeding and therefore always hungry?

Question 9

What does Pro-oestrus mean

Answer 9

follicular development and ovulation

Question 10

what does oestrus mean

Answer 10

receptive period during which fertilisation is most likely to lead to pregnancy

Question 11

what did Beall & Tracy (2013) find?

Answer 11

• N = 124 normally ovulating women, aged 17–47 (undergrad + community samples)
• asked on-line what colour shirt they were wearing
• classified as high fertility or low fertility based on reported time since last period

wore red or pink more when ovulating

Question 12

what did miller et al (2007) find?

Answer 12

• recorded tip earnings by dancers in lap-dancing club

* dancers provided information on their menstrual cycle and use of hormonal contraception

Question 13

What is oxytocin

Answer 13

• a mammalian peptide hormone that acts on the central nervous system
• generally associated with uterine muscle contraction at birth and milk letdown
• also governs a suite of prosocial behaviours as do analogues (e.g. isotocin) in other taxonomic groups

Question 14

How does oxytocin work with parental care

Answer 14

• female rats bred for high levels of maternal behaviours have more oxytocin receptors in the central nucleus of their amygdala
• female prairie voles that show more maternal behaviour have higher oxytocin receptor density in their nuclear accumbens
• blocking these receptors inhibits maternal behaviour

Question 15

how does oxytocin work with alloparental care

Answer 15

• neonate (just born) female prairie voles injected with oxytocin are less likely to attack novel stimulus pups
• neonate male prairie voles injected with an oxytocin antagonist show reduced alloparental care

Question 16

What did Madden & Clutton-Brock (2010) find

Answer 16

• N = 36 meerkats (28 males, 8 females) injected with oxytocin vs saline control
• treatments reversed 3–5 days later
• recorded suite of prosocial behaviours

Question 17

what did Kosfeld et al (2005) find about trust?

Answer 17

• 2-player economic ‘trust’ game
• investor and trustee each receive 12 monetary units
• investor chooses to send 0, 4, 8 or 12 MU to trustee
• amount sent is tripled by experimenter
• trustee chooses how much of total to send back
• N = 194 healthy male participants
• 3 puffs per nostril of oxytocin vs control (double-blind) 50 mins before playing game

Those who received oxytocin made transfers ~17% higher than control group

Question 18

What did Zak et al (2007) find about genorosity?

Answer 18

• N = 68 men
• ‘one-shot’ economic game involving a voluntary donation
• given oxytocin vs control via nasal spray
• donations were ~80% higher in oxytocin group

Question 19

What did Marsh et al (2010) find about social sensitivity

Answer 19

• used well-validated set of photos of facial expression
• blended with neutral expression to create varying emotional intensity
• participants classified expression 35 mins after oxytocin vs control nasal spray

→ oxytocin increases sensitivity to positive emotional expression

Only the happiness condition had a significant difference. Oxytocin has a positive affect on positive emotions. It increases peoples ability to identify happy faces.

Question 20

Facts about orgasm

Answer 20

• plasma oxytocin increases during orgasm—in males and females
• plasma oxytocin levels increase during self-stimulated orgasm
• oxytocin evokes feelings of contentment, reductions in anxiety and feelings of calmness and security around mate (trust and generosity?)
• may indicate that sex promotes pair bonding

Question 21

What does the endocrine ssytem and nervous system have in common?

Answer 21

• communication and control systems
• take inputs and effect outputs
• be influenced by prior exposure