Brain Peptides and Social Behaviors

Question 1

where is all oxytocin made?

Answer 1

paraventricular nucleus (PVN) (Magnocellular layer)

Question 2

what is an example of feedback involving oxytocin? (from previous slide too)

Answer 2

uterus contractions send signals to hypothalamus which releases more oxytocin

Question 3

what is the function of oxytocin in the VMN?

Answer 3

stimulates lordosis in female rats

Question 4

what is the function of oxytocin in female rats?

Answer 4

1. maternal behavior
   ICV infusion of OT in ovariectomized, estrogen/progesterone primed virgin rats initiated full maternal behaavior within 1 hr;
   antagonist delay onset but does not affect maintenance of maternal behavior;
   lesioning the PVN does not disrupt maternal behavior once established
2. social behavior

Question 5

describe maternal behavior in sheep

Answer 5

Ewes learn odor of lamb within minutes of delivery;
vaginal cervical stimulation initiates maternal behavior;
two distinct process: initiation of maternal responsiveness and olfactory learning of lamb odors

Question 6

describe what happens to oxytocin KO rat babies?

Answer 6

1. they are not distressed by being in isolation from mother - fewer calls than WT
2. they don’t try as hard to be with their mom

Question 7

describe the importance of oxytocin in social cases with an experiment

Answer 7

1. SOCIAL: selective social amnesia - WT mice recognize other rats based on smell, so their smell time decreases when the same mice is introduced. OTKO mice do not habituate, so if the same mice is brought to them, they treat it as a different mouse each time
2. NON-SOCIAL: both WT and OTKO mice habituate to non-social stimuli

Question 8

describe the difference between social and non-social cues in rats recognizing individuals

Answer 8

1. if rat that is being introduced is scented with a non-social cue, both WT and OTKO will habituate
2. if rat that is being introduced is scented with a different cue, WT will still recognize it as the same mice, but OTKO will recognize it as a different one because it uses the non-social scent

Question 9

specifically which area of the brain does oxytocin act on to get social behavior?

Answer 9

1. oxytocin acts on amygdala
2. injection of OT into amygdala rescues social recognition in OTKO mice
3. OT antagonist injected into amygdala but not olfactory bulb blocks social recognition in WT mice

slide 24 - 31

Question 10

what is experiment that shows that OT stimulates pair bonding in females?

Answer 10

Partner Preference Test

1. COHABITATION, NO MATING with partner: females given CSF spend half time with stranger, half time with partner. females given OT spend more time with partner
2. WITH MATING with partner: CSF injection > spend more time with partner. OT antagonist injection > spend as much time with partner as with stranger

Question 11

How to control for diffusion in oxytocin injection studies? (not covered in lecture)

Answer 11

Inject OT into control site. Staining should be the same in both sets of animals

Question 12

What is the social effect of oxytocin on people?

Answer 12

1. Increases trust
2. Increases gaze to eye regions
3. face recognition
4. Increases emotional empathy
5. salience of social stimuli
6. increases saliency of social stimuli

Question 13

is oxytocin critical for learning or recall?

Answer 13

1. learning (memory formation)
2. give OT to one group 5 mins before introducing a rat and to another group, give OT 30 min after introducing to a rat
3. when OT is given before, they remember (spend less time sniffing)

Question 14

the feature of extra hypothalamic vasopressin pathway?

Answer 14

sexually dimorphic

Question 15

vasopressin and male social behavior

Answer 15

1. male sexual behavior
2. territorial behavior
3. aggression
4. vocal communication

Question 16

Chemistry of Pair Bonding

Answer 16

1. OT and AVP: perception of social stimuli, mutant mice have social amnesia
2. dopamine: reinforcement learning
3. opiates: hedonics

Question 17

neural model for pair bonding formation

Answer 17

individual specific: input from PFC to NAcc to VP

Question 18

genetics of human relationship

Answer 18

genetic polymorphism

1. receptor in vasopressin in male change male’s behavior
2. receptor of oxytocin in female do the same