18: Drugs & Social Behaviour

Question 1

Vasopressin and oxytocin are a duplication of what?

Answer 1

Ancestral gene after radiation from cyclostomes.

Question 2

In the past, vasopressin was connected to _____ and oxytocin to _____.

Answer 2

Osmoregulation and reproductive physiology.

Question 3

What are vasopressin’s primary functions and how are they maintained? What is a recent finding?

Answer 3

Antidiuretic, retains water and constricts blood vessels. Maintained by vasopressin released from posterior pituitary.

Receptors in brain help regulate reproduction and social behaviour.

Question 4

In the treatment of cardiac arrest, what can vasopressin substitute for?

Answer 4

Epinephrine.

Question 5

How does oxytocin differ from vasopressin and what are its functions?

Answer 5

Differs by 2 amino acids from vasopressin.

Functions are connected to physiology of birth and lactation. Connected to central control of social and sexual behaviours, and anxiety.

Question 6

List the vasopressin and oxytocin receptors.

Answer 6

Vasopressin:

• AVP₁ₐ: brain & periphery
• AVP₁b: brain & periphery
• AVP₂: kidneys
• VACM: heart, vascular endothelium, renal collecting tubules

Oxytocin:
- OXTR: brain & periphery

Question 7

What occurred during vasopressin and oxytocin experiments regarding monkey behaviours? How can they be interpreted?

Answer 7

Oxytocin increased staring of subordinate monkey at dominant; vasopressin similar effect, but more potent. Resulted in reciprocal changes in untreated partners, softening behaviours.

Prosocial effects can be interpreted as improvement in efficiency of bidirectional social communication.

Question 8

Injection of vasopressin _____ and AVPR₁ₐ antagonists ____ what?

Answer 8

Increase; decrease. Social recognition.

Question 9

In rat studies, what prolongs and what diminishes individual social memory?

Answer 9

ICV administration prolongs; AVPR₁ₐ antagonist diminishes.

Question 10

AVPR₁ₐ-KO mice lack what?

Answer 10

Formation of individual social memory.

Question 11

Brattleboro rats unable to synthesize _____ result in what?

Answer 11

AVP. Results in deficit of social memory formation.

Question 12

What do vole studies suggest with regards to vasopressin being considered a pair-bonding hormone? Which hormone is predominant in either sex?

Answer 12

Extra AVP₁ receptor via adeno-associated viral vector induces monogamous behaviour.

Vasopressin signaling predominant in males; oxytocin signaling predominant in females.

Question 13

List two findings of vasopressin influencing human bonding.

Answer 13

Allele 334 of AVPR₁ₐ gene associated with marital problems and lower quality of marital relationship, but only in males.

Long isoform of AVPR₁ₐ gene associated with generosity and possibly reduced selfishness.

Question 14

Polymorphism of OXTR gene may be associated with behavioural differences. What findings support this?

Answer 14

Carriers of the A allele have increased sensitivity to stress, reduced social skills, and more negative mental health outcomes relative to those who carry 2 copies of the G allele.

Question 15

MDMA significantly increases plasma oxytocin concentrations. Genetic variants of the OXTR gene show differences in the emotional and social effects of MDMA. What findings support this?

Answer 15

Trust and pro-social behaviours are enhanced in TT carriers compared to those who carry a single or double G allele.

Question 16

Intranasal oxytocin administration in a facial recognition study resulted in what? Were there any sex differences?

Answer 16

Identity recognition improved, but only for faces with neutral or angry expressions. There were no sex differences.

Question 17

What did a study examining the effects of oxytocin by nasal injection show in males involved in a monogamous relationship? With single males? What do these findings suggest?

Answer 17

Males in a monogamous relationship increased the distance between them and an attractive female by ~15cm. This effect was not observed in single males.

Suggests oxytocin may help to promote faithfulness in monogamous relationships.

Question 18

What were the findings of a study where subjects with Autism Spectrum Disorder received intranasal oxytocin in the morning and afternoon for 6 weeks? What are the drawbacks?

Answer 18

Improvement in measures of social cognition and quality of life.

Number of oxytocin-like drugs, especially non-peptidergic ones, is scarce.

Question 19

What did fMRIs demonstrate when 23 healthy nulliparous women were shown infant faces? What were the findings for the portion receiving intranasal oxytocin?

Answer 19

Control: increased activity in VTA, putamen, amygdala, and insula.

Oxytocin: significantly decreased effect in same structures.

Question 20

Social factors influence drug abuse. Conversely, drugs of abuse alter social behaviour. With this in mind, what is a problem with studying drug abuse?

Answer 20

Drug taking often associated with social environment, whereas testing of drug usually performed on subjects in isolation.

Question 21

What is the effect of alcohol and stimulant drugs on social behaviour? How do social contexts influence these drugs?

Answer 21

Improve attractiveness of social stimuli and the desire to socialize.

Social contexts increase alcohol and stimulant effects.

Question 22

What is the effect of opioids on social behaviour? How do social contexts influence them?

Answer 22

Improve feelings of social connection. Taking is less influenced by the presence of others.

Question 23

What is the effect of cannabis on social behaviour? How do social contexts influence it?

Answer 23

Reduce social interactions. Taking is less influenced by the presence of others.

Question 24

THC _____ social play behaviour in rats. Why?

Answer 24

Reduces. Through stimulation of CB₁ cannabinoid receptors.

Question 25

Inadequate _____ increases vulnerability to drug abuse later in life, whereas _____ is protective.

Answer 25

Neonatal care; attentive care.