Oxytocin and Social Behaviour

Question 1

oxytocin (what is it, what does it play a role in?)

Answer 1

• Neuropeptide (protein in nature)
• Produced in hypothalamus and released by the pituitary gland
• Binding to receptors it: acts as a NT in the brain and acts as a hormone in the body
• Underlies parturition, lactation, social behaviour, and bonding/attachment (both parental and partner/romantic), feeding behaviour, stress, fear, and anxiety

Question 2

evolution of oxytocin

Answer 2

• Oxytocin homologs (sharing the same evolutionary history – ex. vasopressin), originated 700 million years ago
• Found in diverse array of vertebrates
• The role of oxytocin is relatively conserved and related to ancient functions

Question 3

social behaviour

Answer 3

• any action directed by an individual towards another individual
• Ex. Mating, parental care, communication, social recognition, allogrooming (social grooming – grooming another individual), social play, social learning and memory, fighting, altruism

Question 4

play

Answer 4

motor activity performed postnatally that may appear to have no purpose, but does

Question 5

3 types of play

Answer 5

• Object: pushing, throwing, tearing, or manipulating inanimate objects
• Locomotor: leaping, jumping, twisting, shaking, whirling, somersaulting, rolling, or chasing their tail
• Social: activity directed toward another living being (always involves 2+ animals; important to consider both)

Question 6

distinguishing play behaviours

Answer 6

• can distinguish play behaviours from hunting, mating, or aggression by:
• Order and frequency of behaviours
• Play markers (signals that initiate, continue, and warn of play)
• Vocalization
• Facial expression
• Role reversal and self-handicapping (dominant animals will reverse roles and will inhibit abilities while playing with subordinate animals – ie. Won’t bite as hard as it can)

Question 7

development of play behaviours (age and time)

Answer 7

• Age dependent:
  characteristics of early life stages in most species
  – Continues into adulthood in some species (ex. Rodents, canids, primates)
• Time dependent:
  Starts after individuals have associated with each other for a certain amount of time

Question 8

functions of play behaviours (short and long term)

Answer 8

• Short-term:
• • Reduces tension
• • Self-assurement
• • Enjoyment or reward
• Long-term:
• • Long-lasting social bonds
• • Social and emotional flexibility
• • Improves physical, cognitive, and conflict resolution skills
• • Reactions to unexpected situations

Question 9

social play behaviour in rats

Answer 9

• Initiation/Pouncing: making contact with partner (ie. jumping, nuzzling)
• Evasion: recipient animal avoids contact/runs away
• Partial rotation: upon contact, recipient begins to rotate but stays standing
• Full Rotation: upon contact, recipient fully rotates, going into supine with initiator standing over it
• Boxing/Wrestling: both upright, pushing/grabbing each other
• Following/Chasing (self-explanatory)
• Sniff/Grooming (self-explanatory)

Question 10

social play behaviour: player vs. playee

Answer 10

• The player: intiates and follow/chase (ex. Blue rat)
• The playee: evades and rotates (ex. White rat)
• Can flip back and forth between these roles, but dominant is usually player and playee is usually subordinate

Question 11

rat group social play following prenatal alcohol exposure experiment

Answer 11

• control: pellet diet; PAE: alcohol diet
• Observe play behaviour in triads with 2 controls and 1 PAE and 2 PAES and 1 control -> control choose to initiate more with control animals than PAE animal, and are more likely to reciprocate play with control vs. PAE
• • Likely that PAE animal does something that controls don’t like, inhibiting social play
• • PAE will play/reciprocate with both controls and PAEs an equal amount

Question 12

oxytocin and play behaviour in mice experiment

Answer 12

• Injection of either oxytocin or saline before testing
• Social interaction test (pair of unfamiliar stranger mouse and experimental mouse)
• Recorded time spent in social interaction -> Includes active content (ex. Sniffing, follow/chase, grooming, playing)
• Results: oxytocin increases social interaction time in males and females

Question 13

oxytocin and play in dogs

Answer 13

• Nasal spray of oxytocin or saline (all subjects received both conditions)
• In familiar room with familiar dog partner
• Recorded behaviours for 60 minutes
• Recorded as play sessions, starting with play signal/initiation, including play behaviours, and ending when dogs moved 1m+ away (play over)
• results: oxytocin increases number of play signals given and duration of play in dogs

Question 14

anxiety

Answer 14

• psychological, physiological, and behavioural state induced in animals and humans by a threat to well-being or survival, either actual or potential
• In contrast, fear is a response to an immediate and real danger
• When these ADAPTIVE functions are prolonged and begin to interfere with the
  ability to cope they can become PATHOLOGICAL

Question 15

cross-species responses to anxiety

Answer 15

• Physiological: increased arousal, autonomic and neuroendocrine activation (ex. HPA axis)
• Behavioural: decreased exploration, feeding, and sexual behaviours, and increased escape/flight and defensive/fight behaviours

Question 16

modeling anxiety-like behaviour in rodents

Answer 16

• Physiological = HPA axis activation
• Behavioural = trait anxiety and behavioural inhibition
  Ex. Agoraphobia

Question 17

modeling agoraphobia in mice

Answer 17

• Elevated plus maze: lower times on open arms indicates increased anxiety
• Open field: lower times in center indicates higher anxiety
• Light-dark emergence: lower times in light indicate higher anxiety
• Novelty suppressed feeding: higher latency (the longer it takes you eat) indicates higher anxiety

Question 18

confounds to agoraphobia measures (and how to control for them)

Answer 18

• Elevated plus maze: less anxiety or less inhibitory control
• Open field and light-dark: less anxiety or more locomotor activity
• Novelty suppressed feeding: less anxiety or more hungry
• All tasks: more anxiety or more fear/stress-coping behaviour
• Controlling for these confounds: measure locomotor activity, measure appetite, measure inhibitory control
• Controlling for fear confound: battery of tasks (measuring them on multple measures), tests/tasks over time (longitudinal response), directly test fear response

Question 19

things that reliably show less anxiety in mice

Answer 19

• Anxiogenic drugs
• Chronic stress paradigms
• Genetically modified “high anxiety” mouse strains

Question 20

oxytocin and anxiety behaviour in rats

Answer 20

• Female rats given central pump of oxytocin or saline for 5 days, then put in elevated plus maze
• Measured open arm entries, time in open arm, total arm entries, and percent in open arm
• Result: oxytocin decreases anxiety-like behaviour and stress response in female rats

Question 21

oxytocin and social anxiety disorder in human males

Answer 21

• males with SAD and without (controls) given nasal oxytocin spray or placebo spray before fmri scan
• Fmri scan done during emotional face matching task -> oxytocin does not affect matching
• Looked at BOLD (blood oxygen level dependent) signal in the amygdala during the task
• RESULT: oxytocin decreased amygdala reactivity in fearful faces of males with SAD