Social bonding and stress Flashcards
Define the pituitary gland.
A pea-sized endocrine gland at the base of the brain involved in growth and development, as well as controlling other endocrine glands.
Which brain area controls the pituitary gland?
The hypothalamus.
What are the major functions of the hypothalamus? List 3.
- Maintains homeostasis
- Involved in sleep
- Involved in emotional control
In nervous stimulation of endocrine systems, what is characteristic about the nerve terminals?
They do not end on another neuron at a synapse, but innervate blood vessels instead.
Animals often bond for life. This is a survival strategy. Give 2 reasons why.
- Social support promotes adaptation
2. Social support aids in stress coping
In animals what is isolation linked with?
Psychiatric disorder.
Define affiliation.
Social bonding: this encompasses both sexual and familial relationships.
Define stress.
An actual or anticipated disruption of homeostasis or threat to well-being.
The hypothalamus is associated with the ‘4 Fs’. What are they?
- Fighting
- Fleeing
- Feeding
- Fucking (reproduction)
Basically is involved in all the drives.
Why is conspecific recognition essential?
In order to carry out the appropriate behavioural response.
Why is a ‘social memory’ important?
So an individual can display the proper behaviours to each member of a social group.
Define affiliation.
Social bonding involving connection: this encompasses both sexual and familial relationships.
Why are inter-sex relationships often affiliative?
Allows for reproduction, pair-bonding and parental care.
In animals, social processing is largely driven by olfactory information. How?
Pheromones are released by individuals that are sensed by the vomeronasal organs of others. This then relays information about that individual to the accessory olfactory bulb.
Do humans have vomeronasal organs?
No, it regresses during foetal development.
In 2001 Insel and Young studied social memory. What were the 2 scenarios in their experiment?
- A subject animal is exposed to a stimulus animal. After a period of time the subject is then exposed to the previous or to a new stimulus animal.
- Upon re-exposure the subject animal is presented with the previous and novel stimulus animals simultaneously.
In 2001 Insel and Young studied social memory. What did the first scenario in the experiment test?
Social recognition: the subject spent more time investigating the novel stimulus animal as it recognised the old one.
In 2001 Insel and Young studied social memory. What did the second scenario in the experiment test?
Social discrimination: the subject was forced to choose between the old and new stimulus animals.
In 2001 Insel and Young studied social memory. They used prairie and montane voles:
a) Which species spent more time in the partner chamber (old stimulus animal)?
b) Why?
a) Prairie voles
b) Prairie voles are monogamous and montane voles are polygamous. Thus it can be inferred that the prairie vole bonded more with the stimulus animal.
Prairie voles and montane voles are monogamous and polygamous respectively. What can be said about their oxytocin and vasopressin receptors in the brain?
Both species have varying distributions of each receptor. Oxytocin receptor distribution varies in the nucleus accumbens and vasopressin receptor distribution varies in the ventrum pallidum.
What drives prairie vole monogamy? Does it vary between the sexes?
Oxytocin and vasopressin.
Oxytocin is important in females and vasopressin in males. It is needed to enforce partner preference after mating.
What happens when blockers are applied to a) oxytocin and b) vasopressin after mating in prairie voles?
a) Blocking oxytocin prevents attachment by the female to her boi
b) Blocking vasopressin prevents attachment by the male to his gal
Blocking the hormones prevents monogamy as neither of the pair feel affiliated with their partner.
Where are oxytocin and vasopressin made? Where do they go?
In the hypothalamus: they are then transported to the posterior pituitary gland and released into the blood.
In Autism and Asperger Syndrome (ASD), patients are characterised by abnormalities in social recognition and communication as well as repetitive behaviour. What causes ASD?
Decreased oxytocin in circulation and abnormal oxytocin and vasopressin gene expression.
In an experiment by Heinrich et al. in 2009, subjects were given an intranasal fusion of oxytocin during a facial recognition test. What effect did it have? What does this suggest?
The subjects increased in performance: oxytocin is implicated in social recognition.
In an experiment by Heinrich et al. in 2009, subjects were given an intranasal fusion of vasopressin during a facial recognition test. What effect did it have? What does this suggest?
It did not increase performance, however subjects reacted in the same way to neutral faces as control subjects did to angry faces. Vasopressin is thus implicated in social recognition.
Using the results from Heinrich et al. 2009, and the causes of ASD, why is it that ASD patients have problems with social recognition?
They probably have decreased oxytocin and increased vasopressin expression. They cannot recognise many faces and perceive others to be aggressive when they are not.
Oxytocin ‘facilitates propagation’. Give examples of what it does in a) childhood, b) adolescence, c) adulthood and d) birth.
a) Involved in maternal bonding
b) Involved in social interaction and play
c) Involved in aggression, sex and bonding/mate choice
d) Induces uterine contractions and lactation
Explain Harlow’s ‘substitute mother’ experiments with monkeys in the 1950s and 60s.
He separated baby monkeys from their mothers 6-12 hours after birth. He then gave them the choice of 2 alternative ‘substitute mothers’: a hard wire one and a soft cloth one. Both ‘substitute mothers’ were non-nutritive.
What did Harlow find in his substitute mother experiments?
The baby monkeys always preferred the cloth mothers.
Define attachment.
An affection or fondness for something.
What might drive attachment in non-human animals? Give 3 reasons.
- Proximity seeking
- Social preference
- In response to separation
What might drive attachment in humans?
Love.
Describe what happened in Harlow’s isolation experiments with monkeys in the 1950s and 60s.
He put monkeys in isolation at a young age and thus deprived of a primary caregiver. They became depressed. As adults the social interactions of these monkeys was severely disturbed.
What can cause prenatal stress?
Intrauterine under-growth, resulting in babies of low birth weight.
What can cause postnatal stress in humans?
Any event that puts strain on social relationships, e.g. war, famine, low socioeconomic status etc.
There are 2 systems that elicit the stress response. What are they?
- The autonomic nervous system (ANS)
2. The hypothalamic-pituitary-adrenocortical (HPA) axis
How does the ANS respond to a stressor (stress stimulus)?
The sympathetic and parasympathetic pathways produce rapid physiological responses that are short-lived.
How does the HPA respond to a stressor?
Increases the release of glucocorticoids into the blood plasma. This a slower, longer-lasting response.
Define a glucocorticoid.
A type of steroid hormone involved in the metabolism of macronutrients and the inflammatory response.
In the ANS, what roles do the a) sympathetic and b) parasympathetic pathways have in stress? What are their primary neurotransmitters?
a) Responds to stress with adrenaline
b) Tries to lower stress with acetylcholine
Where is adrenaline produced?
In the adrenal glands above the kidneys.
What activates the HPA axis?
The amygdala, which is the major component in fear-processing.
What shuts down the HPA axis to return the body to homeostasis?
Several feedback loops through structures like the adrenal glands, hypothalamus, hippocampus and prefrontal cortex.
Define a mineralocortoid.
A steroid hormone involved in maintaining salt balance within the body.
Where are both gluco and mineralocortoids released from?
The adrenal cortex, the outer part of the adrenal glands.
What causes the adrenal glands to begin producing corticoids?
The HPA axis.
What causes the adrenal glands to begin producing corticoids? Give 3 steps.
The HPA axis:
- The hypothalamus releases CRH (corticotropin-
releasing hormone) and AVP (arginine vasopressin). - This causes the pituitary to release ACTH (adrenocorticotropic hormone)
- ACTH acts on the adrenal glands that produce corticoids
What is the sympathetic adreno-medullary system involved in?
The fight or flight response.
How does the HPA respond to stress?
The gluco and mineralocorticoids bind to receptors which regulate the release of CRH and ATCH, thus regulating their own release.
Why can the effects of gluco and mineralocorticoid release often be long-lasting?
They bind to TSFs which can permanently alter gene expression.
