Stress 2 Flashcards
True or False?
The release of Adrenaline acts with noradrenaline
True
What does noradrenaline do?
Noradrenaline prepares the brain & body for action
Define a noradrenaline
A neurotransmitter of the brain that plays an essential role in the regulation of arousal, attention, cognitive function, and stress reactions
Noradrenaline is lowest in …. and highest in….?
Lowest = Sleep
Highest = During stress
Where is noradrenaline primarily released from in the brain?
Locus Coeruleus
What is the brain neurotransmitter that works alongside adrenaline?
Noradrenaline
As a neurotransmitter, Noradrenaline can enhance ….?
Formation and retrieval of memory
True or False?
Early events cannot affect how we respond to stress
False
Early events can affect how we respond to stress
What caused prenatal stress during the end of WW2 (Dutch Hunger Winter)?
- Nazis pushed back against the Dutch
- The Dutch tried to aid the Allies for liberation
- As punishment, Nazis cut off all food
transport (5 months) - After the liberation, there was a sudden increase in food
What was the typical food consumption during the Dutch Hunger Winter?
400-800 calories/day
What were the effects related to health after the Dutch Hunger Winter?
Cohort of people with increased risk of heart disease, type 2 diabetes aged 50 years
What were the effects related to prenatal development and stress after the Dutch Hunger Winter?
- Fetus ‘learns’ that food is scarce
- Metabolism of the fetus has permanent shift = “Metabolic imprinting”
- Afterwards, the fetus becomes good at storing consumed food and retaining salt from its diet
- Developed ‘thrifty’ metabolism
What did Kajantie et al. discover about the link between birthweight and cortisol levels?
The lower the birthweight (adjusted for height), the higher the basal cortisol levels in adults (particularly for premature birth)
What did Kajantie et al. do in their study investigating the link between birthweight and cortisol levels?
1) Large cohort study of 421 men, born 1924-33
2) Birthweight & size was recorded, evaluated cortisol levels aged ~70 years
The lower the birthweight (adjusted for height), the higher the basal cortisol levels in adults (particularly for premature birth)
What does this suggest about stress?
Early exposure to stress programs your stress-reactiveness
When pregnant rats experience significant stress, how are their offspring affected?
Prenatally stressed rats show:
1) Freezing in bright lights, difficulties learning & taking longer to socially interact
2) All evidence of greater anxiety
3) Amygdala shows greater glucocorticoid receptors
What did Plotsky and Meaney do in their study investigating postnatal stress?
1) Maternal separation of rats
2) As adults, the rats showed increased glucocorticoid response to stress and greater fearfulness
Stress in infancy can increase growth hormones and increase adult height
True or False?
False
Stress in infancy can reduce growth hormones and lower adult height
What did Gunnar et al. do in their study investigating Romanian orphanages and stress levels?
1) Compared daytime cortisol measures in children from:
- Romanian orphanages for > 8 months
- Romanian orphanages for <= 4 months
- Canadian children
2) Studied children at 7-8 years old
What did Gunnar et al. discover in their study investigating Romanian orphanages and stress levels?
Cortisol levels of children in Romanian orphanages for > 8 months were higher than the cortisol levels in children who were adopted early and Canadian children
True or False?
Only prenatal events can affect the production & baseline rates of stress hormones (e.g. cortisol)
False
Both prenatal and postnatal events can affect the production & baseline rates of stress-hormones (e.g. cortisol)
True or False?
Perceived threats can trigger a stress response
- HPA axis
- Release of adrenaline & noradrenaline from the adrenal medulla and brain
True
What are the 3 main questions we ask when we’re studying the effects of stress in adults?
1) Which brain areas are involved in perceiving threats?
2) Which brain areas help to regulate these emotions?
3) How can we study stress in adults
(Physical stress or Psychological stress)
What did Nili et al. do in their study investigating stress levels and phobias?
1) Recruited people with snake phobias
2) Put a group of Ps in an MRI scanner with snakes and a control group of Ps with a toy bear
3) Allows the Ps to control the distance from the object (snake or toy bear) on the trolley
4) At each point, Ps chose whether to bring the live snake closer or further away from them
What did Nili et al. discover in their study investigating stress levels and phobias?
1) When either the snake or toy bear was far away, Ps did not care
2) But when choosing to let the snake be closer to them increased brain activity
3) When fearful people chose to advance the snake, amygdala activity was reduced (fear response)
What did Patrick Vuilleumier et al. do in their study investigating how the brain recognises threats in the environment?
1) fMRI study
2) Participants decided:
¤ Are the vertical or horizontal boxes the same
¤ Either faces or houses
¤ Some faces were neutral, others were fearful
What did Patrick Vuilleumier et al. discover in their study investigating how the brain recognises threats in the environment?
Participants were slower at judging houses
if faces happened to be fearful compared to neutral faces
In Vuilleumier et al.’s study, which part of the brain was most active when faces were shown?
Fusiform gyrus
In Vuilleumier et al.’s study, which part of the brain was most active when houses were shown?
Parahippocampal gyrus
What does the Parahippocampal gyrus respond to the most in Vuilleumier et al.’s study?
Houses
What does the Fusiform gyrus respond to the most in Vuilleumier et al.’s study?
Faces
Participants were slower at judging houses
if faces happened to be fearful compared to neutral faces
Why does this happen?
The amygdala was more active when incidentally viewing fearful faces
Facial expressions of fear and anger, which both signal potential threats to an observer, result in significant increases in amygdala activity
This resulted in the Ps focusing more on processing the potentially threatening stimulus (fearful face) over the neutral stimulus (houses)
What are the 3 types of disorders we can look at to examine clinical cases of poor emotion regulation?
1) Post-traumatic stress disorder
2) Social Anxiety Disorder
3) Specific phobia
What did Etkin and Wager do in their analysis investigating brain areas involved in regulating the stress response?
Conducted a meta-analysis of fMRI studies across conditions such as:
1) Post-traumatic stress disorder
2) Social Anxiety Disorder
3) Specific phobia
What did Etkin and Wager’s meta-analysis suggest about Ps brain activity across conditions such as:
1) Post-traumatic stress disorder
2) Social Anxiety Disorder
3) Specific phobia
List 2 observations
Patients showed either:
1) Increased activation in the amygdala (phobia/ social anxiety)
2) Decreased activity in the medial prefrontal cortex (PTSD)
The midline of the brain that is in front of the motor cortex is known as…?
Medial prefrontal cortex
The medial prefrontal cortex is involved in…?
Regulating amygdala activities
What did Etkin et al. do in their study investigating emotion regulation?
1) Examined brain responses to anxiety & fear
2) Investigated which brain regions are active when we consciously control our emotional response
Define emotion regulation
Balancing your emotions
‘Bottom-up’ signalling (senses stimuli from the environment and reacts to it) from the Amygdala indicates ….?
Threats in the environment
‘Top-down’ regulation from the medial pre-frontal cortex prevents …?
Bottom-up signalling from triggering constant stress-responses
What prevents bottom-up signaling from triggering constant stress-responses?
‘Top-down’ regulation from the medial prefrontal cortex
Which part of the brain is considered bottom-up signalling?
Amygdala