Week 8- HPA Axis

Question 1

Structures

Answer 1

Hypothalamus, anterior pituitary, ACTH, Adrenal cortex, cortisol

Question 2

Acute vs prolonged stress and associated brain areas

Answer 2

Acute= sympathetic nervous system

prolonged stress= hpa axis: hormone regulated, slower acting/longer effects

Question 3

Stress response process from amygdala through endocrine components, hormones, and how hormones are regulated

Answer 3

• Amygdala activates hypothalamus within limbic system
• Hypothalamus releases CRH
• CRH triggers pituitary gland, which releases ACTH
• Thyroid and adrenal gland are triggered to release hormones
• Hormones are released broadly in body to mobilize energy (metabolism) and immune system.

Question 4

Effects of stress

Answer 4

Brief or moderate stress
Improved attention and memory formation
Improved performance on simple tasks
Impaired performance on complex tasks that require cognitive flexibility
Enhances immune system
Prolonged stress
Impaired memory
Impaired immune activity

Question 5

Epigenetics

Answer 5

Potentially heritable changes in gene expression, but not involving changes to underlying DNA sequence
Change in phenotype, not genotype
How genes are expressed
Methyl groups & histones- epigenetic tags

Question 6

Resilience

Answer 6

Resilience in the face of stress correlates with strong connections between amygdala and prefrontal cortex

Question 7

James Coan

Answer 7

Hypothalamus- stress hormones
Much less active when you are holding the hand of a loved one
Quality of relationship has a huge effect
Comparable to taking a drug
Happy relationships as protective factors for illnesses and illness recovery
Humans as social creatures
Emotion and emotional regulation in social context
Limits of down-regulation model

Question 8

oxytocin

Answer 8

Produced in hypothalamus
“Tend and befriend”
High levels in bonding and social affiliation
But oxytocin levels are also high under stressful conditions, such as social isolation and unhappy relationships.
In low stress - rewards those who maintain good social bonds with feelings of well-being
In high stress- may lead people to seek out more and better social contacts

Question 9

HPA and memory

Answer 9

Exposure to emotional salient stimuli
Amygdala signals LC to release NE
NE is released to the basolateral nucleus of the amygdala (BLA)
BLA modulates memory processing in the hippocampus
BLA modulates visual cortex (visual processing; fusiform gyrus)

PTSD