Class 9 – Early life adversity, hormones and mood

Question 1

What 4 types of hormones are linked to ELS?

Answer 1

• Thyroid
• Glucocorticoids
• Ovarian hormones
• Insulin

Question 2

(T/F) as early as 1934 we had models explaining the impacts of early life stress on human development

Answer 2

FALSE, knew there was a problem but didn’t know what was going on

Question 3

Harlow’s research w monkeys provided evidence that ___ is as, if not more, important as nutrition in early life

Answer 3

care and comfort

Question 4

What did David Barker discover? What are 2 limitations of his research?

Answer 4

• odds ratio for metabolic syndrome varied as a function of birth weight
• babies born small are at increased mortality risk at any age
• limitations: just correlation, only looked at birth weight as predictor (not other things like gestational age)

Question 5

What is HPA axis programming?

Answer 5

idea that early life stress can permanently affect functioning of the HPA axis

Question 6

What happens when stressors occur during sensitive periods of development?

Answer 6

they can disrupt developmental slope and leave permanent mark in functioning of that system

Question 7

When does the HPA axis develop in humans?

Answer 7

in the first few months of life

Question 8

What did research on maternal care and stress response in grown rats find?

Answer 8

• takes longer to shut down stress response in low care group (issue with negative feedback)
• found lower glucocorticoid receptors in hippocampus in low care group (which would lead to issues w negative feedback!)
• caused by increased methylation levels which impacted gene expression of GR gene (which produces glucocorticoid rec.)

Question 9

(T/F) early research of impacts of ELS on rat hippocampus were replicated in humans

Answer 9

TRUE

Question 10

What do we see in the cortisol response of human babies with low birth weights? What are the implications long-term?

Answer 10

• increased response to acute stress
• this happens every time they experience stress which leads to chronic exposure to glucocorticoids

Question 11

What are 5 conditions those who experience ELS (chronic exposure to glucocorticoids) are at increased risk for?

Answer 11

• obesity
• hyperglicemia/insulin resistance (T2 diabetes)
• artherosclerosis
• hypertension
• psychiatric conditions (and poor cognition)

Question 12

Acute stress is usually ___, the problem is when it becomes ___.

Answer 12

adaptive; chronic

Question 13

What are 6 perinatal events that can program HPA axis activity?

Answer 13

• intrauterine growth restriction (small birth weight)
• chronic diseases during pregnancy
• natural variations in maternal care
• use of glucocorticoids during pregnancy
• smoking during pregnancy
• postnatal stress

Question 14

What effects do we see in the grown up pups of mothers who had reduced material for nest building (3)? What is this an example of?

Answer 14

• more anxious behaviour in adulthood!
• respond more to stress (more ACTH and corticosterone in response to acute stress)
• alterations in secretion of T3/T4 (HPT axis also affected; links to anxiety and depression)
• example of programming of HPA axis by postnatal stressor!

Question 15

About __% of babies are affected by intrauterine growth restriction (IUGR)

Answer 15

10% (probably more)

Question 16

What causes intrauterine growth restriction (IUGR)?

Answer 16

• diff diseases in pregnancy (hypertension, obesity, diabetes) lead to placenta not working well
• so even if mom is getting right nutrients they can’t get to baby

Question 17

What are 4 long term risks for IUGR?

Answer 17

• type 2 diabetes
• cardiovascular disease
• mental health issues (psychopathology)
• increased mortality risk at all ages

Question 18

What are the results of altered brain insulin function in kids and teens who were born small (3)?

Answer 18

• more impulsive to palatable foods in childhood (esp girls)
• increased intake of palatable foods
• teens activate more areas of inhibitory control for unhealthy food (have to work harder to resist)

Question 19

Insulin receptors in the brain primarily have a ____ role

Answer 19

neuromodulatory

Question 20

What is catch-up growth and how does it happen?

Answer 20

• babies born small have smaller pancreas to less insulin prod
• born w high insulin sensitivity which means they use increased glucose
• increased use of glucose leads to fast growth after first few months ish

Question 21

The degree of catch-up growth reflects the degree of ____

Answer 21

alteration in insulin secretion

Question 22

What is the link between degree of catch-up growth and impulsivity?

Answer 22

• as catch-up growth increases, we see increases in impulsivity ONLY in those born small
• finding replicates across different cohorts

Question 23

How can the adult insulin fasting genome-wide association study be used to inform current research projects?

Answer 23

• can use to create polygenic score ass w fasting insulin levels

Question 24

What were the findings of the study looking at impact of polygenic risk for fasting insulin levels and postnatal adversity on impulsivity?

Answer 24

• increases in adversity lead to increases in impulsivity ONLY in kids w higher genetic risk for higher fasting insulin

Question 25

We have evidence for alterations in resting state connectivity of the ___ (which is involved in ___) in children and teens who were born small

Answer 25

orbitofrontal cortex, involved in decision making

Question 26

What were the results of the study that gave cafeteria vouchers to teens who were born small vs normal?

Answer 26

• born small gave back more money
• spent less but had same calories (means they picked junk food)