PSYC23H3 Lecture Notes - Lecture 3: Inferior Frontal Gyrus, Neuroprotection, Anxiolytic
PSYC23
LECTURE 3
Today Continued
● Child SES effects
○ Physical and mental health
○ Fearful bias and fight-or-flight system revved up
○ Brain development
● Break 10 min
● Can Children Adapt to Adversity
○ Resilience: Kuai Study
○ Self-control
● Can Society Reduce Adversity and Poverty
○ Universal income or basic income
○ Compensation for survivors of social atrocities
Effects of Early Experience: Animals
● Michael Meaney’s research with rat pups
○ Variation in nurturing experience leads to behavioural and physiological/endocrine differences in
pups
■ Lactating mother rats differ in how much they lick/groom their pups
■ Pups with low-nurturing moms have more HPA arousal to stress, greater emotionality,
worse cognitive functioning as adults
■ Nurturing altered endocrine response to stress
○ Cross-fostering paradigm (low-nurturing moms given pups of high-nurturing moms to rear, and vice
versa)
■ Low-nurturing affects expression of gene for glucocorticoid receptor in hippocampus via
CRF repositivity -- even though DNA doesn’t change
■ High-nurturing offspring have greater glucocorticoid receptor expression in hippocampus
→ more negative feedback inhibition → less response to stress
Longer-Term Effects
● Infants exposed to adversity/neglect/abuse
○ Show increased defensive responses:
increased
emotional, automatic, and stress responses
○ Defensive responses are adaptive in short-term BUT
are harmful to health in long-term
■ Chronic activation of defensive responses
associated with diabetes, coronary illness,
mood disorders, etc
○ Meaney’s rats with high nurturing moms
■ As adults, less fearful in new environments
■ More glucocorticoid receptors in hippocampus
■ Better regulation of glucocorticoids (cortisol)
■ Enhanced GABA inhibition in amygdala
Generation Effects
● Effects on maternal behaviour
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LECTURE 3
○ Female rats who had low nurturing as infants show less nurturing of their own pops (treat them how
you were treated)
■ More fearful
■ Biological or behavioural transmission?
● Negative effects of low nurturing moms can be reversed if pups are brushed
○ Stroking with a brush in first week of life increases pup’s hippocampal glucocorticoid receptor
expression
○ Stroking in infancy increases expression of maternal behaviours in adult rats in response to ovarian
hormones
○ Up to a certain age, the effects can be reversed: CRITICAL PERIOD
■ You can’t miss the critical period
■ Biology becomes behaviour and behaviour becomes biology
Can Adversity be Inherited?
● How can one genetically inherit something?
● Can we do that over one or two generations?
Study of Holocaust survivors finds trauma passed on to Children’s genes
● Berlin
○ This gate is at centre, monitors where everyone is
○ Giant machine gun
Panopticon
● Set up so that everyone thinks they’re being
watched at all times
Intergenerational Transmission of Trauma
● 32 Jewish men and women
○ Survived Nazi concentration camp
○ Witnessed or experienced torture
○ Hid during second world war
● After the war was over, went on to have children
● Stress-related regions of the genes of these children were chemically
(epigenetically) altered
○ Wanted to see methylation on gene (same gene in rat study)
○ In same way that trauma typically is known to alter these
genes
Holocaust Video:
● Children of Holocaust survivors experienced anxiety and stress
● They were predisposed to depression and anxiety
○ Response to parental anxiety
● After effects of her parents’ trauma?
○ FKBPs
■ Risk for depression and PTSD
○ Epigenetic change in this same gene
■ 1st generation
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LECTURE 3
■ 2nd generation
■ = response to the events of the trauma
● 2 generations malnutrition, effects of malnutrition could be seen (Holocaust)
Experience transmitted across several generations
● Genetic inheritance vs. epigenetic inheritance
How can an experience affect you if you can’t remember it?
Can memories be passed down from our distant relatives?
● Instincts and inherited behaviours represent a kind of learning and memory that help us survive:
○ Fight or flight
○ Parenting
○ Tend or befriend
○ Sexual or reproductive
○ Empathy or prosociality
Do informative experiences have to be experienced by you to affect you?
● Mice taught to fear a certain smell pass this info onto their children through their sperm (Science
,
2014)
● They underwent fear conditioning
○ Neutral smell + shock = fearful memory
● They had offspring who didn’t have contact with, offspring had also been conditioned
● Traumatic experience passed on from one generation to the next even though there wasn’t any
contact
Can social hierarchies kill you?
Socioeconomic Status (SES)
Background on SES-Health Gradient
● Question: why does poverty make you sick and at risk for
mental health problems?
● Answer a question with a question: It’s due to stress but
let’s first be sure it is not because of medical access?
What else could be causing the SES-health gradient?
● Yes, it’s most likely due to stress
● Two aspects of stress
○ Objective: Exposure to more stressful events
that require greater adaptation
■ Divorce
Document Summary
Variation in nurturing experience leads to behavioural and physiological/endocrine differences in pups. Lactating mother rats differ in how much they lick/groom their pups. Pups with low-nurturing moms have more hpa arousal to stress, greater emotionality, worse cognitive functioning as adults. Cross-fostering paradigm (low-nurturing moms given pups of high-nurturing moms to rear, and vice versa) Low-nurturing affects expression of gene for glucocorticoid receptor in hippocampus via. Crf repositivity -- even though dna doesn"t change. High-nurturing offspring have greater glucocorticoid receptor expression in hippocampus. More negative feedback inhibition less response to stress. Show increased defensive responses: increased emotional, automatic, and stress responses. Defensive responses are adaptive in short-term but are harmful to health in long-term. Chronic activation of defensive responses associated with diabetes, coronary illness, mood disorders, etc. Female rats who had low nurturing as infants show less nurturing of their own pops (treat them how you were treated) Negative effects of low nurturing moms can be reversed if pups are brushed.
