Class 10 - Stress: Epigenetics, neuroalterations, and mental health Flashcards
(61 cards)
1
Q
What are the 2 dimensions of childhood adversity?
A
threat and deprivation
2
Q
In the romanian institutionalization study, what was found about children who remained institutionalized for longer (3)?
A
- blunted cortisol response to acute stress
- elevated cortisol throughout the day
- more synchronicity btw HR and breathing (not good; want to be able to breathe slow when HR high)
3
Q
The promoter region of a DNA sequence contains _____
A
transcription factor binding sites
4
Q
What is RNA polymerase? Where does it bind?
A
- enzyme responsible for synthesizing an RNA molecule from DNA template during transcription
- binds to promoter region w assistance of transcription factors
5
Q
more RNA molecules observed is an indication that ___
A
the gene is active (there is gene transcription)
6
Q
What is the translation phase in genes? Where does it take place?
A
- RNA sequence produced in transcription is translated to proteins
- mRNA binds to ribosome which decodes its sequence to produce proteins
- takes place in cytoplasm (outside nucleus)
7
Q
Epigenetics is the study of how ___ and ___ can cause changes that affect _____
A
behaviours and the environment can affect the way your genes work
8
Q
(T/F) epigenetics involves editing of genes
A
FALS, changes expression, not the genes themselves
9
Q
What are the two most common forms of epigenetic mechanisms?
A
DNA methylation and histone modifications
10
Q
What are the 2 types of histone modifications?
A
- acetylation (unfolds DNA; makes more accessible for transcription so increases gene expression)
- deacetylation (coils DNA; less accessible for transcription so less gene expression)
11
Q
What are histones?
A
- proteins that structure DNA
12
Q
(histone modification/methylation) is a more precise form of epigenetics
A
methylation
13
Q
Coiled DNA means (increased/decreased) gene expression
A
DECREASED
14
Q
What is DNA methylation?
A
- methyl group binds to cytosine (C) in DNA
- acts as physical barrier preventing binding of transcription factors to promoter region
- more methylation = less gene expression
15
Q
What is the Developmental Origins of Health and Disease hypothesis (DoHaD)?
A
- environmental exposures during critical periods of prenatal/early postnatal dev can influence long-term health outcomes
16
Q
What is wrong with the quote from the Time magazine cover: “The new science of epigenetics reveals how the choices you make can change your genes - and those of your kids”
A
- epigenetics can’t “change” genes, just how they function
17
Q
(T/F) all methylation is passed on to the child via reproduction (explain!)
A
FALSE, most gets erased during gametogenesis but “imprinting control regions” of genome escape reprogramming and maintain parental methylation patterns
18
Q
In agouti mice, the agouti gene is always turned (on/off). Methylation of the agouti gene is ass w (activation/deactivation) of agouti gene AND a change in phenotype (fur colour)
A
- always ON
- ass w DEACTIVATION of agouti gene
19
Q
What happens to offspring when a pregnant agouti mouse is fed a diet of methyl supplementation?
A
- offspring mostly not agouti mice
20
Q
What was the study that inaugurated the field of neuroscience epigenetics?
A
- Michael Meany
- was able to categorize epigenetic programming by maternal behavior (in rats)
21
Q
What were the findings of Michael Meany’s study on epigenetic programming by maternal behavior?
A
- maternal care evokes changes in DNA methylation and chromatin structure!!
- good maternal care increases GR gene expression (helps w negative feedback system of HPA axis)
- changes could be reversed by cross-fostering to low care mothers!
22
Q
How can we translate epigenetic findings in humans?
A
- examine brain post mortem
23
Q
What did researchers find in the postmortem brains of suicide victims w history of childhood abuse vs no history?
A
- decreased levels of glucocorticoid receptor (GR) mRNA
- increased methylation of promoter region for GR
24
Q
How do we know that there is low transcription of glucocorticoid receptors (impeding neg feedback of HPA axis) in live children who are victims of maltreatment?
A
- looked @ methylation patterns in blood
25
Prenatal stress alters the (structure/function) of the brain, especially in the ____, ____, and ____
- structure AND function
- hippocampus, amygdala, and prefrontal cortex
26
Elevated cortisol during early pregnancy are ass w increased _____ development in the fetus and poor ____ in (girls/boys) before puberty
- increased right amygdalar dev
- poor emotional dev in GIRLS
27
What enzyme mediates stimulatory effects of tactile contact in facilitating growth and development?
ornithine decarboxylase (ODC)
28
(T/F) pups can get ornithine decarboxylase via milk
FALSE, need physical contact!
29
What is one implication of the importance of ornithine decarboxylase in growth for human babies?
- practice of stimulating growth and dev in preemies by increasing handling (skin to skin contact)
30
What is psychosocial dwarfism?
- syndrome in infants who experience little/no physical contact
- compromised growth and development despite adequate nutrition
- disrupted GH secretion and absence of tissue responsiveness to exogenous GH
31
What is the link between attachment style and stress response?
- secure attachment = more adaptive stress response
- less cortisol in acute stress and quicker rebalancing
32
What are 3 findings about the benefits of secure attachment in the cortisol response?
- less cortisol after inoculations
- buffers effects of poverty
- interventions on parent-child relationship can improve cortisol response
33
attachment security (moderates/mediates) the relationship between _____ and ______
moderates; childhood experience and cellular aging
34
IN ANIMALS:
- females have (greater/weaker) basal concentrations of corticosterone
- females secrete (greater/weaker) concentration of corticosterone in response to stressors
- adrenal gland is larger in (males/females)
- females have GREATER basal concentrations of corticosterone
- females secrete GREATER concentration of corticosterone in response to stressors
- adrenal gland is larger in FEMALES
35
It seems that sex differences in stress hormones are ______, rather than _____, by hormones
activated rather than organized
36
IN HUMANS:
- (men/women) face more stressors
- stress affects attention and cognitive function more in (men/women)
- (men/women) are more likely to experience childhood trauma and suffer higher lvls of childhood stress
- WOMEN face more stressors
- stress affects attention and cognitive function more in MEN
- WOMEN are more likely to experience childhood trauma and suffer higher lvls of childhood stress
37
(T/F) stress inhibits testosterone production in men
TRUE, leads to reduced sexual motivation and performance
38
In men and women, glucocorticoids at high concentrations can suppress ___ and ___ secretion
GnRH and LH
39
How can social status in males impact the role of stress on reproduction?
- dominant males have higher lvls of enzyme that counteracts elevated glucocorticoid concentrations to ensure fertility!
40
What is the effect of exercise on stress in males?
- moderate exercise increases T
- mild exercise counteracts effects of stress
- excessive exercise acts as stress and causes sustained glucocorticoid secretion leading to low T conc
41
How does stress lead to erectile dysfunction?
- stress makes it difficult to establish parasympathetic activity in the penis (bc of stress-induced high sympathetic output)
- need parasympathetic activation for erection, sympathetic should only come online during ejaculation
42
What are 2 potential hormonal consequences for women who are very stressed or exercise excessively?
- amenorrhea
- less frequent LH pulses
43
How can fasting act as a stressor?
- increases blood glucocorticoid conc
44
What is hyperandrogenism?
- mechanism of reproductive impairment in females
- caused by overactive adrenal cortices and androgens
- increased androgen conc disrupts negative feedback mechanisms of GnRH and gonadotropins
- can cause acne, male pattern balding, abnormal hair growth, virilization
45
What is the function of the hippocampus in the stress response? How is it altered by chronic stress?
- helps shut off stress response (inhibits HPA axis)
- structural changes: fewer connections, smaller volume
- functional changes: diff w memory, learning
46
What is the function of the prefrontal cortex in the stress response? How is it altered by chronic stress?
- helps shut off stress response (inhibits HPA axis)
- structural changes: fewer/altered connections
- functional changes: difficulty regulating thoughts, emotions, behaviour
47
What is the function of the amygdala in the stress response? How is it altered by chronic stress?
- turns on stress hormones and increases HR
- structural changes: altered connections and volume
- functional changes: hyperreactive stress response
48
Affective disorders are often characterized in terms of a ___
continuum
49
How is the HPA axis affected in depression?
- negative feedback system impaired
- higher blood conc of cortisol!
50
What is the link between depression and thyroid hormones?
- depressed ppl have low thyroid function
- treatment of depression w thyroid hormone supplementation is only effective in patients w hypothyroidism
51
What is the link between depression and estradiol?
- women w past perimenopausal depression show improvement in depression symptoms when treated w estradiol
52
What 3 hormonal/neurological changes are associated with PTSD?
- disregulation of HPA axis (blunted stress resp)
- reduced hippocampal volume
- deficits in short-term memory
53
How does SAD affect hormones?
- cyclic disruptions in serotonin-carbohydrate regulating mechanisms
- display more serotonin transporter activity in fall/winter which leads to less available serotonin in synaptic cleft
54
How are carbohydrates linked to hormones?
- tryptophan is converted to serotonin in brain
- when we eat carbs, pancreas secretes insulin which facilitates uptake of sugars and non-tryptophan amino acids to peripheral cells
- leads to higher tryptophan in blood which means more tryptophan crosses blood brain barrier leadings to higher production of serotonin
- serotonin ass w decrease in appetite
55
What is the best treatment for SAD?
- light treatment to try to change circadian rhythms
- only works in conjunction w dietary adjustments
- exposure should be a few hours in the morning
56
What are 6 possible physical problems of anabolic steroid use in MEN?
- baldness
- headaches
- dev of breasts
- enlarged prostate
- reduced sperm count
- shrinkage of testicles
57
What are 5 possible physical problems of anabolic steroid use in WOMEN?
- increase in facial and body hair
- deepened voice
- reduced breast size
- menstrual problems
- enlarged clitoris
58
What psychiatric symptom is common among abusers of androgens?
mania or hypomania
59
What are 12 physical problems ass w anabolic steroid use in both men and women?
- 2 behavior/mood
- 1 skin
- 1 heart
- 1 liver
- 3 tummy
- 1 sexual organs
- 1 circulation
- 2 movement/body
- aggressive behavior
- mood swings
- severe acne
- high BP and heart disease
- liver damage
- nausea
- bloating
- urinary and bowel problems
- sexual dysfunction and infertility
- strokes and blood clots
- aching joints
- increased risk of tendon injuries
60
What are 4 psychological variables that modulate stress physiology?
- control
- predictability
- outlets for frustration
- habituation
61
