Lecture 16: Neurosciences of Stress

Question 1

what causes stress

Answer 1

an external trigger

Question 2

what is anxiety

Answer 2

persistent, excessive worry that doesn’t go away even in the absence of a stressor

Question 3

what does stress alter

Answer 3

the body’s equilibrium

Question 4

what are the 2 types of stress

Answer 4

physical (injury, hunger, etc)

physchological (deadlines, pressure)

Question 5

what is the Inverted U curve of stress

Answer 5

there is an optimal arousal level where we have optimal performance

if arousal is too low, we don’t have interest and pay less attention

if arousal is too high, performance is impaired

Question 6

what is the relationship between stress and the difficulty of a task

Answer 6

Difficult tasks are performed better during low stress levels; easy tasks are performed better during moderately high stress levels

Question 7

what are the 2 kinds of stress responses

Answer 7

Immediate response (SAM axis)

Slightly delayed response (HPA axis)

Question 8

what is the Immediate response (SAM axis)

Answer 8

happens very quickly

amygdala activates it, sending distress signal to hypothalamus

Epinephrine and norepinephrine are released

Question 9

what is the Slightly delayed response (HPA axis)

Answer 9

Hypothalamus releases CRH

Pituitary gland releases ACTH

Adrenal cortex releases cortisol

Question 10

is the HPA axis is heavily connected to other parts of the brain

Answer 10

Prefrontal cortex (-), hippocampus (-), and amygdala (+)

Question 11

what is the HPA Axis-Negative Feedback Loop

Answer 11

Normally, cortisol produced in the adrenal cortex inhibits the hypothalamus and pituitary gland

Negative feedback loop important for allostasis (homeostasis)

Question 12

what happens in the body when were stressed

Answer 12

Increased heart rate and blood pressure, and faster, shallower breathing, increased availability of glucose

Question 13

are Physical and psychological stressors are processed in the same brain circuits

Answer 13

they are processed in overlapping but different brain circuits

Question 14

what areas in the brain are active during dress

Answer 14

prefrontal cortex, brainstem, and limbic system

Question 15

which axis do physical stressors use

Answer 15

Physical stressors mostly activate autonomic stress responses (SAM axis) for a faster response

Question 16

which axis do psychological stressors use

Answer 16

HPA axis

Question 17

what triggers the SAM axis

Answer 17

Locus coeruleus (LC)

Question 18

what triggers the HPA axis

Answer 18

Paraventricular nucleus (PVN) of hypothalamus

Question 19

what is the main integrator of stress signals

Answer 19

Paraventricular nucleus (PVN) of hypothalamu

Question 20

what part of the brain is in charge when we are alert and in control

Answer 20

prefrontal cortex

Question 21

what part of the brain is in charge during acute stress

Answer 21

high levels of norepinephrine and dopamine switch the control from the prefrontal cortex to the limbic system

Question 22

what is the Impact of Acute Stress on Cognitive Function

Answer 22

detrimental effects of executive function

Activation of the sympathetic nervous system is linked to inflammation

Question 23

how does chronic stress affect the HPA Axis-Negative Feedback Loop

Answer 23

the brain loses its ability to turn off the HPA axis, so its overactive

Chronic activation of the HPA axis can lead to cortisol resistance

Question 24

what is Allostatic Overload

Answer 24

cumulative effect of stressors on the body in both physiological and pathological situations

When environmental challenges exceed the ability to cope

An extreme state where stress responses are repeatedly activated

Question 25

does chronic stress increase risks?

Answer 25

increase risk for disease and early mortality

Question 26

what happens in the brain with chronic stress

Answer 26

Reduced dendritic complexity in the hippocampus and prefrontal cortex

Learning and memory deficits

Possible hypertrophy of the amygdala

Question 27

how is stress associated with mental health

Answer 27

Stress is strongly associated with depression, post-traumatic stress disorder (PTSD), substance use, and anxiety

People with major depression have higher cortisol and smaller hippocampal volumes

Anxiety disorders are more common in those with early life stress

Question 28

how can exercise help with stress

Answer 28

Exercise can downgrade the stress response

Mind body (yoga, etc) exercise may have a larger impact than other forms of exercise

Question 29

why is mind-body exercise good for exercise

Answer 29

Activation of the parasympathetic system

Yoga decreases cortisol, heart rate, and blood pressure

Much larger effect sizes for anxiety

Question 30

what’s happening in the brain with mind-body exercise?

Answer 30

Increased gray matter volume in the insula and hippocampus

Increased activation in the prefrontal cortex

Question 31

what does mindfulness do

Answer 31

has a moderate effect on anxiety

Question 32

what does breath work do

Answer 32

Breathing exercises improved both anxiety and depression

Question 33

what is Five-Finger Breathing

Answer 33

Place index finger and thumb on pinky finger of other hand

As you breathe in, trace up to the tip of your pinky and as you breath out, trace down your pinky

Repeat with each finger for 10 breaths