Exam 4: Anxiety Part 2

Question 1

hormones and neurotransmitters involved in anxiety (5)

Answer 1

1. CRF (cortisol)
2. NE
3. GABA
4. Serotonin
5. Dopamine

Question 2

Corticotropin releasing factor (CRF)

Answer 2

• released from hypothalamus in response to stress

- CRF causes anterior pituitary to release ACTH which releases glucocorticoids like cortisol from adrenal cortex

Question 3

neurochemistry of CRF - normal person

Answer 3

• glucocorticoids induce changes to adapt to environmental challenges
• inc blood sugar, inc BP
• reduces inflammation/immune response
• mobilizes resources and energy in response to immediate environmental challenge

high cortisol acts as negative feedback to HPA system to bring cortisol levels down to normal

Question 4

CRF interacts with brain regions - anxiety

CRF acts as a ____

Answer 4

CRF neurons originate in amygdala and project to locus coeruleus (NE center of brain) and activate adrenergic component of stress response

CRF release starts to activate arousal networks, inc vigilance

CRF acts as a neurotransmitter

Question 5

Norepinephrine

Answer 5

released at target visceral organs in sympathetic activation
prepares response to danger

NE and epi are important in formation of emotional memories!!!
high NE helps remember that something was a threat

Question 6

what impairs the formation of emotional memories

Answer 6

B-adrenergic antagonists

-propranolol - modifies BP - blocks NE B receptor preventing memory to underly long term causes of PTSD

Question 7

NE and anxiety evidence (4)

Answer 7

-associated with inc activity in locus coeruleus - hyperarousal, hypervigilant

-a2-autoreceptor antagonist Yohimbine can produce panic attacks in PTSD
drugs blocking autoreceptor inhibit further NE release, disinhibiting LC can inc panic attacks

• they have abnormal autonomic nervous system activity - dramatic responses to neg stimuli
• veterans with PTSD have higher than normal NE levels

Question 8

LC projects to ____ that has roles in attention and working memory

Answer 8

PFC

Question 9

activation of a2 autoreceptor in PFC

Answer 9

enhances working memory

Question 10

activation of a1 receptors (excitatory)

Answer 10

deleterious effect on cognitive functions

-overstimulated and now you cannot focus or concentrate

Question 11

for a normal person NE has a higher affinity for what receptors in the PFC

Answer 11

a2 receptors

Question 12

In cases of inc NE, under stress or anxiety what receptor activation is inc

Answer 12

a1 receptor activation inc which can lead to cognitive impairment

Question 13

GABA

Answer 13

gltamatergic neurons from PFC stimulate GABA in the amygdala
-if threat PFC says do not worry and activates GABA

Question 14

GABA and anxiety

Answer 14

impaired GABA function - overactive amygdala activity

glutamate sends to GABA to stop but it cannot - indicating an aversive event

Question 15

where are GABA receptors found in high concentrations (3 areas)

Answer 15

amygdala, limbic system, cerebral cortex)

Question 16

what happens when you walk into a test and you realize you studied for the wrong thing - no PFC

Answer 16

amygdala - omg there is an exam
activates hypothalamus: inc HR
activate brainstem : muscles, tingly, shaky - sympathetic activation, stress response

Question 17

GABA A receptors

Answer 17

ionotropic

Cl- channels open and Cl- enters cell, hyperpolarizing it - dec amount of action potentials

Question 18

benzodiazepines and barbiturates and GABA

Answer 18

they cause sedation and reduce anxiety by binding to allosteric sites on the receptor complex

Question 19

what do patients with panic disorder show on PET scans in relation to benzodiazepines

Answer 19

dec benzodiazepine binding in the CNS - mainly frontal lobes

less binding sites can result in failure of GABA to inhibit resulting in uncontrolled panic attacks, phobias, hyperarousal of PTSD, generalized anxiety

Question 20

serotonin and anxiety

Answer 20

there is a sweet spot between to little and too much serotonin
inc serotonin can worsen anxiety
-inability to control stressor increases activity in the dorsal raphe nucleus!!

Question 21

what serotonin receptor is involved in anxiety

Answer 21

5-HT1A

Question 22

5-HT1A injection in hippocampus or amygdala

Answer 22

receptor is postsynaptically

anxious behaviors increase

Question 23

5-HT1A injection into raphe nuclei

Answer 23

receptors somatodendritic autoreceptors

anxiolytic effect occurs

Question 24

individuals with anxiety show reduced 5-HT1A binding _____

Answer 24

in the raphe

less ability to shut down the serotonin raphe mediated response so you will release more serotonin than needed

Question 25

first line of treatment for anxiety

Answer 25

SSRIs

Question 26

SSRIs what do they do

Answer 26

acutely block reuptake of serotonin - prolonging its effects

• it initially inc anxiety which is why some may stop taking it
• long-term neuronal adaptations are required for its effectiveness - altered pharmacodynamic sensitivity

Question 27

mesocortical DA projects to

Answer 27

VTA and mPFC

Question 28

anxiety and dopamine

Answer 28

stress inc firing of mesocortical DA neurons, inc DA turnover in PFC
-more DA broken down in cortex

Question 29

reducing DA transmission with lesions of VTA … amygdala___

Answer 29

amygdala pathway reduces conditioned fear response and impairs acquisition of avoidance behavior

Question 30

injections of D1 receptor agonists vs D1 antagonists

Answer 30

D1 agonists: inc anxiety

D1 antagonists: produce anxiolytic effects

Question 31

stress initiating phasic burst firing of DA into NAcc

Answer 31

chronic activation when threat is no longer present predicts vulnerability to dysfunctional responses in social interactions in SAD

stressor will feel rewarding -good initially to notice things that are bad - helps you survive