W8_02 Anxiety Flashcards
describe the low road fear pathway
visual/auditory sensation;
thalamus;
amygdala;
hypothalamus
describe the high road fear pathway
visual/auditory sensation; thalamus; visual/auditory cortex; frontal cortex; amygdala; hypothalamus
which receptor is responsible for long term potentiation/depression?
NMDA receptor causes up/downregulation of the AMPA receptor
what is the role of catecholamines in the brain?
carry meta information. can modify the response to other neurotransmitters.
where does serotonin come from in the brain?
raphe nuclei
where does dopamine come from in the brain?
ventral tegmental area
activity in the amygdala is experienced as what emotion?
fear/anxiety
where are fear-context associations stored in the brain?
amygdala in conjunction with the hippocampus
conscious vs unconscious fear?
amygdala gives a general vague sense of fear because it’s subcortical
what are three general types of pathological anxiety?
panic attacks; generalized anxiety disorder; phobias; OCD; PTSD; acute stress disorder
name symptoms of panic
tachycardia; sweating; trembling; shortness of breath; choking; chest pain; nausea; dizziness; fear of going crazy; fear of dying; parasthesia; flushes; derealization; depersonalization
what are three neurotransmitters involved in anxiety?
norepinephrine, serotonin, GABA
where are the structural abnormalities in anxiety?
amygdala, hippocampus, cortex, and their connections
dopamine uses which type of receptor?
GPCR
what’s the timeline of SSRI treatments?
initially exacerbate anxiety by increasing serotonin;
panic attacks reduced over 2-4 weeks;
we believe receptors are downregulated
where in the brain does norepinephrine come from?
locus ceruleus
yohimbine and caffeine act on what? what clinical effect do they have?
act on locus ceruleus to produce increased anxiety
which structure does benzodiazepines and imipramine affect?
the locus ceruleus
citalopram, fluoxetine, paroxetine, sertraline, fluvoxamine are examples of which class of drugs?
SSRIs
-ipramines and nortryptiline are examples of which class of drugs?
tricyclic antidepressants
venlafaxine, desvenlafaxine, duloxetine, are examples of which class of drugs?
serotonin norepinephrine reuptake inhibitors
mechanism of action for benzodiazepines?
binding to GABA_A receptors increases their conduction to chloride;
hyperpolarization and less excitability
effects of benzodiazepines?
sedation, relaxation, disinhibition, amnesia, anticonvulsant
fact: benzodiazepines are lipophilic due to multiple rings, so can cross BBB easily
good
mechanism of action for tricyclic antidepressants?
increase NE by binding to NE and 5-HT reuptakers, but cause down regulation of NE receptors
describe the cycle of avoidance
situation provokes anxiety;
escape provides relief like reward system;
thoughts of being in the situation again creates more anxiety;
generalization occurs when thoughts of related situations also cause panic
how does conditioned fear work in humans?
any stimuli at time of attack will become conditioned fear stimuli;
stimuli generalize;
may worsen to agoraphobia
fact: exposure therapy reduces anxiety
good
how does gradual exposure work?
patient ranks top 10 anxiety-causing things. exposure therapy for each and slowly increase in severity until they get over them
fact: extinction does not erase fears. it teaches the cortex to inhibit them.
good
what does CCK do in the brain?
CCK receptor agonists provoke panic attacks. activate amygdala and cingulate gyrus
fact: recall the mouse grooming example of epigenetic modification
attentive moms produce pups that are less fearful and have less HPA axis activation
