Fear and Anxiety Flashcards
name the difference between fear and anxiety.
fear is a useful and innate response, whereas anxiety is an inappropriate fear response.
give an example of conditioned emotional response.
- mouse trained to lever press for food.
- CS + footshock
- normal levels of lever pressing for food in presence of NS
3b. reduced levels of ever pressing for food in presence of CS.
how many nuclei does the amygdala contain?
22
define the clever-bucy syndrome.
disorder that occurs when both the right an left medial temporal lobes of the brain malfunction.
when amygdala was removed from temporal lobe, what was the outcome?
lack of fear response.
give evidence that amygdala s involved in fear?
- less amygdala leads to less fear
- increased activation during public speaking in subjects with SAD.
- activation following presentation of fearful stimuli.
state the three types of symptoms of anxiety.
emotional = fear cognitive = anxious thoughts somatic = increased heart rate
what parts of the brain does the amygdala activate?
coeruleus and hypothalamus.
describe the HPA axis.
H-hypothalamus releases CRH
P-pituatary releases ACTH
A-adernal cortex releases cortisol and adrenaline
what does lock coeruleus release?
noradrenaline.
name states of sympathetic nervous system.
- increased heart rate
- blood pressure
= prepares brain for situation e.g run faster away from threat
name states of the central nervous system.
- behavioural arrest and arousal
- cortisol activation
describe the role of the GABAergic system in regulating fear/anxiety.
evidence of GABA disfunction in anxiety disorders.
- panic disorder patients have less BZD binding sites.
- panic disorder patients lack sufficient inhibitory control in corticol and limbic regions to suppress inappropriate fear responses.
what occurs in the presence of BZDs as a drug?
- GABA molecules are more effective at opening CL- channel
- greater influx of chloride
- greater hyperpolarisation
- more inhibition
what type of structure do GABAa receptors have?
heteropentameric structure.
state drugs that increase GABAa receptor activity and so reduce anxiety.
- agonists = alcohol and barbiturates
- indirect agonist = BZDs