Neurobiology Flashcards
what is the function of the appetitive system
reward system
what is the main neurotransmitter in the appetitive system
dopamine
what is the function of the aversive system
survival in event of threat - fear/pain
what is the main neurotransmitter in the aversive system
serotonin
depression is an altered sensitivity of the brain systems evaluating _______ - the ____ system
rewards - appetitive system
anxiety is an altered sensitivity of the brain systems evaluating ____ - the ____ system
threat - aversive system
what neurotransmitters are in excess in depression and what are deficient
deficient - serotonin, dopamine, NA, GABA, BDNF, somatostatin
excess - ACh, Substance P, CRH
what axis is upregulated in depression
HPA
cortisol is reduced/raised in depression
raised
what is the main serotonin receptor involved in depression
5HT1A
adverse childhood experiences can cause an over active responsiveness in the NA system - situation that isnt too stressful depletes NA which causes
depression
what is the underlying mechanism in anhedonia in depression
hypofunction of dopamine system
what is a drug that can deplete stores of monoamines and induce low mood
reserpine
of the following monoamines which are excitatory and which are inhibitory
- dopamine
- NA
- serotonin
dopamine - excitatory
NA - excitatory
serotonin - inhibitory
what is heritability
the degree of variability in a trait that is caused by genetic differences in a population i.e. how much contribution there is from genetics in the average individual with the disorder
patients with schizophrenia have _______ reductions
grey matter volumetric reductions
where are consistent reductions in grey matter volume seen
temporal cortex - especially superior temporal gyrus
medial temporal lobe - particularly hippocampus
GM reductions is due to what
reduced arborisation not loss of neurones
is it possible to diagnose schizoprenia from brain imaging
no
what happens to the brain to compensate for space left by atrophied brain
ventricular enlargement
what drugs produce a psychotic state
drugs which release dopamine in the brain e.g. amphetamine or D2 receptor agonists e.g. apomorphine
what drugs are used to treat symptoms of schizophrenia
dopamine receptor antagonists - metoclopramide, prochlorperazine, droperidol, promethazine
schizophrenia is related to over activity of ____ in the brain
dopamine pathways
what are the 2 dopamine receptor families
D1 family - D1 and D5 - most abundant
D2 family - D2 D3 D4
__ receptor family stimulates cAMP
__ receptor family inhibits adenylyl cyclase
D1 stimulates cAMP
D2 inhibits adenylyl cyclase
bromocriptine is a ___ receptor agonist
D2
subcortical dopamine ______ leads to psychosis
mesocortical dopamine ______ leads to negative symptoms
hyperactivity
hypoactivity
what are 3 genes that cause brain pathology
neuregulin
dysbindin
DISC-1
what are the bodies 2 responses to fear
freeze
flee
when does the body freeze
inescapable or distant threat
when does the body flee
nearby threat and escapable
reactions to fear arise in the ___ or ___
PAG
ventral tegmental area
what is tonic immobility
involuntary state of profound but reversible motor inhibition - occurs especially if in direct contact with the predator
as predator closes in, brain activity switches from ___ to _____
ventromedial prefrontal cortex to PAG
where is the PAG
midbrain
when under threat there is a shift from ____ to _____ activation
cortical to subcortical
what are the 3 looping systems in defence activation
midbrain/brainstem origin - PAG and Superior colliculi
mesolimbic - dopamine system
stimulus response learning system
what increases when PAG inputs are fear/rage/panic/grief
increase in dysmorphins and CRF
what increases when PAG inputs are care/nurturing/sexual desire
oxytocin, prolactin, u-opioids
acute stress leads to dose dependent increase in
catecholamines and cortisol
cortisol levels are ____ in acute stress
increased
cortisol levels are ___ in PTSD
decreased
pre peri and post traumatic resilience factors are related to what
pre - person
peri - trauma
post - environment
processing in the brain is lead either by
mamillian brain or reptillian brain
mamillian brain has _____ processing
reptilian brain has ____ processing
mamillian - top down
reptilian - bottom up
mamillian brain speaks language of _____
reptilian brain speaks language of _____
emotion - mamillian
impulse - reptilian
