Neurobiology Flashcards
What is the function of the appetitive system?
mediate seeking and approach behaviours (including pleasure) –> reward system
Which neurotransmitter is involved in the appetitive system?
dopamine
What is the function of the aversive system?
to promote survival in event of threat (fear/pain)
Which neurotransmitter is involved in the aversive system?
serotonin
What is the effect of decreased noradrenaline transmission?
anergia, anhedonia, decreased libido
What is the effect of antidepressants on GABA receptors?
unregulated GABA receptors
Which neurotransmitters are hypothesised to be deficient in depression?
serotonin
NA
dopamine
GABA
Which neurotransmitters are hypothesised to be in excess in depression?
acetylcholine
substance P
corticotrophin releasing hormone (CRH - stress hormone)
Describe the HPA axis in mood disorders.
CRF is hyper-secreted from hypothalamus so ACTH released from pituitary
ACTH causes adrenal glands to release cortisol
negative feedback of cortisol to hypothalamus, pituitary & immune system is impaired –> continual activation of HPA axis and excess cortisol release
cortisol receptors become desensitised -> increased activity of pro-inflammatory immune mediators & disturbed neurotransmitter transmission
Which negative experience can result in over-active response of noradrenaline system?
adverse childhood experience > over-active responsiveness of NA system that persists into adulthood.
In which situation would some people deplete NA but not others?
in situations that most people don’t find too stressful, those who are vulnerable and depressed may feel very stressed and deplete NA
depletion of NA -> depression in recovered patients but not unaffected people
