Flashcards in 5) Neurotransmitters Deck (21)
Describe the features of a neuron:
Dendrites at receiving end
Soma (cell body)
Axon +/- myelin sheath
What are the two main neurotransmitters involved in depressive disorders?
What other neurotransmitter are involved in psychiatric conditions?
What are the functions of noradrenaline in the brain?
Role in behaviour (arousal and attention)
Implicated in memory functions
Where is noradrenaline made in the brainstem?
What role do alpha receptors play in the brain?
Arousal and mood
What enzymes break down noradrenaline?
Describe the synthesis of noradrenaline:
Tyrosine -> DOPA -> Dopamine -> noradrenaline (-> adrenaline)
What evidence is there for noradrenaline being implicated in depression?
AMPT inhibits formation of NA and cause depressive symptoms
Antidepressants block reuptake of NA
Reserpine depletes nerve ends of NA (causes depressive symptoms)
What is the role of serotonin in the brain?
Where in the brainstem is serotonin produced?
What is serotonin synthesised from?
What can serotonin go on to form?
Melatonin (control of sleep)
What evidence is there for serotonin being implicated in depression?
Metabolite of serotonin in CSF is depleted in depression
Tryptophan depletion causes depression
PET and SPET studies
What disorders are changes to dopamine associated with?
What effect does dopamine have?
Feelings of pleasure
What evidence is there for dopamine being implicated in depression?
HVA (metabolite of dopamine) low in depressed
ECT affects dopamine system
40% of those with Parkinson's have depression
Describe some neurotransmitter changes in mania:
Dopamine agonists cause manic symptoms
How does lithium act as a mood stabiliser?
Positive effect on BDNF transcription
Positive effect on serotonin production
How do GABAa receptors cause an effect?
Chloride ion channels (inhibitory)