5) Neurotransmitters Flashcards
Describe the features of a neuron:
Dendrites at receiving end
Soma (cell body)
Axon +/- myelin sheath
Terminal buttons
What are the two main neurotransmitters involved in depressive disorders?
Noradrenaline
Serotonin
What other neurotransmitter are involved in psychiatric conditions?
Dopamine
GABA
ACh
Glutamate
What are the functions of noradrenaline in the brain?
Mood
Role in behaviour (arousal and attention)
Implicated in memory functions
Where is noradrenaline made in the brainstem?
Locus coeruleus
What role do alpha receptors play in the brain?
Arousal and mood
What enzymes break down noradrenaline?
Monoamine oxidase
COMT
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?
Sleep
Impulse control
Appetite
Mood
Where in the brainstem is serotonin produced?
Raphe nuclei
What is serotonin synthesised from?
Tryptophan
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
Antidepressants (SSRIs)
What disorders are changes to dopamine associated with?
Parkinson’s disease
Schizophrenia
