Dopaminergic neurotransmission Flashcards
(12 cards)
Describe the synthesis of dopamine
1) Tyrosin +MolcularO2+Fe+tertrahydrobiopterin —> DOPA +Dihydrobiopterin+H2O
Enzyme: tyrosine hydroxylase
2)DOPA +PLP —> Dopamine +CO2
Enzyme: DOPA decarboxylase
Describe the uptake of catecholamines by presynaptic terminals
Active transport 12 transmembrane segments Na co-transport sustrained depo. - cocaine and tricyclic antidepressants specific for individual transmitters but large homoogy between NA and DA transportes
Name 2 drugs that are involved in Parkinson disease treatment
L-DOPA
Deprenyl -> - MAO B
What are the structures involved in the reward system?
This are brain structures that regulate behavior by inducing pleasurable effects.
VTA-> nucleus accumbens -> frontal cortex
What blocks the uptake of dopamine in the synaptic vesicle?
Reserpine
Name a couple neurological processes that are initiated by dopamine.
(not in lecture)
Dopamine receptors are implicated in many neurological processes, including motivation, pleasure, cognition, memory, learning, and fine motor control, as well as modulation of neuroendocrine signaling.
How are catecholamines taken up by the presynaptic terminals?
- Active transport
- Na co-transport
- Sustained depol.
What are 2 inhibitors of the catecholamines taken up by presynaptic terminals?
Cocaine
tricyclic antidepressants
Which enzymes are there in the dopamine metabolism?
MAO
Aldehyde dehydro
COMT
Homovanillic acid
What is the level of homovanillic acid in Parkinson’s disease compared to Schizophrenia?
low in parkinson’s and high in schizophrenia
What is the function of Carbidopa?
It is an inhibitor of the conversion of L-DOPA -> DOPA in the periphery.
In this way the L-DOPA can travel through the BBB so that is can be converted there from L-DOPA -> DOPA. This improves the dopaminergic activity of the brain.
What are the traces/symptoms of Schizophrenia? Think of blood and levels of hormones etc.
+ dopamine level in the brain
+ homovanillic acid in the urine
+ D2 receptors
