Neurodegeneration 3 second half 2.0 Flashcards
Effect of dopamine on the facilitatory pathway between the striatum and the motor cortex?
It enhances it
Effect of dopamine on inhibitory pathway between the striatum and the motor cortex?
It inhibits it
Which dopamine receptor is targeted by dopamine for the facilitatory pathway?
D1
Which dopamine receptor is targeted by dopamine for the inhibitory pathway?
D2
Effect of dopamine loss in PD?
Reduced motor cortex activity
How can dopamine be increased?
Provide more dopamine or more dopamine precursor, decrease its reuptake, inhibit its breakdown, provide a dopamine agonist
Most common parkinsons treatment?
Provide L-Dopa
Why is L-Dopa provided instead of dopamine?
L-Dopa can cross the blood brain barrier
Technical issue with L-Dopa?
It can be converted to dopamine (which cant cross BBB) in the blood
Which drug is given alongside L-Dopa to prevent dopamine formation in the blood?
Cabidopa (dopa decarbodylase inhibitor)
Side effect of L-Dopa?
Dyskinesia–> severe involuntary movement
How is the dyskinesia of L-Dopa treatment managed?
Patients have an “off” time where they dont take any L-Dopa in order to reduce the prevalence of side effects
Second treatment aim at PD after L-Dopa?
Inhibit breakdown of dopamine
How is dopamine breakdown inhibited?
Monoamime oxidase B (MAOB) inhibitors
What is the main MAOB inhibitor?
Selegeline
PD treatment after L-Dopa and MAOB inhibitor?
Catechol O-Methyl Transferase (COMT) inhibitor
Side effects of L-Dopa?
Nausea and dizziness
Side effects of COMT?
Toxicity to liver cells, diarrhoea and sleep disturbances
Main COMT used for PD?
Tolcapone
How do dopamine agonists work?
Acts directly on dopamine receptors
Side effects of dopamine agonists?
Nausea, dizziness, hallucinations, sleep attacks, hypotension
Examples of dopamine agonists?
Pramipexole, Ropinirole, Bromocriptine
What is deep brain stimulation?
Implanting an electrode into the striatum–> can stimulate it directly and thus stimulate the activity
Benefits of deep brain stimulation?
Doesnt have the same side effects of L-Dopa
Complications of deep brain stimulation?
Brain hemorrhage, seizures, death
Issues with stem cell treatment for ND?
Cost and time
