Parkinson's Disease Flashcards
What is the term for a disease which has no single cause and occurs randomly?
Idiopathic and sporadic
What are the symptoms?
involuntary shaking of particular parts of the body (tremor) stiff and inflexible muscles Bradykinesia- slow movement mask like expression posture
How is dopamine linked to PD
Too little dopamine in the substantia nigra leads to a lack of input in the basal ganglia which causes the globus padillus to be stuck “on” which means that there is excessive output.
What is the frozen addict
MPTP was an unwanted by product of synthetic heroin, MAO converted it into MPP which is very dangerous and targeted the dopamine cells of the substantia nigra pars compacta.
ANimal models
monkeys treated with MPTP had significant changes in their indirect pathway.
What do micro- electrode studies show?
Micro- electrode studies show that a decrease in the tonic activity of the external pallidal segment
But an increase in internal segment and subthalamic nucleus.
the indirect pathway…
increased activity
the direct pathway…
decreased activity
Treating parkinson’s with drugs
L- DOPA (dopamine precursor)
Apomorphine (Da agonist)
Deprenyl (monoamine da and 5HTT agonist)
Cannabis
Treating with surgery
LEsion the inhibitory output structure
electrical stimulation of the basal ganglia - deep brain stimulation.
replacing lost cells
stem cells
FLOW CHART
Loss of nerve cells in substantia nigra (midbrain)
Projects to the basal ganglia
The loss of the dopaminergic input causes the globus padillus internal segment to be switched on= excessive output.
