22.2 Pharm: Dopamine

Question 1

What is dopamine’s role in the CNS?

Answer 1

Dopamine: tonic inhibition

ACh is the excitatory input

Question 2

What do we use to treat Parkinson’s disease?

Answer 2

L-DOPA (dopamine can’t cross the BBB)

Question 3

How does Parkinson’s disease occur?

Answer 3

Dopaminergic nerves in the substantia nigra degenerate

Question 4

What are some symptoms (incl. the first) that we see in Parkinson’s?

Answer 4

Loss of sense of smell (first)
Tremor/rigidity
Depresson

Question 5

What is the hypothesis as to why some people get Parkinson’s?

Answer 5

A mitochondrial mutation=inability to process ROS

Question 6

What breaks down dopamine after neuronal uptake?

Answer 6

Monoamine oxidase MAO

Question 7

What are some of the issues with using Levodopa (L-DOPA)?

Answer 7

Short half life
Decreased effectiveness with time
Pathology acceleration (patients decline faster)

Question 8

What is L-DOPA formulated with? Why?

Answer 8

DCC inhibitor (Dopa decarboxylase)
-Because 90% of L-DOPA is metabolised in the periphery

Question 9

What alternative is there instead of L-DOPA?

What is a pro and a con?

Answer 9

Dopamine agonists

Pro: no acceleration of pathology

Con: non specific/off target effects (entire brain gets it)

Question 10

What can we use to restore the dopamoinergic-cholinergic imbalance? (adjunct with L-DOPA)

Answer 10

Muscarinic receptor antagonists

Question 11

Describe the extrapyramidal motor system:

Answer 11

Mention:
ACh (excitatory), Dopamine

Corpus striatum, substantia nigra

GABA

Corpus striatum–> Cortex–>spinal cord–>output to skeletal muscle