Lecture 15 - Parkinson's

Question 1

What are the 2 most important dopamine pathways in the brain?

Answer 1

-nigrostriatal dopamine pathway
-mesocorticolimbic dopamine pathway

Question 2

What does the nigrostriatal dopamine pathway consist of?

Answer 2

-it starts in the substantia nigra [SN] and projects to the dorsal striatum [DS] (a.k.a the caudate-putamen)

Question 3

What does the mesocorticolimbic dopamine pathway consist of?

Answer 3

-it starts in the ventral tegmental area (VTA) and projects to the ventral striatum [VS] (a.k.a the nucleus accumbens) and the prefrontal cortex

Question 4

What is the nigrostriatal primarily responsible for?

Answer 4

-initiation of movement
-habit learning
-coordination of smooth movement

Question 5

What are some symptoms of Parkinson’s?

Answer 5

-difficulty initiating movement
-resting tremor
-speech difficulties
-slowness of movements

Question 6

What’s another symptom present in later stages of Parkinson’s?

Answer 6

-learning and memory deficits
-suggesting that the nigrostriatal dopamine pathway may also play a role in learning

Question 7

What is the cause of Parkinson’s?

Answer 7

-the cause is unknown, but it’s believed to be a combination of genetic and environmental factors.
-evidence suggests that environmental factors [exposure to industrial chemicals or pesticides] may play a role

Question 8

When do the symptoms of Parkinson’s disease usually appear?

Answer 8

-they do not usually appear until a significant number of dopamine neurons in the SN have died.
-because the brain has a compensatory mechanism that allows the remaining DA neurons to sprout and make more connections.
-but when the compensatory mechanism is overwhelmed, the symptoms begin to emerge

Question 9

What is the cure for Parkinson’s?

Answer 9

-there is no cure for Parkinson’s disease, but there are treatments that can help to manage the symptoms

Question 10

What is the first line of treatment?

Answer 10

-physiotherapy
-can help patients to learn to compensate for their movement disorders

Question 11

What is the most common medication used to treat Parkison’s?

Answer 11

-L-dopa (can cross BBB)
-L-dopa helps to replenish DA levels in the DS and can improve symptoms

Question 12

What is another treatment [other than L-DOPA] that can be used?

Answer 12

-deep brain stimulation
-involves implanting electrodes in the brain that stimulate the DA neurons in the SN to fire more frequently.
-it is a more invasive procedure than medication.

Question 13

What are the side effects of Parkinson’s treatments?

Answer 13

-slight personality change (disturbing behaviours)
-increased sexual behaviours
-increased gambling