Dopamine Pathways

Question 1

What is the route of the Nigrostriatal pathway?

Answer 1

Substantia nigra to striatum and amygdala via medial forebrain bundle

Question 2

What is the role of the Nigrostriatal pathway in disease?

Answer 2

DA deficiency (e.g. Parkinson’s) can cause extrapyramidal side effects

Question 3

What are the four main extrapyramidal side effect groups?

Answer 3

1. Dystonia - acute rigidity and muscle spasm
2. Parkinsonism - bradykinesia, tremor, shuffling gait, rigidity
3. Akathisia - shuffling, restlessness, inability to stay still (not anxiety)
4. Dyskinesia (tardive) - grimacing, strange mouth and tongue movements, slurred speech

Question 4

What is the route of the Mesolimbic pathway?

Answer 4

Ventral tegmental area to nucleus accumbens and hippocampus via medial forebrain bundle

Question 5

What is the therapeutic role of the Mesolimbic pathway?

Answer 5

Dopamine blockade produces desirable antipsychotic effects, controls positive symptoms

Question 6

What is the route of the Mesocortical pathway?

Answer 6

Ventral tegmental area to cingulate cortex and prefrontal regions via the medial forebrain bundle

Question 7

What is the role of the Mesocortical pathway in disease?

Answer 7

DA blockade causes negative symptoms (e.g. alogia, anhedonia, apathy)

Question 8

What is the route of the Tuberoinfundibular pathway?

Answer 8

Hypothalamus to the pituitary via the portal vessels

Question 9

What is the role of the Tuberoinfundibular pathway in disease?

Answer 9

DA blockade increases prolactin levels as DA acts as prolactin inhibitory hormone