Dopamine Mechanism

Question 1

What are the 4 key pathways affected by dopamine in the brain?

Answer 1

• Mesocortical
• Mesolimbic
• Nigrostriatal
• Tuberoinfundibular

Question 2

Describe the mesocortical pathway

Answer 2

• Projects from ventral tegmentum (brainstem) to cortex
• Where the negative symptoms come from
• Too little dopamine

Question 3

Describe the mesolimbic pathway

Answer 3

• Projects from ventral tegmentum (brainstem) to limbic system
• Where the positive symptoms come from
• Too much dopamine

Question 4

Describe the nigrostriatal pathway

Answer 4

• Projects from dopaminergic cell bodies in the substantia nigra to the basal ganglia
• Suppresses acutely choline activity
• Can cause Parkinsonian movements

Question 5

Describe the tuberoinfundibular pathway

Answer 5

• Projects from hypothalamus to anterior pituitary
• Blocking dopamine in this pathway will predispose the patient to hyperprolactinaemia (decreased libido, menstrual dysfunction etc.)

Question 6

What is olanzipine?

Answer 6

Atypical antipsychotic

Question 7

What are the side effects of olanzipine?

Answer 7

• Weight gain
• High fats and sugar
• Hyperprolactinaemia
• May cause abnormal LFTs