Schizophrenia- biological dopamine

Question 1

What is the initial dopamine hypothesis?

Answer 1

The brain of a SZ patient produces more dopaine than normal brains this is called HyperDopaminergia
Increased dopamine believed to be responsible for some symptoms of disorders

Question 2

Dopamine and Broca’s area?

Answer 2

An area of the brain responsible for speech production may be associated with speech poverty and or the experience of auditory hallucination

Question 3

Initial Dopamine research- Fallaki et al?

Answer 3

Autopsy have found people with SZ have a larger than usual of dopamine receptors
Concluding dopamine production is abnormal for SZ compared to normal controls

Question 4

Why is the initial dopamine hypothesis to simplistic?

Answer 4

They helped treat positive symptoms but not negative
Complicated by the discovery of subtypes of dopamine receptor sites D1-D5 which were spread in both cortical (cerebral cortex) and subcortical (limbic system) areas of the brain

Question 5

What is the revised dopamine hypothesis?

Answer 5

Focuses on the limbic system
-There are 2 main nerve pathways, associated with SZ that leave the limbic system to other subcortical structures and the cerebral cortex
-Mesolimbic pathway
-Mesocortical pathway

Question 6

What is the mesolimbic pathway responsible for?

Answer 6

Positive symptoms

Question 7

What is the mesocortical pathway responsible for?

Answer 7

Negative symptoms

Question 8

What is the mesolimbic pathway?

Answer 8

In SZ there’s to much dopamine from neurons that fire to often or to quickly causing overstimulation causing positive symptoms or SZ such as hallucinations or delusions

Question 9

How do antipsychotics work in the mesolimbic pathway?

Answer 9

Antipsychotics work to reduce dopaminergic neurotransmitters and reduce dopamine activity in the pathway and reduce the positive symptoms of people with SZ

Question 10

What is the mesocortical pathway?

Answer 10

Hypo dopaminergia to little dopamine
Dopamine is a major neurotransmitter in pathway
It carries signals from the VTA to the frontal lobe and it vital in emotional responses

Question 11

Mesocortical pathway- Kenneth Davis et al 1991?

Answer 11

To little dopamine is evident in D1 receptors in the frontal lobe of many individuals with the cognitive impairment of negative symptoms in SZ