Case 8 Summary - ILOs

Case 8 Summary
General ILOs:

- To demonstrate knowledge of the elevated presynaptic dopamine function in the
nigrostriatal pathway associated with psychotic symptoms in schizophrenia
- To demonstrate knowledge of the potential risks associated with schizophrenic
symptoms
- To demonstrate knowledge of the reduced dopamine function in prefrontal
cortex associated with cognitive symptoms in schizophrenia
- To demonstrate knowledge of the reduced dopamine function in prefrontal
cortex associated with cognitive symptoms in schizophrenia
- To demonstrate understanding of the nature of delusions and auditory
hallucinations (i.e. positive or psychotic symptoms) in schizophrenia

Dopamine receptors exist within two major families:

 D1 – activate adenylyl cyclase
 D2 – inhibit adenylyl cyclase

The dopamine system has four major projections:

 Nigrostriatal pathway
o Part of the basal ganglia
o Projects to striatum
o Facilitate movement
 Mesolimbic pathway
o Rewards pathway
o Begins in the ventral tegmental area (VTA)
o Nucleus accumbens is involved in motivation
 Mesocortical pathway
o Originates in VTA
o Travels to frontal lobes
o Reward pathway
 Tuberoinfundibular pathway
o Consists of hypothalamus and infundibular region
o Inhibit prolactin release




1
Guillaume Antem – MBChB Y2

, In schizophrenia, there are two abnormalities associated with the dopamine pathways:

 Excessive dopamine release in the associative striatum
o Relates to the positive symptoms
o Correlates with good response to antipsychotics
o AKA mesolimbic pathway
 Inadequate dopamine release in the prefrontal cortex and ventral striatum
o In DLPFC – cognitive impairment
o In VST – negative symptoms
o AKA mesocortical pathway

In addition to inappropriate dopamine release, glutamate receptor hypofunction (specifically
NMDA receptor) is present in schizophrenia.




2
Guillaume Antem – MBChB Y2