NT pathways:
-Mesocortical pathway: hypoactivity. Too little dopamine, causing the negative and cognitive symptoms. Causes receptors to be blocked. Increases dopamine in limbic circuits-hyperactivity- (positive symptoms, and descreases activity in PFC, which causes the increase cognitive and negative symptoms.
-Mesolimibic: hyperactive dopamine. Nucleus accumbus in feelings of rewards, too much labelling of inputs.
Tuberoinfundibular pathway – increases prolactine release. Side effect of antipsychotic.
Nigrostriatial pathway- movement disorders. “Pseudoparkinsonism”
Main medication: dopamine d2 antagonists, decrease of dopamine in the synaptic cleft. But in other areas of the brain you need an increase. Dopamine explains psychotic symptoms, not schizophrenia. Negative and cognitive symptoms respond poorly to antipsychotics.
Also: nowadays glutamate (more causal) -may be related to hallucinations, delusions, thought disorder and negative symptoms. Relapse in patients with schizophrenia. Negative symptoms, NMDA receptor hypofunction (currently being tested)
-Acetlycholine?- implicated in memory, attention & learning => cognition deficits