Biological Explanations-neural Flashcards
Role of dopamine
Neurotransmitter that has anxiety affect leaked to sensation of pleasure.
Unusually high levels associated with SZ , unusually low levels associated with Parkinson’s disease
Neural correlates of SZ
We don’t know what causes symptoms
Research found some neural correlates (brain structure or function )
dopamine is the best known neural correlate -important for functioning of several brain systems related to Sz
The original dopamine hypothesis
Focuses on higher levels of dopamine in the subcortex
Antipsychotics caused Parkinson like symptoms
Parkinson = low dopamine levels, Sz= high dopamine levels
Excessive dopamine receptors in brokers area may explain speech poverty or auditory hallucinations
Increasing dopaminergenic activity
Amphetamine is a dopamine antagonist-stimulates nerve cells containing dopamine
Synapse flood with dopamine. People who take them suffer schizophrenogenic symptoms
When they stop taking the symptoms disappear
Decreasing doperminergic activity
Antipsychotic drugs blocked dopamine activity
Reduce activity in dopamine pathways
Eliminates positive symptoms
Updated version of the dopamine hypothesis
Davies et al-cortical hypodopaminergia- low dopamine in brain cortex- Sz
Low dopamine in prefrontal cortex (thinking) could explain negative symptoms
cortical hypodopaminergia could lead to subcortical hyperdopaminergia
Updated versions try to explain the orange end of abnormal DA function
Exposure to stress make people more sensitive to hyper and hypo .
Strength-evidence for dopamine
Curran-amphetamines inc DA which worsen SZ symptoms and induces in those without it
Tauscher-antipsychotics reduced dopamine activity and the intensity of symptoms
Some candidate jeans act on the production of dopamine
Limitations-glutamate
Post-mortem and scanning show evidence of high levels of transmitter glutamate
Evident in lots of brain regions in those with SZ
Several candidate are involved in glutamate production -other neurotransmitters may be involved
