dopamine hypothesis

what does this image show?

neuron

what does this image show?

synaptic transmission

what is the role of dopamine in schizophrenia? how was this discovered?

research in the 1950s- people were given L-dopa which increased the amount of dopamine in the brain. when given it, they displayed behaviours similar to that of schizophrenia, suggesting that increased dopamine leads to positive symptoms of schizophrenia

what is the initial dopamine hypothesis?

individuals with sz had too much dopamine and symptoms related to high levels of it. they discovered several subtypes of dopamine receptor- d1 to d5. these are widely distributed in the cerebral cortex and the limbic system

in the revised dopamine hypothesis- what is the role of the mesolimbic pathway?

carries signals from VTA to NA. too much dopamine is produced from neurons firing too quickly or too often, causing overstimulation. this causes positive symptoms including hallucinations and delusions

in the revised dopamine hypothesis- what is the role of the mesocortical pathway?

carries signals from VTA to frontal lobe. vital pathway in emotional responses, motivation and cognition. too little dopamine in D1 receptors of frontal lobe cause cognitive impairments and negative symptoms

Give a piece of supporting evidence for the dopamine hypothesis.

Griffith et al- induced psychosis in non schizophrenic people by giving them dextro-amphetamine. induced paranoid delusions and cold and detached response. suggests that increased dopamine causes an onset of positive symptoms