carlsonn et al Flashcards
what was the methodology
paper review of research findings
where did carlsonn obtain evidence from
- carlsonns own work
- work of others
- animal research
- PET scans
- Parkinsons and Huntingdons disease
what is glutamate
- most common neurotransmitter accounting for 90% of synaptic conditions
- involved in learning and memory
- regulates development and creation of nerve contacts
- glutamate bond to NMDA receptors
what is dopamine
- controls the brain reward and pleasure centres
- feelings of pleasure, addiction, movement and motivation
- people repeat behaviours that lead to dopamine production
what is the glutamate hypothesis
- glutamate is a neurotransmitter
- stimulates a group of receptors
- recreational drug PCP - act like they have schizophrenia
- acts at one of the receptors that glutamate stimulates and blocks the receptors
- have a defect in the receptor so cannot be stimulated by glutamate
what did professor daniel Weinberger find
- evidence has increasingly centred around areas of the brain like the frontal lobe
- the main neurotransmitters are amino acid neurotransmitters like glutamate and GABA
- glutamate is the principle neurotransmitter of cells that communicate across long distances in the brain
- critical for function of the cortex
- PCP –> causes distraction and change in the ability to pay attention
what was the aim of the study
to produce drugs that reduce levels of relapse and negative side effects
- hyperdominergia –> high levels of dopamine
- hypoglutamatergia –> low levels of glutamate
low levels of glutamate is associated with high dopamine levels
- dopamine hypothesis has been strengthened with improvement in tech showing more complex neural interactions with dopamine and other neurotransmitters
what is the rationale
- there is no ‘one cause’ for SZ
- it neurotransmitter functioning causes SZ symptoms then drug treatments can help
- antipsychotic drugs work to suppress hallucinations and delusions
- there are now likely safer antipsychotic medications but they have failed to become more effective overall
what were the agreed findings
- PCP –> acts as an antagonist of a glutamate receptor, glutamate deficiency more likely to be result in psychosis
- glutamate failure –> in the cerebral cortex may lead to negative symptoms, in the basal ganglia may lead to + symptoms
- clozapine is a highly effective drug for SZ –> fewer reported side effects, reduces levels of dopamine and serotonin, more effective in patients who have not previously responded to treatment
what animal studies did they conduct
- research done on mice in early 2009 has shown that administering NMDA antagonists in late/post foetal stage increases neuronal death which is linked to adult schizophrenia like behaviour
- this led to symptoms that overlap with sz
conclusions
- further research is needed in developing drugs to treat SZ. to avoid negative side effects, consider the role of other neurotransmitters
- different types of SZ could be due to abnormal levels of different neurotransmitters
aim
to review research on the effects of the neurotransmitters dopamine and glutamate on the symptoms of SZ
procedure
the researcher looked at number of different studies to assess whether high levels of dopamine and low levels of glutamate are linked to SZ
results
there is evidence to support the hyperdopaminergia and hypoglutamatergia models of SZ. clozapine which blocks the activity of dopamine and serotonin has been found to be a more effective treatment for schizophrenia than drugs that block the activity of dopamine alone. this may be because levels of serotonin have an effect on levels of glutamate
evaluation
- the review looked at a number of different studies, the use of many studies makes the findings more generalisable to the wider population
- not all studies used in the review may have been equally reliable. however studies used in the review were scientific such as PET scans and this makes the review more reliable
- the review suggests that new drugs that act on different neurotransmitters should be developed for sz
- not all studies used in the review may have been equally valid, which could distort the overall findings. however, using evidence from a large number of studies can give more valid conclusions about the effect of different neurotransmitters on the symptoms of sz
- as secondary data was used, there are no ethical issues with this study
