Psychosis - Neurobiology Flashcards
What are some features which may be seen in patients with schizophrenia who have a poor prognosis on imaging?
Reduced frontal lobe volume, enlarged lateral ventricles, reduced grey matter
Reduced grey matter may be seen in what specific areas in patients with schizophrenia who have a poor prognosis on imaging?
Frontal lobe, temporal cortex and medial temporal lobe
When do the grey matter changes in schizophrenia tend to occur?
Early in illness, most likely pre-morbid
Are grey matter changes in schizophrenia progressive?
Yes, especially in the initial years of illness
Children who later develop schizophrenia often have identifiable abnormalities in what from infancy?
Impaired behavioural, motor and intellectual development
Apart from grey matter changes, what is another key feature of brain change in schizophrenia that is present at diagnosis? Is this progressive?
Ventricular enlargement - not progressive
Is gliosis seen in the brain in schizophrenia?
No
What is the most widely accepted hypothesis for the cause of schizophrenia?
Dopamine excess
Dopamine excess only explains what type of symptoms of psychosis?
Positive symptoms
What type of drugs are usually used to treat the symptoms of psychosis?
Dopamine receptor antagonists
What subtypes of dopamine are seen within the D1 receptor family? What is their function?
D1 and D5 - stimulate cAMP
What subtypes of dopamine are seen within the D2 receptor family? What is their function?
D2-D4 - inhibit adenyl cyclase, inhibit Ca++ channels and open K+ channels
Which dopamine receptor family is pharmacologically more important?
D2
Which dopamine receptor family is more abundant in the CNS?
D1
Both D1 and D2 receptor families are found where? D2 is also seen where?
Limbic and striatal areas of the brain / pituitary gland
