Flashcards in Neurobiology of psychosis Deck (19):
What are the following associated with? :
-reduced frontal lobe volume
-reduced frontal lobe grey matter
-enlarged lateral ventricle volume
Associated with a poor prognosis
Schizophrenia is associated in changes of which matter in the brain?
Associated with changes in the grey matter
-changes are widely distributed
-changes are present early in the disease (and likely premorbidly)
-Grey matter reductions due to reduced aborisation and not neuron loss
-grey matter reductions likely PROGRESSIVE in the initial years of the illness
Good way to image the drug?
Diffusion tensor imaging (DTI)
What does fractional anisotropy mean? (in terms of diffusion tensor imaging)
Higher numbers mean healthy white matter tracts
(but higher FA correlates with psychotic symptom severity. Myelin abnormalities may be a cause of the anisotropy abnormalities)
What does mean diffusivity mean? (in terms of diffusion tensor imaging)
Higher numbers mean LESS healthy white matter tracts
Why is it not possible to diagnose schizophrenia by radiology?
Not possible because of abnormal variation i.e. the AVERAGE brain of a patient with schizophrenia is smaller than the AVERAGE brain in a healthy control (average etc blah blah)
Factors in pregnancy which could lead to schizophrenia development of that baby?
-2nd trimester viral illness
-Obstetric problems: pre-eclampsia. fetal hypoxia, emergency caesarian section
Dopamine and the brain
It is assumed that schizophrenia is related to overactivity of dopamine pathways
How does amphetamine act on the dopamine pathway?
Amphetamine releases dopamine in the brain
What does the D1 receptor family stimulate? (D1 and D5)
What does the D2 receptor family do? (D2, D3, D4)
-Inhibit adenyl cyclase
-Inhibit voltage-activated Ca2+ channels
-Open k+ channels
(D2 agonists produce psychotic symptoms in ppl)
Where would you find D1 and D2 receptors in the brain?
Limbic and striatal areas
What is clozapine?
What is neuregulin?
A signalling protein that mediates cell-cell interactions
-plays CRITICAL ROLE IN THE GROWTH AND DEVELOPMENT of multiple organ systems
What is Dysbindin essential for?
Essential for adaptive neural plasticity