Incedence + Pathology Flashcards
(45 cards)
What kind of illness is Schizophrenia
highly disabling psychiatric illness
What is the incidence in general population
1% incedence
What is the incidence in family history pop
6-17%
Incedence In twins?
50% if has affected twin
What does incidence indicate?
There is a genetic basis to Schizophrenia
Whats the difference in ventricles in schiz brain and why?
Larger ventricles in schiz brain as ventricular fluid fills up spaces in the brain that are made by neurodegeneration.
What are the differences in grey matter?
Reduced cortical grey matter in schiz
What are the post-mortem findings? + what do these indicate?
Cortical pyramidal cells have reduced dendritic length + reduced spine density in schiz brains.
More indication there is cortical degeneration happening.
What is schizophrenia?
A long-term psychiatric condition.
Characterized by significant impairment in reality perception and changes to behaviour.
When does schiz typically emerge?
In adolescence or young adult life.
4 genes associated with schizophrenia?
- Neuregulin
- Dysbindin
- DISC-1
- TCF4
What phenotype do transgenic mice that under-express neuregulin-1 show?
Phenotype resembling human schizophrenia.
3 environmental factors thought to increase risk of Schiz?
- Fetal development problems
- Prenatal exposure to viruses
- Stress during early life
Which 2 neurotransmitters primarily associated with imbalance in Schiz?
- Dopamine
- Glutamate
What structural brain changes observed in Schiz?
- Decreased grey matter volume
- Abnormal connectivity between brain regions
- Reduced dendritic length + spine density on pyramidal neurons
3 Categories of Schiz symptoms
- Positive symptoms
- Negative symptoms
- Cognitive symptoms
Describe the mesolimbic pathway
Transports dopamine from the ventral tegmental area (VTA) to nucleus accumbens, amgdala + hippocampus.
What is the role of the nucleus accumbens?
- Reward, desire and the placebo effect
- Central structure in mesolimbic pathway
- Involved in D2 hyperactivity + positive symptoms
- Involved in glutamatergic system
Describe the mesocortical pathway
Transports dopamine from ventral tegmental area (VTA) to prefrontal cortex.
What is the dopamine hypothesis of schiz?
Suggests overractivity of the dopamine system in brain is a key factor in development of schiz.
How does amphetamine support dopamine hypothesis?
Amphetamine releases dopamine in brain + can induce psychosis-like symptoms in patients.
How does L-DOPA + dopamine agonists support dopamine hypothesis?
- increasing dopamine via these agonists can worsen or induce psychotic symptoms
Proposed mechanism for positive symptoms in dopamine hypothesis:
Hyperactivity of dopamine D2 receptor neurotransmission in subcortical + limbic brain regions (mesolimbic pathway)
Proposed mechanism for negative symptoms in dopamine hypothesis:
Hypoactivity of dopamine transmission in mesocortical pathway.