Brain Structure Flashcards
What are Venticles?
- Fluid filled cavities
- Contain spinal fluid
How would ventricles explain the cause of schizophrenia?
- They were bigger in patients who had schizophrenia
- Proved that other areas of the brain was smaller.
- Damaged in prefrontal and patients who have schizophrenia
Which brain areas are said to be a potential factor in causing schizophrenia?
- Prefrontal cortex
- emotional regions of the brain
Why does the onset of schizophrenia seem to be most common in adolescence?
- More physics and anatomical changes
- Chemical changes, changes in genes in side of the cell
Are there environmental factors that can affect the developing brain?
- Injuries sustained such as head injuries
- low weight and premature birth
CROW (1985)
- That those who do and dont have schizophrenia, can be related to the distinction of positive and negative symptoms
- POSITIVE SYMPTOMS - neutrotransmission
- NEGATIVE SYMPTOMS - brain structure
What does SMALL BRAINS and ENLARGED VENTRICLES suggest?
- The brain tissue being lost or certain areas have failed to develop fully such as frontal lobes, temporal lobes and hypothalamus
VENTRICLES
- Research using CAT scans has shown that approximately 25% of schizophrenic patients have enlarged ventricles in the brain. Ventricles are fluid-filled cavities that supply oxygen and blood to the densely packed neurons and remove waste products. Enlarged ventricles are usually caused by the death of brain tissue surrounding the ventricles and the fluid expanding to fill the space.
Post-mortem analysis of the brains
Post-mortem analysis of the brains of patients with schizophrenia have shown abnormalities with the most consistent issue being enlarged ventricles, which implies a loss
of brain cells. There is also some consistency with studies indicating structural problems in subcortical temporal limbic areas such as the hippocampus and the basal ganglia and in the prefrontal and temporal cortex.
- Brain scans have revealed even more compelling
findings of enlarged ventricles, especially in males.
GRAY MATTER
- Individuals with schizophrenia, including those who have never been treated, have a reduced volume of gray matter in the brain, especially in the temporal and frontal lobes.
- Patients with the worst brain tissue loss also tend to have the worst symptoms, which included hallucinations, delusions, bizarre and psychotic thoughts, hearing voices, and depression.
- Also, autopsies of deceased schizophrenics and CT scans indicate that schizophrenics have larger ventricles than
controls, so larger ventricles is an indication of tissue loss.
PREFRONTAL CORTEX
- prefrontal cortex is at the very front and top of the brain, and it helps people think logically and organize
their thoughts. - Further, brain imaging techniques
indicate that schizophrenics show a characteristic low
level of activity similar to those with frontal lobe damage, and in contrast to control groups, when performing this card sorting task Patients have
shown reduced metabolic rates in the prefrontal cortex when completing neuropsychological tasks during brain scans that place demands on the prefrontal
cortex. - This may be one reason that they suffer from delusions; after all, if they aren’t using
their prefrontal cortex as much as most people, they aren’t using the part of their brain that induces logical thinking. Some schizophrenics also suffer from disorganized thought
Patterns. - Since the prefrontal cortex also helps organize thoughts, less activity in that area
night be a cause of disordered thinking, as well as delusions.
BASAL GANGLIA
- The basal ganglia are located deep inside the brain, and it involves movement and thinking skills. Some studies have shown that patients with schizophrenia have larger basal
ganglia than normal people. This might affect the movement patterns of schizophrenics, who often have motor dysfunctions.
AMYGDALA
- The amygdala is the part of the brain that is responsible for basic feelings, like fear, lust and
hunger. - Patients with schizophrenia often have little emotion
- amygdala is smaller in people with schizophrenia.
The neurodevelopmental hypothesis states, various factors during the womb, the birth process, or after birth can cause brain lesions and these can make the individuals
affected vulnerable schizophrenics to viral infection/ malnurition
- It could be that a virus damages the brain during foetal development.
PREGNANCY
In 1957 in Helsinki
there was an epidemic of influenza virus and researchers examined the rates of schizophrenia amongst adults who were likely to have been exposed to this during
pregnancy.
- People exposed to the virus during the second trimester had much higher rates than those exposed in other stages or not exposed at all. Cortical development is in
a critical stage of growth during the second trimester.
