Limbic System II Flashcards
What causes Urbach-Wiethe disease?
Bilateral Amygdala lesions
What symptoms are associated with Urbach-Wiethe disease?
[Bilateral amygdala lesions]
- Impaired recognition of emotion (in facial expression)
- –Inability to judege “like” emotions (ex: fear vs. anger, surprise vs. happy)
- Memory loss especially of information with emotional content
What are the symptoms of PTSD?
- Re-experiencing phenomena (flashbacks)
- Avoidance (of situations similar to original trauma)
- Hyperarousal (hypervigilance - high anxiety)
What is the etiology of PTSD?
- Inc. amygdala activity (in fMRI)!
- Dec. medial prefrontal cortex activity
What does the medial prefrontal cortex do to the amygdala in PTSD?
It plays a role in inhibiting the amygdala in PTSD.
What does imaging show in Parkinson’s?
Dec. in neurons in the substantial nigra
What are the core features of schizophrenia?
Fragmentation of mood, thought and movement.
What are positive and negative symptoms of Schizophrenia?
Positive - delusions, hallucinations
Negative - social withdrawal
What is the incidence of schizophrenia?
1% of US population
What is happening on a neurochemical basis in schizophrenia? What is the “dopamine hypothesis”?
Dopamine hypothesis - schizophrenia caused by Inc. DA receptor activity.
What does haloperidol do?
It is an anti-psychotic used for schizophrenic patients. It blocks dopamine receptors
What are the side effects of anti-psychotic haloperidol?
It causes motor dysfunction (parkinsonian-like) and is not effective in some people.
What is clozapine?
It is an atypical anti-psychotic used to treat schizophrenia.
What is clozapine’s mechanism?
- It blocks DA recpetor: rapid off rate
- Blocks 5HT receptors
- Blocks glutamate reuptake (increases glutamate in synapse)
What is the “glutamate hypothesis”?
-Schizophrenia somehow causes a block in NMDA glutamate receptor
What is Phencyclidine (PCP)?
“Angel dust” - blocks NMDA glutamate receptor