CNS pharmacology III Flashcards
How were anti-psychotic drugs discovered?
What did this give rise to?
Found to be effective by chance
Gave rise to the understanding of the disease through research into WHY the drug was effective
What neurotransmitter system is effected in Schizophrenia?
The dopaminergic pathway
What causes the symptoms associated with positive Schizophrenia?
INCREASE levels of dopamine signalling
What can the symptoms of Schizophrenia be broken down into?
2 groups:
1) NEGATIVE
2) POSITIVE
What are the negative symptoms of Schizophrenia?
NEGATIVE state of mind:
- Blunting of emotions
- Withdrawal from social contacts
- Flattening of emotional responses
- Reluctance
- Anhedonia (no pleasure from pleasurable activity)
What are the positive symptoms of Schizophrenia?
- Hallucinations
- Delusions (paranoia)
- Thought disorders
- Agression
- Bizarre behaviour
What CAN symptoms of Schizophrenia be accompanies by?
May/may not be accompanied by:
- Cognitive defects
- Anxiety
- Depression
- Self-punishment
Are there differences between the brains of normal and Schizophrenia brain?
Yes
What are the causes of Schizophrenia?
- Hereditary elements
- Disruption in the normal neuronal development
- Genes turned off that are associated with the formation of synapses and synaptic activity
- Heavy cannabis use
Who normally has symptoms of negative Schizophrenia?
Elderly
Who normally has symptoms of positive Schizophrenia?
The young
Once somebody has Schizophrenia, what can and can’t be treated?
Can treat the SYMPTOMS
But not the CAUSE - when have Schizophrenia, cannot be reversed
How can the effect of anti-psychotic drugs be tested?
- If ENHACE dopaminergic signalling –> give rise to positive Schizophrenia-like symptoms
- These positive symptoms are repetitive, non-productive motor behaviours
- These behaviours can be monitored in rodents before and after anti-psychotic drugs are given
- Can cause a rodent to exhibit these behaviours by giving repeated doses of amphetamines
What type of drugs are effects as anti-psychotics?
Antagonists of dopaminergic signalling
What are the flavours of dopamine receptors?
D1 and D2
D3,D4,D5
What are the D1 receptors?
What do they do when activated?
Gs coupled receptors
When activated:
- Increase the activity of adenylate cyclase
- Increasing effect on neurotransmission
What are the D2 receptors?
What do they do when activated?
Gi coupled receptors
When activated:
- Decrease the activity of adenylate cyclase
- Decreasing effect on neurotransmission
What neurons are D2 receptors also found on?
What do they do here?
Found on INHIBITORY interneurons
Here, they:
- Inhibit inhibition –> increase in transmission
Is the D4 receptor excitatory or inhibitory?
INHIBITORY