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Flashcards in Schizophrenia Deck (17)
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1

What is schizophrenia

Characterised by disturbances in areas of the brain associated with thought, perception, attention, motor behaviour and emotion

2

What are the two classes of symptoms

Positive - hallucinations, delusions, thought disorders
Negative - Blunting of emotions, withdrawal from social contact, reluctance to perform everyday tasks

3

What are some causes of schizophrenia

Environmental and genetic factors
Affected by illegal drugs i.e. cocaine, opiates - all induce the positive symptoms of schizophrenia

4

What are the four pathways of dopamine in the body

1.Nigrostriatal pathway - fine motor control
2. Mesocortical and mesolimbic pathways - behavioural effects, pleasure - euphoria - reward (motivation), compulsion
3. Tuberohypophyseal pathway - pituitary secretion i.e. prolactin
4. Medullary chemoreceptor trigger zone - nausea and vomiting

5

What is the cause of schizophrenia in response to dopamine

Excessive activity of the dopamine system

6

How is dopamine synthesised

Derived from tyrosine
Rate limiting step - tyrosine to L-Dopa- catalysed by tyrosine hydroxylase
L-Dopa to dopamine catalysed by Dopa decarboxylase

7

What type of receptor are dopamine receptors

GPCRs only - D1,3,5 are excitatory
activation leads to an increase in cAMP

D2,4 are inhibitory leading to a decrease in cAMP

8

What is the role of D2 receptors

Control the function of the dopamine releasing neurons - involved in autoregulation

9

How is dopamine metabolised

By MAO and COMT

10

What are antipsychotic drugs

Almost all act on D2 receptors and are antagonists

11

What are two first generation antipsychotics

Chlorpromazine, Haloperidol

12

What are extrapyramidal motor disturbances due to D2 antagonism

D2 receptors found in the nigrostriatal pathway causes involuntary movements defined as extrapyramidal motor disturbances

13

What are atypical antipsychotics

Have a lower incidence of extrapyramidal effects - no secretion of prolactin

14

What can prolonged usage of antipsychotics cause

Can become neurotoxic - degeneration of aminergic neurons as a result of accumulation of reactive metabolites within the neurons themselves

15

What can acute use of antipsychotics cause

Euphoria and excitement - effects on mesocortical and mesolimbic pathways - presents as hyperactivity
Insomnia
Increase in stamina
Anorexia - disturbed feeding behaviour
Peripheral effects - sympathomimetics in PNS cause increased blood pressure and decreased gut motility

16

What occupancy is required in order to alleviate symptoms

80%

17

What does hyper prolactin secretion cause

Breast development in men