Lecture 7

Question 1

What are anti-psychotics?

Answer 1

drugs that target amine neurotransmitters

Question 2

What is schizophrenia?

Answer 2

symptoms are characterised by mood, motor behaviour, perception, thought
1.1%prevalance- 250,000 in the UK
Unstable moods and emotion with unproductive repetitive behaviour

Question 3

What are some causes of schizophrenic symptoms?

Answer 3

Meth and cocaine

arise due to imbalance of dopamine signalling

Question 4

What are the symptoms of positive schiz?

Answer 4

More prevalent in the young 
aggression 
catatonia
hallucinations, delusions 
repetitive and predictable behaviour 
defect in selective attention

Question 5

What are the symptoms of negative schiz?

Answer 5

more prevalent in the elderly 
reluctant to perform everyday tasks 
negative state of mind
blunting of emotions 
flattening of emotional responses 
withdrawal from social contacts 
anhedonia

Question 6

What are cognitive deficits?

Answer 6

attention, memory and learning

Question 7

What are the causes of schiz?

Answer 7

Is hereditary as a result of failure to develop NS- can arise early or later in life
Genome wide studies show that there is no single channel cause but there are structural differences= larger lateral ventricles and smaller left temporal lobe

Question 8

What drugs give rise to positive schiz symptoms?

Answer 8

Drugs that enhance dopamine signalling e.g. meta amphetamines
Glutamate antagonist and 5HT agonist (LSD)

Question 9

What is the function of D1 and D5 receptors?

Answer 9

Are Gs coupled receptors that activate adenylate cyclase for increase in neurotransmission

Question 10

What is the function of D2,3 and 4 ?

Answer 10

Are Gi coupled receptors that inactivate adenylate cyclase to inhibit neurotransmission on inhibitory neurons

Question 11

How does DOPA effect mental health?

Answer 11

Is implicated in cognitive defects, learning, attention, movement
Is the primary NT affected by illegal drugs e.g. cocaine, amphetamines, opioids
Associated with primary schiz symptoms

Question 12

What parts of the brain are associated with schiz dopa activity?

Answer 12

1) Nigrostriatal pathway= motor control (lost in Parkinson’s)
2) Mesocortical and mesolimbic= euphoria, perseverance, pleasure,
3) Tubularhypophyseal pathway= pituitary gland- involved in the release of hormones e.g. prolactin
4) Medullary chemoreceptor trigger zone= nausea and vomiting

Question 13

Describe the synthesis of dopamine

Answer 13

tyrosine (tyrosine hydroxylase= DOPA
DOPA (DOPA decarboxylase)= dopamine
dopamine (Dopamine B hydroxylase)= noradrenaline
noradrenaline (PNMT)= adrenaline

Question 14

Why is it difficult to find drugs that specify for dopamine inhibitors?

Answer 14

Because dopamine is a precursor for other amine neurotransmitters therefore their ligand binding sites on the Rs are similar due to their similar structures

Question 15

How do D2 receptors work and how is DA handled?

Answer 15

They feedback to inhibit their own neurotransmission

They are taken up and degraded by COMT and MAO to produce DOPAC and HVA

Question 16

What’s a treatment of Parkinson’s and how does it affect schiz?

Answer 16

Administration of L-DOPA to increase dopamine synthesis

Increases schiz symptoms of hallucinations etc

Question 17

How do illegal drugs work e.g. amphetamines and cocaine and what are their symptoms?

Answer 17

Cause schizophrenic like symptoms as they increase the duration of catecholamines at the nerve terminal by inhibiting MAOs resulting in the pumps working in reverse (accumulate in the neuron and will travel back out). They increase euphoria, sympathetic systems, reward, increase in motor systems. Result in neurotoxicity as the metabolism of dopamine creates a reactive intermediate which results in neuronal cell death.

Question 18

What are amphetamines used to treat?

Answer 18

Narcolepsy and ADHD

Question 19

What are NMDA R antagonists cause?

Answer 19

They cause positive and negative schiz symptoms which proves that glutamate is involved e.g. ketamine and phencyclidine

Question 20

What is used to treat schizophrenia?

Answer 20

D2 receptor antagonists to decrease positive symptoms of schiz associated with the mesolimbic pathway

Question 21

What are the side effects of halperidal and chlorpromazine?

Answer 21

They are antipsychotic
motor disturbances
prolactin release
activation of nigral striatal pathway

Question 22

What is risperidone?

Answer 22

Anti-psychotic

5HT 2a, D1 and D2, alpha 1 and H1

Question 23

What is clozapine?

Answer 23

antipsychotic

same as risperidone but also mACHR

Question 24

Sulpiride

Answer 24

More specific to D2= less side effects

anti-psychotics

Question 25

Phenothiazine e.g. chlorpromazine

Answer 25

anti-psychotic
preference to D2
side effects= acute dystonia (reversible) and tardive dyskinesia (irreversible)