psychosis

Question 1

What are the 3 biochemical theories of schizophrenia?

Answer 1

1. Dopamine Hypothesis
2. glutamate hypothesis
3. serotonin (5-HT) hypothesis

Question 2

What change to the dopamine system can cause symptoms of schizophrenia?

Answer 2

hyperactivity

Question 3

what are the two sources of evidence for the dopamine hypothesis?

Answer 3

1. drugs that increase dopamine can cause delusions

2. drugs that block dopamine receptors are effective antipsychotics

Question 4

Where is the largest population of dopamine neurons found in the brain?

Answer 4

midbrain (ventral segmental area and substantial nigra)

Question 5

what are the three systems of focus for dopamine neurons?

Answer 5

mesocortical/ mesolimbic system
nigrostriatal system
tuberinfundibular system

Question 6

Where is the mesocortical system located and where does it project to?

Answer 6

ventral segmental area

projects to striatum and prefrontal cortex

Question 7

what is the purpose of the mesocortical system?

Answer 7

memory, leaning, thoughts

Question 8

what effect does blocking dopamine transmission in the mesocortical area have?

Answer 8

reducing positive symptoms of schizophrenia

Question 9

What are the two types of dopamine receptors and how do they function?

Answer 9

D1 = Gs (adenylate cyclase)
D2 = Gi (inhibit adenylate cyclase)

Question 10

Where does the nigrostriatal system project to & where is it located?

Answer 10

projects to striatum

located in substantia nigra

Question 11

How does blocking the dopamine neurons in the nigrostriatal system effect the body?

Answer 11

tardive dyskinesias

Question 12

Where is the tuberoinfundibular system located and what does it do?

Answer 12

located in arcuate nucleus

controls hormone release in the pituitary

Question 13

how does dopamine blockage in the tuberoinfundibular system affect the body?

Answer 13

hyperprolactinemia (amenorrhea, decreased libido, infertility)

Question 14

What is the glutamate hypothesis?

Answer 14

deficiencies in glutamate signalling in cortex can cause symptoms of schizophrenia

Question 15

what is the evidence for the glutamate hypothesis?

Answer 15

NMDA antagonists produce hallucinations

Question 16

Describe the activity of the following in a schizophrenic individual according to the glutamate hypothesis:
NMDA receptors
GABA
Glutamate sugnallting 
Dopamine

Answer 16

hypofunctional
hypofunctional
hyperfunctional
hyperfunctional

Question 17

What is the evidence for the serotonin hypothesis?

Answer 17

1. 5-HT agonists that are hallucinogenic (LSD)

2. 5-HT antagonists improves positive stymtoms

Question 18

Describe the downstream effects of activation of 5HT-2A receptors in the prefrontal cortex?

Answer 18

excitation of glutamate neurons leading to activation of mesolimbic dopamine system

Question 19

what is the difference between typical and atypical antipsychotics?

Answer 19

typical = D1, D2
atypical = D2, 5HT

Question 20

What is haloperidol? Describe it’s kinetic activation?

Answer 20

1st generation,

fast on, slow off

Question 21

What is chlorpromazine? Describe is kinetic activity?

Answer 21

1st generation

fast on, fast off

Question 22

What is clozapine? Describe its kinetic mechanism?

Answer 22

2nd generation

slow on, fast off

Question 23

What is the unique side effect about clozapine?

Answer 23

affinity for D4 causing agranulocytosis