Lecture 8- Stimulants II

Question 1

Proccess of L DOPA to Epinephrine

Answer 1

-L dopa is the product of L tyrosine
-From L-dopa to Dopa decarboxylase
-Creates dopamine
-Become norephedrine
-Becomes Epinephrine

Question 2

What is the rate-limiting step (slowest) in catecholamine synthesis

Answer 2

Tyrosine hydroxylase (TH)

Question 3

Dopamine was originally only believed to be

Answer 3

A precursor for NE and E, not it’s own NT

Question 4

How did Arvid Carlsson demonstrate that dopamine was a NT

Answer 4

-Removed dopamine from rabbits and gave it back
-Rabbits start to move again
-When they remove dopamine, they’re more catatonic

Question 5

Dopamine transporter also does what

Answer 5

Reuptakes dopamine

Question 6

In the brain all monoamines are packaged into vesicles by

Answer 6

VMAT2

Question 7

All monamines are degraded by

Answer 7

Monoamine oxidase

Question 8

In the striatum, what are the dopamine classes

Answer 8

-D1 class (D1,D5)
-D2 class (D2-4)

Question 9

D2 class features

Answer 9

-Receptors couple to inhibitory G protein
-Presynaptic Autoreceptors are usually D2

Question 10

D1 class features

Answer 10

-Receptors are usually coupled to stimulatory G proteins

Question 11

All dopamine classes can be

Answer 11

Postsynatic

Question 12

D1 and D2 class receptors are usually on different

Answer 12

Neurons

Question 13

Hundreds of thousands of DA, NE and 5-HT cells in the midbrain nuclei send

Answer 13

Broad, diffuse projections to large areas of the forebrain, suggesting these signals are global

Question 14

Striatum is divided into 2 main parts

Answer 14

-Nucleus accumbens
—Important for reward
-Dorsal striatum/ caudate putamen
—Involved in movement

Question 15

The striatum is a key site of

Answer 15

-Dopamine action
-Dopamine is important for striatal function

Question 16

A9, Substania nigra

Answer 16

-Project their axons to the dorsal striatum
-Nigrostriatal pathway

Question 17

A10, Ventral tegmental area (VTA)

Answer 17

-Projects their axons to the nucleus accumbens
-Mesolimbic pathway

Question 18

Dopamine terminals can be identified via

Answer 18

Tyrosine hydroxylase (TH staining)

Question 19

Amphetamines dopamine increase measured by microdialysis

Answer 19

-In the nucleus accumbens, 1000%
-In the dorsal striatum, 500%

Question 20

Cocaine dopamine increase measured by microdialysis

Answer 20

-In the nucleus accumbens, 300%
-In the dorsal striatum, 200%

Question 21

What’s the primary site of action of amphetamines and cocaine

Answer 21

Monamine transporters

Question 22

Distribution of cocaine matches that of

Answer 22

DAT

Question 23

Effects of cocaine blocking DAT

Answer 23

-High doses of cocaine can produce 2-4 times increase in striatal dopamine release
-Dopamine accumulates in the synaptic cleft

Question 24

Which produces a greater effect on momamines

Answer 24

Amphetamines more than cocaine

Question 25

Amphetamines effect on DAT

Answer 25

-Entry via DAT -Inhibits dopamine storage in vesicles through VMAT blockade -DAT works in reverse to remove dopamine from terminal to cleft

Question 26

Why when dopamine blockers are added do rats increase pressing a lever

Answer 26

Panic, want more drug, eventually drops when nothing is received

Question 27

What do DA and NE antagonists show about amphetamine reward

Answer 27

-DA blockers cause spike and drop in lever presses -NE is unchanged

Question 28

What blockers are not commonly abused by people

Answer 28

-NET -SERT

Question 29

Repeated treatment which procedures sensitisation of psychomotor also

Answer 29

Increases DA transmission

Question 30

Subjective high requires

Answer 30

40-60% DAT occupancy

Question 31

Cocaine has frequent administration due to

Answer 31

Fast uptake and clearance from the brain

Question 32

Dopamine terminals destroyed using

Answer 32

Toxin 6-OHDA

Question 33

What are stereotyped behaviours

Answer 33

Meaningless repetitive movement

Question 34

Psychostimulant microinjections into the nucleus accumbens cause

Answer 34

Increased locomotor behaviour

Question 35

Psychostimulant microinjections into the dorsal striatum causes

Answer 35

Increased stereotyped behaviours

Question 36

6-OHDA lesions to the nucleus accumbens causes

Answer 36

-Decreased locomotor response following systemic administration of low dose psychostimulants -Decreasing reinforcing effectiveness

Question 37

6-OHDA lesions to the dorsal striatum causes

Answer 37

Decreased stereotyped behaviours following systemic administration of high dose psychostimulants

Question 38

Amphetamine microinjection to the nucleus accumbens causes

Answer 38

Reinforcing to the animal

Question 39

Cocaine microinjection to the nucleus accumbens causes

Answer 39

Reinforcing to the animal

Question 40

Dopamine blockade in the dorsal striatum causes

Answer 40

Normal Acquisition of cocaine self administration

Question 41

Dopamine blockade in the nucleus accumbens causes

Answer 41

Disrupted acquisition of cocaine self administration

Question 42

Stimulant ‘bath salts’ contain

Answer 42

Cathinones such as MDVP

Question 43

How does bath salts differ to cocaine

Answer 43

-More DA release per mg of product -Increased heart rate