Drugs Of Abuse

Question 1

Which pathway is reward pathway to reinforce behaviour

Answer 1

Dopaminergic

Question 2

Where are DA cell bodies found in dopaminergic reward pathway

Answer 2

VTA

Question 3

Where does signalling go to from the VTA da body

Answer 3

Ventral striatum (dorsal striatum is to do with Parkinson’s)

Then to pre frontal cortex

Question 4

What is the nucleus called on the ventral striatum where D2 receptors are for VTA dopamine release

Answer 4

Nucleus accumbens

Question 5

Which things stimulate both the n accumebns and VTA

Answer 5

Glutamate EPSP which binds to nmda receptors causing AP

Question 6

Which things are inhibitory for the VTA and also for n accumbens

Answer 6

Gaba ipsp

Question 7

What do amphetamines do

Answer 7

Increase levels of monoamines (da, nadr, 5HT) in synapse

Question 8

What does amphetamine structure look like

Answer 8

Other monoamines eg DA and nadr and 5HT

Question 9

How do amphetamines enter which blocks reuptake

Answer 9

Via reuptake transporters (Dat, nat, 5htt )

Question 10

How do amphetamines once in via reuptake transporters get inserted to vesicle

Answer 10

Via VMAT2

Question 11

What does insertion to vesicles via VMAT 2 cause

Answer 11

Ph levels lower in vesicle to release monoamines eg nadr, da, 5HT

Question 12

What allows for the transport of the NT from vesicle to the cleft when amphetamines enter via vmat2

Answer 12

Reuptake transporters reverse due to higher conc in cytosol than cleft

These therefore carry the Monoamines in cleft and blocks reuptake

Question 13

What would happen if DAT was targeting via amphetamines

Answer 13

DA would increase in cleft

Causes psychosis and reward stimulation

Question 14

What would happen is NAT was the highest affinity

Answer 14

Nadr would increase in cleft and cause alertness, anxiety

Question 15

What actions would occur if 5HT was increased in synapse

Answer 15

Anoretic and empathogenic behaviours

Question 16

Where does dopamine increase due to amphetamines in the reward pathway

Answer 16

More released from the VTA to then bind to D2 on n accumbens (ventral striatum)

Question 17

How does cocaine work to increase DA in the synapse between VTA and n accumbens

Answer 17

Blocks the DAT reuptake transporters (as well as nat and 5htt)

Question 18

Why does crack cocaine have quicker and larger effect

Answer 18

Lipophillic to enter brain and faster action

Question 19

Which receptors on VTA does nicotine bind to to cause stimulation and therefore release of DA from VTA

Answer 19

Nicotinic acH receptors (cusses AP)

Question 20

What substance causes psycho activity from cannabis

Answer 20

9 THC

Question 21

Which gcpr does THC from cannabis bind to

Answer 21

Cb1 and cb2

Question 22

Are cb1 presynpstic autorecepotrs

Answer 22

Yes

Question 23

What binds to CB1 to cause stoped release of things like gaba

Answer 23

Cannabinoids

Question 24

How can cannabinoids increase DA release from VTA

Answer 24

If they bind to CB1 on ipsp neurones which stops release of gaba

= disinhibit the VTA

Question 25

Can cannabinoids also stop release or EPSP eg glutamate via cb1

Answer 25

Yes

Question 26

Which receptors do opiates bind to causing rewarding effects (increase in DA from VTA and n accumbens)

Answer 26

Mu receptors

Question 27

What happens when opiates bind to mu receptors

Answer 27

Prevents the release of gaba from IPSP

Disinhibits the VTA and n accumbens

= increase in DA