Physiology of Reward and Addiction

Question 1

What is a negative regulator of the reward system?

Answer 1

Dynorphin

Question 2

Projections from what is an activator of the ventral tegmental area dopaminergic neurons that result in reward?

Answer 2

Hypothalamus

Question 3

Physical dependence is due to excessive output of what?

Answer 3

Noradrenergic output from locus coeruleus

Question 4

Action of what is implicated in the changes to synapse that mediates addiction in the long-term (years)?

Answer 4

Delta-FosB

Question 5

Treatment of withdrawal symptoms is believed to be due to action on?

Answer 5

Noradrenergic neurons in the locus coeruleus

Question 6

Excessive noradrenergic output from the locus coeruleus leads to?

Answer 6

Physical dependency

Question 7

What explains physical dependency?

Answer 7

CREB-dependent upregulation of target genes involved in learning and memory within the locus coeruleus

Question 8

A persistent increase in synaptic strength following high frequency stimulation of a chemical synapse is known as?

Answer 8

LTP

Question 9

What is the long term mechanism of LTP?

Answer 9

Activation of calcium-calmodulin-CREB mechanism

Question 10

CREB upregulation leads to the transcription of what?

Answer 10

Dynorphin

Question 11

CREB is only shorter acting (days) and returns to normal levels after?

Answer 11

Drug cessation

Question 12

What is the term for the attention grabbing feature of rewarding objects or the wanting of reward?

Answer 12

Salience

Question 13

If an object has salience to an individual, how do they view that object?

Answer 13

It has value to them so they want it

Question 14

What is the term for a subjectively positive sensation often referred to as euphoria and having great interest in it?

Answer 14

Pleasure/Hedonia

Question 15

What is the term for for the lack of interest in something or no longer liking something previously liked?

Answer 15

Anhedonia

Question 16

If a drug is consumed that disrupts neural inputs from the prefrontal cortex to the nucleus accumbens, what NT is most likely affected?

Answer 16

Glutamate

Question 17

If activity in the ventral tegmental area is decreased, what is the consequence?

Answer 17

Decreased release of dopamine into nucleus accumbens

Question 18

What is the default state of the reward system?

Answer 18

Absence of pleasure

Question 19

GABAergic neurons release GABA in the?

Answer 19

PFC

Question 20

Activation of what will inhibit or prevent pleasure?

How?

Answer 20

Nucleus Accumbens by blocking PFC

Question 21

What structures activate the nucleus accumbens?

Answer 21

1) PFC (w/ EAA)
2) Hippocampus
3) Amygdala

Question 22

The ventral tegmental area sends what type of projections to the NA?

Answer 22

Dopaminergic

Question 23

What happens to the NA when dopamine is released into it?

Answer 23

It is inhibited resulting in pleasure

Question 24

What activates the VTA?

Answer 24

1) EAA from PFC
2) Ach
3) Orexin from lateral hypothalamic nucleus (food)

Question 25

When can NA send back to VTA in order to inhibit further dopamine release?

Answer 25

GABA with it’s cotransmitter Dynorphin

Question 26

Dynorphin acts through what type of receptors?

Answer 26

kappa-opioid receptors

Question 27

How do opioids act on the reward system?

Answer 27

Increase pleasure by increasing dopamine in the VTA by inhibiting GABAergic neurons

Question 28

Opioids act through what type of receptors?

Answer 28

mu-receptors

Question 29

The mu-receptors allow opioids to do what?

Answer 29

Increase dopamine in the NA

Question 30

What does exercise activate in the reward system?

Answer 30

Endogenous opioids inputs upon the VTA

Question 31

Drug abuse and/or chronic stress can lead to the activation of FosB and AP-1, what do theses TFs promote?

Answer 31

Drug seeking, motivation, and locomotion