Neurophysiology of Reward and Addiction

Question 1

Motivation

Answer 1

process that mediates goal directed responses or goal seeking behavior to changes in internal/external environemnt

Question 2

Saliency

Answer 2

something important in the surrounding environment worth paying attention to

Question 3

Reward

Answer 3

something that has positive value

Question 4

Aversion

Answer 4

negative reinforcement of behavior that the individual will learn to avoid future encounters

Question 5

pleasure

Answer 5

• positive sensation

- physiological purpose = promote behaviors of survival

Question 6

Prediction error

Answer 6

• discrepancy between the reward and its prediction

- encoded by dopamine neurons

Question 7

positive prediction error

Answer 7

unpredicted reward

Question 8

no prediction error response

Answer 8

fully predicted wrror

Question 9

Omission of a predicted reward induces…

Answer 9

depression

Question 10

How does the repeated use of drug affect reward prediction error?

Answer 10

RPE signals continue to reinforce the drug related cues and behaviors

Question 11

What do natural rewards produce that makes them different than drug induced rewards?

Answer 11

error correcting dopaminergic RPE signals only until the predictions match the actual events

Question 12

Which NT is associated with the reinforcing effects of most drugs of abuse?

Answer 12

dopamine

Question 13

Where do drugs of abuse increase extracellular dopamine?

Answer 13

• limbic regions
• nucleus accumbens
• provide longer and larger increases in dopamine than natural reinforcers

Question 14

What are the two ways in which drugs can increase dopamine?

Answer 14

1) direct- inhibit dopamine reuptake, promote dopamine release (cocaine, amphetamine, meth, ectasy)
2) indirect- via other receptors that modulate dopamine levels (nicotine, alcohol, opiates, marijuana)

Question 15

What does the mesolimbic system consist of?

Answer 15

• nucleus accumbens
• VTA
• limbic system
• prefrontal cortex