reward pathway

Question 1

reward pathway

Answer 1

ventral tegmental -> nucleus accumbens -> PFC

• dopaminergic mesolimbic pathway
• activated in response to expectation of rewards

Question 2

problem with theory that dopamine release produces feelings of pleasure

Answer 2

no effect of catecholamine depletion on cocaine induced euphoria
- DA isn’t enough to explain euphoria

Question 3

liking system

Answer 3

hedonic hotspots

Question 4

DA neuronal firing signals the difference between prediction and actual occurrence of rewards

Answer 4

novel stimulus -> increased firing
presentation of reward -> increased firing
CS -> increased firing then not to reward
no reward -> decreased firing

Question 5

what neurobiological factors contribute to cravings from withdrawal

Answer 5

reduced DA receptor availability impairing the ability to experience natural rewards

Question 6

neuroadaptation hypothesis

Answer 6

• within system: progressive downregulation
• between-system: anti-reward system

Question 7

anti-reward system

Answer 7

opposing response after initial stimulus ends
- brake on reward
- mediate aversive effects

Question 8

ventral-dorsal shift

Answer 8

impuslive -> compulsive
nucleus accumbens (ventral) -> caudate putamen (dorsal)

Question 9

disruption of PFC/NAcc glutamatergic pathway causes:

Answer 9

• impair response inhibition + impulse control

Question 10

deltafosB

Answer 10

transcription factor that is overly expressed in chronic drug use

• may play a role in transition from controlled drug use to addiction
• involved in glutamate transmission
• DNA methylation -> down reg
• histone acetylation -> up reg

Question 11

brain changes in addiction

Answer 11

• reduced gray matter
• PFC abnormalities
• different brain glucose metabolism

Question 12

impaired response inhibition and salience attribution model

Answer 12

Reduced striatal D2 receptor
levels -> deficits in
the PFC