Reward pharm

Question 1

VTA and nucleus accumbens

Answer 1

reward and reinforcement. neural circuit connecting limbic emotional-motivational info and extrapyramidal regulation of motor behavior

Question 2

amygdala

Answer 2

formation of stimulus reward association. projects to VTA and nucleus accumbens

Question 3

hippocampus

Answer 3

memory circuit. mediates association between biologic stimuli and environmental cues

Question 4

prefrontal cortex

Answer 4

DLPFC = executive function –> control over impulses from destructive behavior

Question 5

dopamine in reward system

Answer 5

released from VTA to nucleus accumbens –> motivation and attention to salient stimuli. normally triggered by natural cues like food, water, sex

Question 6

drugs of abuse and their effect on dopamine

Answer 6

more intense and direct increase of nucleus accumbens dopamine levels –> greater addiction potential (esp. cocaine, meth, nicotine)

Question 7

reactive reward system

Answer 7

VTA, NA, amygdala –> immediate prospect of postitive/negative consequences –> motivational drive to achieve/avoid

Question 8

amygdala in reactive reward system

Answer 8

glutamate –> nucleus accumbens (emotional response, impulsivity) –> GABA secretion

glutamate –> VTA (relevance detection) –> dopamine to amygdala (reward learning), dopamine to nucleus accumbens (“bursting reward”, fun, potentiation of conditioned reward)

Question 9

addiction

Answer 9

repeated drug exposure –> pathologic “learning” to trigger drug-seeking behaviors

Question 10

reflective reward system

Answer 10

connections from PFC to nucleus accumbens –> final decision with integrated emotions, affect, analysis, impulses and cognitive flexibility

OFC –> impulses
VMPFC –> integrates impulses and cognitive flexibility with emotions
DLPFC –> analysis

Question 11

orbitofrontal cortex connectivity

Answer 11

glutamate to VMPFC and nucleus accumbens

Question 12

VMPFC connectivity

Answer 12

glutamate from OFC and DLPFC

glutamate to nucleus accumbens

Question 13

DLPFC connectivity

Answer 13

glutamate to VMPFC and nucleus accumbens

Question 14

balance between reactive/reflective reward systems

Answer 14

output converted to short-term rewards (drug-seeking) or long-term rewards

Question 15

pharmacodynamics and drug abuse potential

Answer 15

intense euphoria or relief of negative effect –> abuse potential

greater enhancement of DA in nucleus accumbens –> greater dependence liability

Question 16

drugs with greatest dependence liability

Answer 16

cocaine, meth > nicotine, opioids > alcohol, benzodiazepines > hallucinogens, dissociative anesthetics

Question 17

Pharmacokinetics and drug abuse potential

Answer 17

increased rate of onset –> increased abuse potential

shorter half-life –> more frequent administration –> greater abuse potential; continuous administration to avoid withdrawal

Question 18

pharmacogenetics and drug abuse potential

Answer 18

less ability to metabolize drug –> less likely to become addicted

Question 19

which ethnicity is at lower risk of alcoholism?

Answer 19

asian. lack acetaldehyde dehydrogenase