LECT 1 | Pierce

Question 1

What is the name of the system that is central to pleasure, reward and addiction?

Answer 1

Mesolimbic System

Question 2

Does _ activity in the nucleus accumbens activate or inhibit pleasure?

Answer 2

Inhibit pleasure

Question 3

Does _ activity in the ventral tegmental area (VTA) activate or inhibit pleasure?

Answer 3

Activate pleasure

Question 4

Which neurotransmitter is released by the nucleus accumbens (NA) to the prefrontal cortex?

Answer 4

GABA

Question 5

Which neurotransmitter is released by the ventral tegmemtal area (VTA) to the nucleus accumbens?

Answer 5

Dopamine

Question 6

Which neurotransmitters do the prefrontal cortex and lateral hypothalamic nucleus release to _ the VTA, repectively?

Answer 6

PFC_ EAA LHN_ orexin (from fooooood)

Question 7

Describe the negative feedback loop between the NA and VTA.

Answer 7

GABA and dynorphin from NA released back to VTA_ _ further DA release from VTA

Question 8

Describe the dopamine hypothesis of reward.

Answer 8

Dependence-producing drugs _ the mesolimbic DA system_ pleasure

Question 9

Explain an example of how a reward can be induced by dopamine-independent mechanisms.

Answer 9

Endogenous opioids also _ VTA via disinhibition of GABAergic neurons locally through -receptors _ DA from VTA_ _ NA_ pleasure

Question 10

Which neurons encode the discrepancy between reward predictions vs. actual reward?

Answer 10

Dopaminergic

Question 11

Describe the results of the following on the reward system: 1. Unpredicted reward 2. Fully predicted reward 3. Lack of predicted reward

Answer 11

1. Activation (positive prediction error) 2. No response 3. Depression (negative prediction error)

Question 12

Define long-term potentiation (LTP).

Answer 12

A persistent _ in synaptic strength following high-frequency stimulation of a chemical synapse

Question 13

What is the effect of CREB (cAMP response elements) in the nucleus accumbens?

Answer 13

Targets dynorphin

Question 14

Describe the mechanism of physical dependency.

Answer 14

CREB-dependent upregulation of target genes in locus coeruleus (LC)_ excessive noradrenergic output

Question 15

Do CREB-dependent mechanisms result in short-term or long-term changes?

Answer 15

Short-term changes

Question 16

List a couple things that activate _FosB.

Answer 16

Stress Drugs of abuse

Question 17

Activation of _FosB leads to _ expression of what (3)?

Answer 17

1. EAA receptors (AMPA/NMDA) 2. Elements of cell signaling 3. Factors promoting drug seeking, motivation, and locomotion

Question 18

Do _FosB-dependent mechanisms result in short-term or long-term changes?

Answer 18

Long-term (structural) changes

Question 19

Describe the role of NF-_B in terms of drug addiction.

Answer 19

Induced within NA and promotes growth of dendritic spines_ _ drug rewards

Question 20

Describe the effect of associative learning (conditioning) on dopamine firing in the VTA.

Answer 20

_ Phasic DA firing in the VTA_ fast, short-lived _ of DA in the NA, reflecting expectation of reward

Question 21

Describe the difference between natural rewards vs. drugs of abuse in regards to phasic dopamine firing in the VTA.

Answer 21

Natural reinforcers (food, sex, exercise): cease phasic DA firing when the event concludes Drugs of abuse: continue increasing DA release