Pharmacology of Reward - French

Question 1

Rate the following methods of drug administration from fastest onset to slowest: IV, insufflation, subcutaneous, inhalation, oral

Answer 1

Inhalation > IV > insufflation = subcutaneous > oral

7 seconds, 15 seconds, 3-5 minutes, 30 minutes, respectively.

Question 2

A. What properties increase the addictive character of a drug?

B. What pharmacokinetic property makes withdrawals more severe?

Answer 2

A. Rapidity and intensity of onset increase addictive potential.

Shorter half-life increases addictive potential due to more frequent administrations.

So, the intravenous and inhalational routes are associated with the most rapid rise in brain levels of the drug and a greater likelihood to produce addiction. (Eg crack vs cocaine).

B. Withdrawal effects > for short t 1/2. More frequent administrations to avoid effects.

Question 3

A genetic impairment to nicotine metabolism will have an (increased or decreased) risk for addiction?

For alcohol?

Answer 3

Both will be decreased due to nausea, vomiting, etc.

Increased protection against addiction.

Question 4

All drugs with significant dependence liability share the pharmacologic property of _____.

Answer 4

enhancing dopamine activity in the nucleus accumbens.

[directly or indirectly through several different neurotransmitter systems and via several different mechanisms.]

Question 5

What is thought to be the final common pathway of reinforcement and reward?

Answer 5

Mesolimbic pathway.

VTA–> NAc

Stimulation of the VTA by sensory pathways causes release of dopamine in the NAc.

Most drugs of abuse also stimulate this pathway.

Question 6

Describe the reactive reward system.

What is its purpose?

Answer 6

VTA, NAc, amygdala.

VTA projects to NAc, amygdala projects to both.

Signals the prospect of pleasure/pain, and causes a seeking or avoidance response, respectively.

Question 7

Describe 3 parts of the reflective reward system and their function.

Answer 7

3 structures that synapse on the NAc.

• Orbitofrontal projections (OFC) –> regulating impulses
• Dorsolateral prefrontal projections (DLPFC) –> situational analysis
• Ventromedial prefrontal (VMPFC) –> impulses

Question 8

Without the reflective reward system input, what happens?

Answer 8

The reactive system takes over (eg initiation of drug-seeking behavior).

Question 9

Opioids:

Give action/location.

Answer 9

Agonists at μ-opioid receptors [Gi]

Question 10

CNS Depressants:

Give action/location.

Answer 10

Enhance GABA and/or inhibit glutamate fxn

Question 11

CNS Stimulants:

Give action/location.

Answer 11

Block DA reuptake or enhance DA release

Question 12

Nicotine:

Give action/location.

Answer 12

Agonist at nicotinic neuronal receptors

Question 13

Hallucinogens:

Give action/location.

Answer 13

Partial agonist at 5HT2 receptors (DA releaser)

Question 14

Dissociative Anesthetics:

Give action/location.

Answer 14

Antagonist at NMDA-Glu receptors

Question 15

Cannabinoids:

Give action/location.

Answer 15

Agonist at cannabinoid (CB1-CB2) receptors

Question 16

Differentiate between cross-tolerance and cross-dependence.

Answer 16

Cross tolerance–> use of one leads to decrease effects in the other

Cross dependence–> withdrawal of one class countered by addition of a similar class

Question 17

Treat acute opioid toxicity with ___.

Treat opioid withdrawal with ___.

Answer 17

Naloxone

Clonidine, methadone.