Drug properties

Question 1

Dopamine projects from which area of the brain to each area?

Answer 1

Ventral Tegmental Area (VTA) to Nucleus Accumbens (NAcc)

Question 2

All addictive drugs directly or indirectly…

Answer 2

Affect dopamine transmission

Question 3

Serotonin is produced in and distributed from the…

Answer 3

The raphe nuclei (brain stem)

Question 4

Serotonin depleted people are…

Answer 4

more irritable, and worse at stroop test

Question 5

The serotonin’s precursor is _______. What does that mean?

Answer 5

tryptophan

It means, in our body: tryptophan -> chemical reaction -> serotonin

Question 6

Hallucinogens act on ________ receptors

Answer 6

Serotonin

Question 7

Serotonin receptors are…

Answer 7

Mostly Metabotropic - only one type of ionotropic

Question 8

What are Selective serotonin Reuptake inhibitors (SSRIs) ?

Answer 8

Block serotonin from being removed from the synapse

Acts immediately but takes longer to actually make changes because what makes a difference are the chain reactions

Question 9

SSRI efficacy mild to moderate depression

Answer 9

little difference between placebo and SSRIs

Question 10

SSRI efficacy Severe depression

Answer 10

SSRIs help individuals, but the effect size is small: so should not be just used on their own. Also: Regression to the mean.

Question 11

Acetylcholine

Neuromuscular junction

Answer 11

The first neurotransmitter that was ever discovered because it is released into the muscle tissue. Ionotropic receptors

Question 12

Acetylcholine

Major function in the…

Answer 12

basal forebrain: Wakefulness, attention, arousal, etc.

Question 13

Nicotine binds to ___________ receptors:

Answer 13

Acetylcholine

Agonist drug on acetylcholine (nicotinic) receptors

Question 14

Endocannabinoids

How do they work on the synapse?

Answer 14

Travel from dendrite to axon, i.e. retrograde transmission (Endocannabinoid neurotransmitters come from postsynaptic and bind to the presynaptic terminal)
Weaken connection between two cells at synapse
Metabotropic receptors

Question 15

Endocannabinoids

Function in the brain

Answer 15

Mechanism for forgetting or negative feedback mechanism, we are not sure
Weakens the synapse - Causes less neurotransmitters to be released

Question 16

Adenosine

What is it?

Answer 16

Comes from ATP (cellular energy) - it’s its byproduct
ATP -> ADP -> AMP -> Adenosine
Our body accumulates adenosine as it breaks ATP down

Question 17

Adenosine in the brain

Answer 17

Brain has adenosine receptors: when adenosine binds it inhibits
The more you are awake -> more adenosine -> more receptors inhibit neurons

Question 18

Adenosine and caffeine

Answer 18

Caffeine is an adenosine receptor blocker (adenosine antagonist) -
but temporary - the NT builds up on the synapse
Your body creates more adenosine receptors (adaptation), which leads to tolerance

Question 19

Endogenous opioids aka Endorphins

What are they?

Answer 19

Giant peptide neurotransmitters

System to block the pain - also involved with euphoric effects

Question 20

Endogenous opioids aka Endorphins

Drugs

Answer 20

The neurotransmitter system that exogenous opioids (e.g. heroin) mimic
Fentanyl (opioid receptor agonist) and naloxone (opioid receptor antagonist)

Question 21

Endogenous opioids aka Endorphins

Receptors (what and where)

Answer 21

Receptors are all GPCRs (G protein coupled receptors)

Receptors found in spinal cord, periaqueductal grey (PAG), nucleus accumbens, more.

Question 22

Pharmacokinetic

What and steps

Answer 22

Drug’s passage through the body
Liberation, Absorption, Distribution (reach site of action), Biotransformation (Drug broken down by enzymes), Elimination

Question 23

Absorption

Routes of administration

Answer 23

From high short effects to low long effects - Intravenous, intramuscular, subcutaneous, per os (by mouth) 
Also inhalation (smoke) or insufflation (snort, through mucous membranes)

Question 24

Absorption

Environmental pH

Answer 24

If a drug is basic it is more likely to be absorbed in a basic area
If a drug is acidic it is more likely to be absorbed in a acidic area

Question 25

Drug pKa

Answer 25

Drug level of acidity

Question 26

Distribution

Bioavailability

Answer 26

• The ability for the drug to reach its site of action (target)

Question 27

Things that affect bioavailability

Answer 27

Blood-brain barrier and Nonspecific binding
Blood-brain barrier - molecules that have more chance to pass: lipid soluble, small and not have a lot of polarity
Nonspecific binding - When chemicals get lost along the way, before binding to the site of action. It binds in other places.

Question 28

First-pass metabolism

Answer 28

Drug starts breaking down before it reaches site of action

Question 29

Active metabolites

Answer 29

Some drugs, as they are metabolized, turns into other drugs

Question 30

Prodrugs

Answer 30

Are not drugs, but once metabolized they become a drug.
Example: L-DOPA crosses the blood brain barrier and then is converted into dopamine, while dopamine cannot cross the barrier

Question 31

Pharmacodynamics

Answer 31

How the drug works
Agonism, antagonism, etc
Binding affinity - cf. Dissociation constant, Ka
Receptor efficacy

Question 32

Tolerance

Answer 32

The need for a higher dose for the same effect. Is not fix, it is usually dependent on the environment.

Question 33

Tolerance and environments

Answer 33

Most people overdose in novel environments, even with the same usual dose. Higher mortality rate in novel environments. Our bodies get ready for the drug to be present when it feels that it is coming. A new environment gets your body off guard.

Question 34

Sensitization

Answer 34

Opposite of tolerance. increased effect of drug following repeated doses

Question 35

Dependence

Answer 35

An adaptation has developed such that our body expects the drug to be there.
It is a feature of addiction but is not addiction. Can have dependence without addiction.
Leads to withdraw if drug not there.