Week 4

Question 1

What is psychopharmacology

Answer 1

Psychopharmacology is the study of the effects of drugs on the nervous system and behaviour

Question 2

What are drugs, drug effects, and sites of action

Answer 2

Drugs: an exogenous chemical not necessary for normal cellular functioning that significantly alters the functions of certain cells of the body when taken in low doses

Drug effects: observable changes in an individuals physiology and behaviour

Sites of action: the locations where drug molecules interact with molecules on or in cells to affect biochemical processes

Question 3

What is pharmacokinetics

Answer 3

pharmacokinetics is all about the four steps to do with drugs, absorption, distribution, metabolism, excretion

Question 4

What are the five possible ways of absorbing drugs

Answer 4

injection, oral, inhalation, insufflation, topical administration

Question 5

Explain distribution of drugs in the body

Answer 5

Drugs exert effects on sites of actions which are on our neurons. Lipid solubility is how quickly a drug can get into the CNS and cross the BBB

Question 6

Explain the process of metabolism and excretion of drugs

Answer 6

drugs are metabolised and deactivated by enzymes that are in the brain liver and blood.
All drugs are eventually excreted, enzymes can sometimes transform molecules of a drug into other forms that are also active which creates long-lasting drug effects

Question 7

What is the dose response curve

Answer 7

despite the relationship between drug dose and drug effects. There is a point where increasing the dose does not produce a stronger effects of the drug on this curve

Question 8

What is the therapeutic index

Answer 8

The therapeutic index measures drugs margin of safety which is the toxic dose/therapeutic dose. A higher number means safer.

Question 9

Why do drugs vary in effectiveness

Answer 9

drugs vary in effectiveness due to having differing sides of action as well as drug affinity

Question 10

Explain sensitisation and tolerance

Answer 10

sensitisation is an increase in the effectiveness of a drug that is administered repeatedly.

Tolerance is a decrease in the effectiveness if that drug is administered repeatedly.

Question 11

Explain placebo

Answer 11

Placebo = inert substance that is given to an organism in lieu of a psychologically active drug

Placebo effect = if a person expects that a placebo can have a physiological or psychological effect, then administration of the placebo could produce the expected effect.

Question 12

What is an Antagonist

Answer 12

A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell

Question 13

What is an Agonist

Answer 13

A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell

Question 14

How do Agonists impact neurotransmitter synthesis

Answer 14

They can serve as precursors

The rate of neurotransmitter synthesis and release can increase (L-DOPA -> Dopamine)

Question 15

How do antagonists impact neurotransmitter synthesis

Answer 15

The drug inactivates enzymes involved in NT synthesis, preventing NT production.
Eg; PCPA inhibits an enzyme which helps serotonin

Question 16

How do agonists affect the storage and release of NT

Answer 16

Drugs can stimulate the release of NT into the synapse. Bind with proteins that cause synaptic vesicles to fuse with membrane and release NT into the synapse

Question 17

How can agonists affect storage and release of NT

Answer 17

1. drugs can prevent the storage of neurotransmitter in vesicles in terminal button of a neuron. Vesicle transporter molecules on the synaptic vesicle membrane which help neurotransmitters get into vesicles can be blocked by drugs
2. drugs can prevent the release of neurotransmitter into the Synapse. Deactivate proteins that cause synaptic vesicles to fuse with membrane and release neurotransmitter into the synapse 

Question 18

How do agonists and antagonists impact receptors

Answer 18

Agonist: Drugs can stimulate postsynaptic receptors
Antagonist: Drugs can block postsynaptic receptors

Question 19

How do agonists impact reuptake and deactivation

Answer 19

they can block the reuptake of neurotransmitters from the synaptic cleft. They can also in activate enzymes involved in enzymatic deactivation of a neurotransmitter

Question 20

Explain Amino acid Neurotransmitters

Answer 20

most communication in the brain is done by 2 amino acid neurotransmitters. Glutamate which is excitatory and Gabba which is inhibitory

Question 21

Explain glutamate (excitatory)

Answer 21

It is synthesised from a precursor amino acid by an enzyme and pumped into synaptic vesicles.
On the postsynaptic neuron: 3 ionotropic receptors (NMDA, AMPA, Kainate) and 1 metabotropic glutamate receptor.
NMDA receptor is voltage and NT dependent.
Glutamate is removed via reuptake and broken down into enzymes

Question 22

Explain GABA (inhibitory)

Answer 22

Made from a precursor amino acid via an enzyme pumped into synaptic vesicles by vesical Gabba transporters

GABA A receptors are ionotropic and have at least 5 different binding sites, and other ligands (hormones)

Removed via reuptake

Question 23

Explain Acetylcholine (ACh)

Answer 23

PNS = muscle contraction
CNS = Dorsolateral pons (REM sleep and dreaming
Basal Forebrain (perceptual learning)
Medial septum (memory formation

synthesised from 2 pre-cursors by an enzyme and loaded into vesicles via vesical ACH transporters

Ionotropic receptors in PNS
Metabotropic receptors in CNS

Question 24

List monamine NT’s

Answer 24

Dopamine
Norepinephrine
Serotonin
Histamine

Question 25

Explain dopamine

Answer 25

Produces EPSPs. It acts through 3 pathways;

1. Nigrostriatal system = movement control
2. Mesolimbic system = reward and reinforcement
3. Mesocortical system = memory and problem solving

It has 5 types of metabotropic receptors

Question 26

Explain norepinephrine

Answer 26

Found in CNS and PNS.
It’s most important system originates in the locus coeruleus which is located in the dorsal pons and related to vigilance.

Released via axonal varicosities

Question 27

Explain serotonin (5-HT)

Answer 27

Relates to; mood regulation, sleep, eating, arousal and pain regulation.

Clusters of serotonin originate in the raphe nuclei of the midbrain, pons and medulla. This projects to the cortex + basal ganglia.

Question 28

Explain histamine

Answer 28

Plays critical role in wakefulness.

Found exclusively in the tuberomammillary nucleus (TMN) in the posterior hypothalamus

Question 29

Explain peptide NT’s

Answer 29

peptides are synthesised from large precursor molecules broken down into smaller neurotransmitter molecules by enzymes located in the neuron Soma. Often co released alongside another neurotransmitter to regulate the sensitivity of pre-synaptic or postsynaptic receptors. Most are neuro modulators. Direct agonists = heroin, direct antagonist = naloxone. There is no reuptake process

Question 30

explain Lipid NT’s

Answer 30

Lipids are fatty substances.
substances derived from lipids connectors neurotransmitters to send messages within or between cells.

They are synthesised on demand.

Relates to THC and paracetamol