Week 4 Flashcards
What is psychopharmacology
Psychopharmacology is the study of the effects of drugs on the nervous system and behaviour
What are drugs, drug effects, and sites of action
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
What is pharmacokinetics
pharmacokinetics is all about the four steps to do with drugs, absorption, distribution, metabolism, excretion
What are the five possible ways of absorbing drugs
injection, oral, inhalation, insufflation, topical administration
Explain distribution of drugs in the body
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
Explain the process of metabolism and excretion of drugs
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
What is the dose response curve
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
What is the therapeutic index
The therapeutic index measures drugs margin of safety which is the toxic dose/therapeutic dose. A higher number means safer.
Why do drugs vary in effectiveness
drugs vary in effectiveness due to having differing sides of action as well as drug affinity
Explain sensitisation and tolerance
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.
Explain placebo
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.
What is an Antagonist
A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell
What is an Agonist
A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell
How do Agonists impact neurotransmitter synthesis
They can serve as precursors
The rate of neurotransmitter synthesis and release can increase (L-DOPA -> Dopamine)
How do antagonists impact neurotransmitter synthesis
The drug inactivates enzymes involved in NT synthesis, preventing NT production.
Eg; PCPA inhibits an enzyme which helps serotonin
How do agonists affect the storage and release of NT
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
How can agonists affect storage and release of NT
- 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
- 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 
How do agonists and antagonists impact receptors
Agonist: Drugs can stimulate postsynaptic receptors
Antagonist: Drugs can block postsynaptic receptors
How do agonists impact reuptake and deactivation
they can block the reuptake of neurotransmitters from the synaptic cleft. They can also in activate enzymes involved in enzymatic deactivation of a neurotransmitter
Explain Amino acid Neurotransmitters
most communication in the brain is done by 2 amino acid neurotransmitters. Glutamate which is excitatory and Gabba which is inhibitory
Explain glutamate (excitatory)
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
Explain GABA (inhibitory)
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
Explain Acetylcholine (ACh)
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
List monamine NT’s
Dopamine
Norepinephrine
Serotonin
Histamine
