Psychopharm Test 1 - Intro/Mood/MDD/Bipolar Flashcards
Classic Neurotransmission aka Anterograde
The stimulation of presynaptic neuron causes electrical impulses to be sent to the axon terminal. The electrical impulses are converted to chemical messengers & then stimulate the post synaptic neuron
** Communication between neurons is chemical (L to R; presynpatic to postsynaptic)
Retrograde Transmission
post synaptic neuron communicates with the presynaptic neuron. From R to Left.
Volume Transmission
occurs without a synpase at all - diffusion transmission
Ex. In prefrontal cortex - not a lot of dopamine reuptake pumps so dopamine will diffuse away to other dopamine receptors throughout the brain and stimulate them.
What are the 6 key neurotransmitters targeted by psychotropic drugs?
Serotonin
Norepinephrine
GABA
Dopamine
Glutamate
Acetylcholine
How are neurotransmitters recycled?
Via Transporters
Ex. SERT - reuptake of serotonin
DAT - reuptake of dopamine
NET - reuptake of NE
What are the 5 transduction cascades?
- Transmembrane
- G Protein Linked
- Enzymes
- Voltage Gated Ion Channels
- Ligand Gated
What psychotropic durgs use 12 transmembrane transporters?
SSRI/SNRI/DNRI
What psychotropic drugs use G protein linked transduction?
D2, 5HT2A, 5HT2C, 5HT1A, 5HT7
** 30% of meds we use like the D2 receptors
What psychotropic drugs target enzymes?
MAOI’s (mostly used in major depressive disorder)
What psychotropic drugs target Ligand Gated Channels?
5HT3 (benzos), NMDA, GABA-A neurosteroid sites
What psychotropic drugs target Voltage Gated ion channels
Anticonvulsants and Mood Stabilizers
Which two conduction cascades use the Agonist spectrum?
G protein linked and Ligand Gated (** all the receptor sites ones)
How do neurons adapt to medications?
Via upregulation/downregulaton & sensitizaton/desensitization
Upregulation
A mechanism for the increased or decreased sensitivity to agonists and antagonist drugs suggests that decreased exposure to an agonist results in an increase in the number of receptors (upregulation).
Ex. if you give somone a antagonist (receptor blocker) the receptors sense there is a decrease in the # of receptors and upregulated/make more receptors available. At the same time the receptors now become more sensitive, so there is sensization
Downregulation
Increased exposure to an agonist can result in a decrease in the number of receptors (downregulation). Body senses the receptors are stimulated too much decreases the number of receptors available. The overstimulation results in desensitization is as why you may need to increase a dose of medication
Epigenetic’s and gene expression
neurotransmission, drugs, and the ENVIRONMENT we are exposed to determined if certain genes in our body are expressed or silenced.
*Depending on what happens in a persons life (i.e sex abuse, trauma, dietary deficiencies, drugs etc) genes can change and be silenced or activated (in good an bad ways - like substance abuse, or coping mechanisms).
Full Agonist
Bind to receptor site and act just like the endogenous agonist made in the body that would normally bind to it. It produces the full response at the receptor site
Partial Agonist
binds to the receptor site that the endogenous agonist would normally bind to, but only generates a fraction of the response that the actual endogenous agonist would generate
Inverse agonist
binds to the same site as the endogenous agonist, but instead of agonizing it produces the opposite effect & causes a decrease in signaling at the receptor site
Antagonist
will bind to the receptor site, but not activate the receptor; instead it prevents/competes for the site and limits the amount of agonists that can bind to the site
Allosteric Modulators
bind to a different site than the endogenous agonist, but by binding to a different receptor site they alter the ability of the receptor to bind with it’s agonist. This can cause an increase or decrease in the ability of an agonist to bind to the receptor, or reduce the affects an agonist has when it does bind. Sometimes when allosteric modulators bind to a different site they can also activate the receptor on its own.
Pharmacokinetics
science of how drugs are absorbed distributed to tissues in the body and eliminated.
**Metabolism of CYP450 enzymes
Pharmacodynamics
How the drug that is metabolized/absorbed works in the body. (Mechanism of action of drug)
Ex. Agonists, Antagonists etc.
Therapeutic Index
area between a drugs lethal dose and effective dose. The wider the distance is the safer the drug tends to be.
Direct Agonists
directly bind to and activate receptor sites
Indirect Agonists
work to increase the # of neurotransmitters synthesized/released
OR
inhibit reuptake
What do MAOInhibitors do?
prevent the breakdown of neurotransmitters (dopamine, serotonin, NE)
What are the two types of allosteric modulators
postive allosteric modulators - boost what the neurotransmitter does
negative allosteric modulators - blocks what the neurotransmitter does