Midterm 1 - Psychopharmacology Flashcards
3 Things That Can Happen to a NT When It’s Released
- Diffuse Away
- Broken down with enzymes
- Re-Uptake
MAOs (A&B)
(Enzyme Deactivation)
Enzyme that destroys excess amounts of NT by inactivating it.
Not only do MAOs break apart NTs, they re-package them so they are ready to go to the synaptic cleft and be released again.
Ex. MAOb breaks down excess dopamine. Deprenyl is a dopamine agonist because it destroys MAOb (which breaks it down in the first place).
SNAP-25
A protein that, when activated by Ca2+, drags the vesicle to the appropriate docking location on the pre-synaptic membrane.
Pinocytosis
Reuptake (the process of the membrane pinching off and becomming a re-packaged vesicle).
Exocytosis
Release
2 Main Drug Classifications
- Agonist
- Antagonist
Agonist
A drug that increases the action of the synapse/NT.
3 Ways A Drug Can Be An Agonist
- It can mimic the NT.
- It can promote release of the NT.
- It can block re-uptake of the NT.
Amphetamine
Dopamine agonist (mimics dopamine).
SSRI
BLOCKS RE-UPTAKE
E.g., Prozac
Developed because other antidepressants on the market would block re-uptake of serotonin AND norepinephrine. But nor-epinephrine blockers are good for lethargic depressed people, but not anxious depressed. Therefore, SSRIs do away with the norepi component.
Antagonist
A drug that decreases the function of the NT at the synapse.
How Does an Antagonist Work?
BLOCKS the post-synaptic receptors (therefore NT can’t bind to the receptor and open the ion channel).
Anti-Psychotics
Dopamine antagonists.
3 Classes of NTs
- Quaternary Amine
- Monoamines
- Amino acids
Acetylcholine (ACh)
Quaternary Amine
Movement workhorse.
Main NT of the muscular system. Operates at neuromuscular junction.
2 Categories Monoamines
- Catecholeamines
- Indoleamines
Catecholeamines
(3)
Dopamine
Norepinephrine
Epinephrine
Indoleamines
Serotonin
Melatonin
Catecholeamine Synthesis Pathway
Mediated by enzymes.
- L-Tyrosine
- L-Dopamine
- Dopamine
- Norepinephrine
- Epinephrine
Indoleamine Synthesis Pathway
- L-Tryptophan
- 5-Hydroxytryptophan
- 5-Hydroxytryptamine (5-HT) *Serotonin
- Melatonin
Factories in the Midbrain That Make NTs
- Substantia Nigra - dopamine (nigrostriatal pathway)
- Raphe Nuclei - 5-HT
- Ventral Tegmental Area - dopamine (median forebrain bundle)
- Locus Ceruleus - Norepinephrine
Nigrostriatal Pathway
Dopamine pathway that starts in the substantia nigra and ends in the striatum (starts and stops movement).
Parkinson’s