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
Median Forebrain Bundle (MFB)
Dopamine pathway that starts in the midbrain (VTA) and goes to the forebrain (PFC).
***Thoughts and emotions. Thought disorders.
***Schizophrenia and bipolar (mania = too much dopamine).
Without dopamine in PFC, you lose executive functioning.
Norepinephrine
- Locus Ceruleus
- Level of game
- Over-productivity = anxiety
- Role in controlling brain wave functions when you sleep (wake up when norepi is released).
- Will increase when in danger