Term
| synthesis of 5-HT (2 steps) |
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Definition
1. tryptophan --> (via tryptophan hydroxylase) --> 5-HTP
2. 5-HTP --> (via AAAD) --> 5-HT |
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Term
| 5-HT is packaged into a synaptic vesicle via ______ |
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Definition
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Term
| Is 5-HT found all over the body or only in limited quantities? |
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Definition
| all over the body (plentiful) |
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Term
| Where must 5-HT be synthesized? |
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Definition
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Term
| Serotonin is talked about with ______ disorders |
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Definition
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Term
| Can tryptophan & serotonin cross the blood brain barrier? |
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Definition
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Term
| What is the rate limiting step in 5-HT synthesis? |
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Definition
| convert tryptophan to 5-HTP via tryptophan hydroxylase |
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Term
| 5-HTP is converted to 5-HT via ______ |
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Definition
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Term
| What is needed in order for a vesicle to take in 5-HT? |
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Definition
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Term
| Where does 5-HT synthesis & packaging occur? |
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Definition
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Term
| If most of the rate-limiting enzyme in 5-HT synthesis, ______, is inhibited, there is a rapid decrease in 5-HT levels |
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Definition
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Term
| If you inhibit most of the activity of AAAD, what happens to 5-HT levels? |
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Definition
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Term
| ______ is a good candidate for a regulatory point for 5-HT synthesis |
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Definition
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Term
| If extra 5-HT is added, what is the effect on tryptophan hydroxylase activity? |
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Definition
| no effect (therefore no end-product inhibition of this enzyme) |
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Term
| Are the co-factors for tryptophan hydroxylase typically in high or short supply? |
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Definition
| short supply (which could control tryptophan hydroxylase activity) |
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Term
| When O2 levels are artificially increased to high levels, what is the effect on 5-HT levels in the brain? |
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Definition
| there can be a dramatic increase |
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Term
| When action potential frequency increases, what happens to intracellular calcium? |
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Definition
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Term
| Intracellular calcium phosphorylates tryptophan hydroxylase, which ______ its affinity for the co-factor BH4 |
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Definition
| increases (leading to more 5-HT synthesis) |
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Term
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Definition
| transporter for specific serotonin reuptake |
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Term
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Definition
| chews up serotonin both intracellularly & extracellularly |
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Term
| 2 ways serotonin action can be terminated |
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Definition
1. serotonin is "chewed up" by MAO
2. reuptake into cell |
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Term
| 3 categories of 5-HT receptor effects |
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Definition
1. inhibitory, via metabotropic receptors (increase potassium current or decrease calcium current)
2. excitatory, via metabotropic receptors (decrease potassium current or increase calcium current)
3. excitatory, via ionotropic receptors (opens a cation channel that depolarizes the neuron) |
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Term
| main effect of 5-HT(1) receptors |
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Definition
inhibition of adenyl cyclase
*5-HT(1A) also opens potassium channels* |
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Term
| What is the source of serotonin in the brain? |
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Definition
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Term
| 2 disorders known to deal with serotonin |
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Definition
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Term
| Are there a huge number or only a few types of serotonin receptors? |
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Definition
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Term
| main effect of 5-HT(2) receptors |
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Definition
stimulation of phosphoinositide-specific phospholipase C
*5-HT(2A) also closes potassium channels* |
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Term
| What 5-HT receptor subtype is the ionotropic receptor? |
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Definition
5-HT(3)
*ligand-gated cation channel* |
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Term
| main effect of 5-HT(4) receptor |
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Definition
| stimulation of adenyl cyclase |
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Term
| main effect of 5-HT(5A) receptor |
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Definition
| inhibition of adenyl cyclase |
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Term
| Which receptor subtype isn't as uniform as the others (more of a hodge podge)? |
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Definition
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Term
| Serotonin modulates the ______ cycle |
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Definition
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Term
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Definition
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Term
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Definition
| affect norepinephrine transports |
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Term
| SERT & NET inhibitors (SNRIs) |
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Definition
| do the functions of both SERT & NET inhibitors |
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Term
| What is the idea behind legal drugs to affect serotonergic transmission? |
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Definition
| if you know the structure of the receptor, you can design a drug that goes in & does specifically what you want |
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Term
| 2 drugs that are 5-HT(2A) antagonists |
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Definition
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Term
| 2 drugs that are SERT inhibitors |
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Definition
1. MDMA (ecstasy)
2. cocaine |
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