CNS I: intro Flashcards
Six steps of neurochemical transmission.
- Transport and synthesis
- Storage (in vesicles)
- Release
- Receptor activation
- Reuptake
- Degradation
What four things are necessary for complete neurotransmitter release.
action potential, Ca2+ influx, vesicle docking, exocytosis
What ion mediates an IPSP?
Cl-
Can an IPSP occur when the cell is at rest? Why?
no, only when it’s depolarized because neuronal resting potential is right near the Cl- equilibrium potential
Name the neurotransmitter that corresponds with the action of each of the following reuptake transporters: GAT(1-4), DAT, SERT, NET, EAAT(1-5)
GAT - GABA DAT - dopamine SERT - 5-HT NET - norepi EAAT - glutamate
Name the neurotransmitter (or class of transmitters) transported into vesicles by the following. Which one localizes to non-neuronal vesicles instead of synaptic vesicles? VGAT, VMAT1, VMAT2, VAChT, VGluT1
VGAT - GABA, glycine VMAT1&2 - monoamines VAChT - ACh VGluT1 - glutamate (VMAT1 is in non-neuronal vesicles)
<p>
| Which neurotransmitters don't undergo reuptake directly into the presynaptic neuron? How are they recycled?</p>
<p>
glutamate; uptake into glial cells and metabolized into glutamine, which is then transported back to the neuron</p>
<p>
ACh; degradation by acetylcholinesterase in the cleft</p>
What’s the difference between direct and indirect receptor types?
Direct - ion channels
Indirect - GPCRs
Direct or indirect receptor: nicotinic ACh, muscarinic ACh, NMDA, GABA-A, GABA-B, 5HT3, all catechol receptors, all histamine, all other 5-HT
direct - nicotinic, NMDA, GABA-A, 5HT3
indirect - muscarinic, GABA-B, all catechol, histamine, all other 5-HT
What are the three steps along the signaling cascade where amplification occurs with GPCRs?
- receptor/G-protein
- 2nd messenger production
- protein kinase phosphorylation of target proteins
Continued or repeated exposure to the same drug produces a diminished response.
desensitization
Some neurotransmitter receptors require a second agonist to bind to a separate allosteric site in order to activated.
coactivation
Other compounds may increase the response to an agonist by binding to an allosteric site.
potentiation
Decreased response after prolonged exposure to a drug or agonist. Results from decrease in receptor number.
downregulation
Increased response after prolonged exposure to a drug or antagonist. Results from increase in receptor number.
upregulation
