Synaptic Transmission

Question 1

What are the steps for synaptic transmission?

Answer 1

1. Action potential arrives, opens up Ca2+ channels and Ca2+ flows into the axon terminal
2. Ca2+ causes synaptic vesicles to fuse with the presynaptic membrane and release neurotransmitters into the synaptic cleft
3. Neurotransmitters bind to receptors on the post-synaptic cell
4. EPSP or IPSP occurs
5. Synaptic Transmission is terminated by neurotransmitter reuptake or neurotransmitter degradation

Question 2

What is Ligand Receptor binding?

Answer 2

It is the generic name for a binding site that essentially acts like a lock and key (specific interaction)

Question 3

What is an example of a Ligand Receptor?

Answer 3

Neurotransmitter receptor

Question 4

What are the two types of neurotransmitter receptors?

Answer 4

Inotropic receptor and metabotropic receptor

Question 5

Inotropic receptor

Answer 5

• It’s both a NT receptor and an ion channel
• when a NT binds to it an ion channel opens
• fast acting
• aka ligand gated ion channels

Question 6

metabotropic receptor

Answer 6

• not an ion channel
• When a NT binds to this receptor, a G-protein is activated
• The activated G-protein opens ion channels
• aka G-protein coupled receptors
• Slower to activate and deactivate, resulting in longer post synaptic potentials

Question 7

In synaptic transmission, ____ influx leads to EPSP while ____ influx leads to IPSP

Answer 7

• Na+
• Cl-

Question 8

When it comes to terminating synaptic transmissions, neurotransmitters can either be _________ or ______

Answer 8

• Enzymatic degradation (a specific enzyme changes the structure of the neurotransmitter so it is not recognized by the receptor)
• reuptake (transported back into the pre-synaptic cell)