Synaptic Transmission

Question 1

How does synaptic transmission work?

Answer 1

The cell’s electrical impulse/ action potential starts as a small electrical impulses generated at the axon hillock, but once the message reaches the axon terminal it turns into a chemical message. When the impulse reaches the axon terminal, the neuron can pass its chemical message across the synaptic gap/ cleft.
Each neuron is responsible for producing a certain neurotransmitter/ chemical, and when the action potential reaches the axon terminal, calcium channels open and flood they terminal button with calcium ions. Vesicles containing the neurotransmitter substance will then be released and travel and travel down the outer membrane of the terminal button, where the casing of the vesicle will fuse with the membrane. This allows the neurotransmitter to be released from its vesicles into the synaptic gap/ cleft.

Question 2

What is the synaptic cleft?

Answer 2

• the space between two adjacent neurons

Question 3

What is the pre-synaptic neuron?

Answer 3

• The neuron sending the message is referred to as the pre-synaptic neuron

Question 4

What is the post-synaptic neuron?

Answer 4

• The one receiving the message is the post-synaptic neuron.

Question 5

What do the receptors on the post-synaptic neuron do?

Answer 5

The receptors on the postsynaptic neuron are designed to bind to a specific neurotransmitter, and when they detect it the neurotransmitter molecule will then be absorbed by the postsynaptic neuron.

Question 6

What is reuptake?

Answer 6

• Any neurotransmitter molecules that have not been absorbed by the receptors of the postsynaptic neuron will be destroyed by enzymes in the synaptic cleft or will be reabsorbed by the presynaptic neuron; this is called reuptake.

Question 7

What happens to reabsorbed enzymes?

Answer 7

• Reabsorbed enzymes are destroyed by enzymes in the neuron in order to ‘turn off’ the neuron in preparation for a future action potential