Ch. 12 steps involved in synaptic transmission in an excitatory cholinergic synapse

What is a neurotransmitter?

is a chemical messenger that transmits signals across a synapse from one neuron to another or to a target cell (such as a muscle cell).

What is the first step in synaptic transmission in an excitatory cholinergic synapse?

The arrival of action potentials at the axon terminal opens voltage-gated calcium channels.

What happens after calcium enters the neuron in an excitatory cholinergic synapse? (2)

Calcium triggers exocytosis of synaptic vesicles, releasing acetylcholine (ACh).

What happens to empty vesicles after neurotransmitter release in an excitatory cholinergic synapse? (3)

Empty vesicles are pulled back into the cytoplasm to be refilled with ACh.

How does acetylcholine (ACh) affect the postsynaptic neuron? (4)

ACh diffuses across the synaptic cleft and binds to ligand-gated channels on the postsynaptic neuron, allowing Na+ to enter the cell.

What happens when Na+ enters the postsynaptic neuron in an excitatory cholinergic synapse? (5)

The Na+ spreads along the inside of the plasma membrane, depolarizing it and producing a local voltage shift (postsynaptic potential).

If strong and persistent enough, this leads to the opening of voltage-gated ion channels, triggering a new wave of action potentials.