Primary Somatosenory Cortex
Neurotransmitter Release At Cholinergic Synapses
- Cholinergic synapses are chemical synapses that that use acetylcholine molecules as the neurotransmitter.
- Synaptic transmission begins when an action potential or electrochemical impulse reaches the synaptic knob of a presynaptic neuron.
- Ca2+ channels open in response, and Ca2+ ions diffuse into the synaptic knob. The influx of Ca2+ causes many of the synaptic vesicles to fuse with the presynaptic membrane.
- As the vesicles fuse, thousands of stored acetylcholine (or ACh) transmitter molecules are released into the synaptic cleft.
- A few of these molecules diffuse across the synaptic cleft and bind to the acetylcholine receptors that are embedded in the membrane of the postsynaptic neuron.