Signal transmission at chemical synapses involves several steps:
1. Action Potential Arrival: An action potential travels down the axon of the presynaptic neuron to the synaptic terminal. 2. Neurotransmitter Release: Voltage-gated calcium channels open in response to the action potential, allowing calcium ions to enter the presynaptic terminal. This influx of calcium causes synaptic vesicles to fuse with the presynaptic membrane and release neurotransmitters into the synaptic cleft. 3. Neurotransmitter Binding: Neurotransmitters diffuse across the synaptic cleft and bind to specific receptors on the postsynaptic membrane. 4. Post-Synaptic Response: The binding of neurotransmitters to receptors induces a response in the postsynaptic neuron, which can be either excitatory or inhibitory, depending on the type of receptor and neurotransmitter involved.
