This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: The Synapse A synapse, or synaptic cleft, is the gap that separates adjacent neurons or a neuron and a muscle. Transmission of an impulse across a synapse, from presynaptic cell to postsynaptic cell, is chemical. In chemical synapses, action potentials are transferred across the synapse by the diffusion of chemicals, as follows: 1. Calcium (Ca 2+ ) gates open. When an action potential reaches the end of an axon, the depolarization of the membrane causes gated channels to open that allow Ca 2+ to enter. 2. Synaptic vesicles release a neurotransmitter. The influx of Ca 2+ into the terminal end of the axon causes synaptic vesicles to merge with the presynaptic membrane, releasing a neurotransmitter into the synaptic cleft. 3. The neurotransmitter binds with postsynaptic receptors. The neurotransmitter diffuses across the synaptic cleft and binds with specialized protein receptors on the...
View Full Document
- Spring '10
- synaptic cleft, EPSP, IPSP, postsynaptic membrane