Special Tactics Advanced Skills Training, Hurlburt Field, Fla. Advanced skills training is a 12-to-15-month program for newly assigned combat controller operators. AST produces mission-ready operators for the Air Force and U.S. Special Operations Command. The AST schedule is broken down into four phases: water, ground, employment and full mission profile.
Saltatory Conduction. As in un-myelinated axons, the first action potential in myelinated axons takes place at the initial segment of an axon and is generated by a threshold stimulus from the dendrites and cell body. Subsequent action potentials occur at the nodes of Ranvier, where the Na+ voltage-gated channels are located. Therefore, when nerve impulses travel down a myelinated axon, they appear to jump from node to node - in a process called saltatory conduction. Each nodal action potential is triggered by a threshold stimulus created by passive current from the previous node.
When a nerve impulse reaches the synapse at the end of a neuron, it cannot pass directly to the next one. Instead, it triggers the neuron to release a chemical neurotransmitter. The neurotransmitter drifts across the gap between the two neurons. On reaching the other side, it fits into a tailor-made receptor on the surface of the target neuron, like a key in a lock. This docking process converts the chemical signal back into an electrical nerve impulse.