1 Roadmap for Quality Measurement in the Traditional Medicare Fee-for-Service Program [PDF, 3MB]. 2  Roadmap for Implementing Value Driven Healthcare in the Traditional Medicare Fee-for-Service Program [PDF, 3MB]. 3  Medicare Resource Use Measurement Plan [PDF, 3MB].
When a nerve signal, or impulse, reaches the ends of its axon, it has traveled as an action potential, or a pulse of electricity. However, there is no cellular continuity between one neuron and the next; there is a gap called synapse.
In a typical chemical synapse between two neurons, the neuron from which the nerve impulse arrives is called the presynaptic neuron. The neuron to which the neurotransmitters (chemical messengers) bind is called the postsynaptic neuron. A presynaptic neuron has several specialized structures that distinguish it from a postsynaptic neuron.