Types
At any given moment, a neuron may be receiving postsynaptic potentials from thousands of other neurons. Whether or not threshold is reached, and an action potential generated, is dependent upon the spatial (from multiple neurons) and temporal summation (from a single neuron) of all inputs at that moment. In addition, the summation of excitatory and inhibitory influences will modulate the outcome. The closer a synapse is to the cell body of a neuron, the greater the influence on the final summation. This is due to the fact that the postsynaptic potentials travel through the unmyelinated dendrites to the axon hillock, where they are combined in summation. Because dendrites are unmyelinated the sustained membrane potential decreases increasingly over the amount of distance travelled.
Read more about this topic: Summation (neurophysiology)
Famous quotes containing the word types:
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—Michael Blankfort. Lewis Milestone. Johnson (Reginald Gardner)
“Science is intimately integrated with the whole social structure and cultural tradition. They mutually support one other—only in certain types of society can science flourish, and conversely without a continuous and healthy development and application of science such a society cannot function properly.”
—Talcott Parsons (1902–1979)
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—Henry David Thoreau (1817–1862)