Neural Backpropagation - Mechanism

Mechanism

When a neuron fires an action potential, it is initiated at the axon hillock. An action potential spreads down the axon because of the gating properties of voltage-gated sodium channels and voltage-gated potassium channels. However, the cell body or soma can also become depolarized when an action potential is initiated, and this depolarization can spread out to the dendritic tree where there are voltage-gated calcium channels. Voltage-gated calcium channels can then lead to a propagating (most of the time) dendritic action potential. EPSPs from synaptic activation are not large enough to activate the dendritic voltage-gated calcium channels (usually on the order of a couple milliamperes each) so backpropagation is believed to happen only when the cell is activated to fire an action potential.

Read more about this topic:  Neural Backpropagation

Famous quotes containing the word mechanism:

    The two elements the traveler first captures in the big city are extrahuman architecture and furious rhythm. Geometry and anguish. At first glance, the rhythm may be confused with gaiety, but when you look more closely at the mechanism of social life and the painful slavery of both men and machines, you see that it is nothing but a kind of typical, empty anguish that makes even crime and gangs forgivable means of escape.
    Federico García Lorca (1898–1936)

    I’ve never known a Philadelphian who wasn’t a downright “character;” possibly a defense mechanism resulting from the dullness of their native habitat.
    Anita Loos (1888–1981)

    Life is an offensive, directed against the repetitious mechanism of the Universe.
    Alfred North Whitehead (1861–1947)