Dendrites

In biology, a dendrite is a slender, typically branched projection of a nerve cell, or neuron, which conducts the electrical stimulation received from other cells to and from the cell body, or soma, of the neuron from which it projects. These stimulations arrive through synapses, which are located at various points throughout the dendritic arbor. Dendrites were once believed to merely convey stimulation passively, without action potentials and without activation of voltage-gated ion channels. In such dendrites the voltage change that results from stimulation at a synapse will depend on the passive cable properties of the dendrite. In excitable dendrites, voltage gated ion channels help propagate excitatory synaptic stimulation whether or not an action potential is present in the axon. Additionally, action potentials can propagate back into the dendrites once initiated in the axon in most neurons. This backpropagating action potential is mediated by the activation of voltage-gated ion channels and can interact with synaptic input to alter the synaptic activity.

The structure and branching of a neuron's dendrites strongly influences how it integrates the input from many other neurons, particularly those that input only weakly. This integration is both "temporal" -- involving the summation of stimuli that arrive in rapid succession -- as well as "spatial" -- entailing the aggregation of excitatory and inhibitory inputs from separate branches or "arbors."

The term "dendrite" comes from the Greek word dendron, meaning "tree".