Which structure receives signals from other neurons?

• A. Axon
• B. Soma
• C. Axon terminals
• D. Dendrites

Answer: (D)

Signals from other neurons are received primarily by the dendrites. These tree-like extensions are studded with neurotransmitter receptors; when a presynaptic neuron releases neurotransmitters at a synapse, they bind these receptors and generate local, graded potentials. These inputs are collected and integrated as they sum across the dendritic tree and converge at the soma. If the combined input at the axon hillock reaches threshold, an action potential is fired down the axon to communicate with downstream neurons. The axon and its terminals are specialized for sending signals onward, while the soma coordinates integration and cellular maintenance. So viewed in terms of input, dendrites are the structures that receive signals from other neurons.