Which part of the neuron is responsible for receiving signals from other neurons?

Question

Understanding the physiology of the neuron is important to determine where electrical signals start and end.

Answer 1

Hello,

Shannon gave a nice description of the different part of a traditional neuron.

Overall, the input zone of a neuron includes the dendrites *(with the axodendritic synapses) and for multipolar neurons, the soma (with axosomatic synapses). Structurally, it means that the membrane of the dendrites and the soma express many gated channels except the voltage gated sodium channels and the voltage gated potassium channels involved in the triggering and regeneration of the action potentials. However, all the other gated-channels are going ot play an important role to trigger the graded potentials (typically post synaptic potential or receptor potentials).

While the axon is the conducting zone, where action potentials are generated, you may have heard that we could have axoaxonic synapses involved in pre-synaptic inhibition or facilitation. This is when a neuron modulates an existing synapse by allowing more Ca++ to come inside the presynaptic terminal knob or less, thus modulating the number of synaptic vesicles that will fuse with the presynaptic membrane and release a neurotransmitter into the cleft. In those modulation situation, one could say that a neuron can receive signals at the most distal part of its axon.

Would be glad to help more if you wish!

severine

Answer 2

Major Parts of a Neuron

1. Cell Body (Soma) – The main part of the neuron that contains the nucleus (the cell’s control center). It directs all the activities of the neuron and keeps the cell alive. The cell body also processes incoming signals and decides whether to send a signal down the axon.
2. Dendrites – Short, branch-like extensions that spread out from the cell body. They receive signals or messages from other nerve cells acting like tiny antennas that pick up these incoming messages. A neuron can have many dendrites, forming a dendritic "tree" to collect lots of signals.
3. Axon – A long, thin fiber that extends from the cell body like a cable. It carries electrical signals away from the cell body toward other cells. Many axons are covered by a fatty layer called the myelin sheath, which insulates the axon and helps nerve signals travel faster and farther.
4. Axon Terminals (synaptic end bulbs) – The branched endings of the axon. These terminals connect to other neurons (or muscle cells) at special junctions called synapses, where they allow the neuron to pass along its signal. When an electrical signal reaches the axon terminals, they release chemical messengers (neurotransmitters) into the synapse. Those neurotransmitters carry the message across the tiny gap to the next neuron’s dendrites, passing the signal to the neighboring cell.