How does a signal travel through a neuron?

Answer 1

Nerves communicate at specialized cell junctions known as synapses. In response to some stimuli, in many cases an action potential, the pre-synaptic nerve releases signal molecules into the space between the two cells (the synaptic cleft). The signaling molecule is then bound by a receptor on the post-synaptic neuron.

In this fashion "instructions" can be communicated between neurons. Generally binding of the messenger signal leads to the opening of an ion channel in the post-synaptic nerve causing that nerve to either become more or less excited. In the case of more excited the post-synaptic neuron will approach being able to fire its own action potential if it is excited enough.

Answer 2

1. From a signal transmitted from another neuron

2. From another source of electrical stimulation significant enough to cause depolarization

3. From a chemical imbalance in the cell's environment

Answer 3

A neuron is a nerve cell that is the basic building block of the nervous system. Neurons are similar to other cells in the human body in a number of ways, but there is one key difference between neurons and other cells. Neurons are specialized to transmit information throughout the body.

These highly specialized nerve cells are responsible for communicating information in both chemical and electrical forms. There are also several different types of neurons responsible for different tasks in the human body.

Sensory neurons carry information from the sensory receptor cells throughout the body to the brain. Motor neurons transmit information from the brain to the muscles of the body. Interneurons are responsible for communicating information between different neurons in the body.

Answer 4

This is going to be an abbreviated explanation as a complete explanation would require a more in-depth background on how neurons operate.

Most neurons have 3 major areas: The axon, the soma, and dendrites. The soma of a neuron is the main compartment of the cell and usually contains the nucleus as well as other basic cell machinery. The basic layout is that the axon of one neuron comes close to contacting the dendrites of other neurons. The area where these two almost meet is called the synaptic cleft. Usually an axon has a number of little "fingers" that contact multiple dendrites, often from multiple neurons. Dendrites themselves are like a tree and branch from the soma of the cell. In fact, it is called a "dendritic arbor". This is a sort of generic view. To be clear, there are a number of different types of neurons and each kind has variations in the layout. Some have very big, branchy dendrites, some have only one long dendrite. Most branch, however.

When an action potential is produced by a neuron, it sends a charge along the axon to the ends of the axon, called the axon terminals. When this charge arrives at the axon terminals, small "bubbles" inside the axon terminals, called neurotransmitter vesicles, merge with the cell's membrane. When it merges, the neurotransmitters (chemicals inside the vesicles) are released outside the axon terminal. Those neurotransmitters cause a reaction inside the dendrite nearby.

Depending on the type of neurotransmitter, a number of "channels" are either opened or closed in the dendrite in the area where it received the neurotransmitters. These channels are like holes in the cell membrane that only let certain things in or out. There are a variety of different channel types and they respond differently to different neurotransmitters. The primary types of channels are potassium (K+), sodium (Na+), calcium (Ca2+) and chlorine (Cl-). There are many variant of each of these. When a potassium channel is opened, for example, it allows potassium ions to pass either into the neuron or out of the neuron.

When the neurotransmitters cause the channels to open (remember, some channels open, some close, depending on the channel type and the neurotransmitter type) the ions associated with that channel type either move in our out of the cell. If the neurotransmitter causes the channel to close, those types ions will not pass through it. Some signals are inhibiting and actually work to prevent a neuron from building an action potential, but others will help it build an action potential.

In the generic situation of the latter case, sodium channels open up allowing sodium ions (which are in a higher concentration outside the cell) into the cell and this, locally, builds up a relative charge inside the dendrite. This charge then propagates along the dendrite towards the soma of the cell.

If the voltage reaches a certain threshold (this threshold differs by neuron type), then the soma produces and action potential which is then sent down the axon of the neuron. To achieve this threshold, it usually takes the input from several neurons occurring within a short timespan.

There are a lot of details that have been generalized or glossed over here. Whether or not an action potential is produced is very complex to model and requires a great deal of mathematics to reproduce accurately.

Answer 5

A signal travels through a neuron via electrical impulses and chemical signals. When a neuron is stimulated, it generates an action potential that travels along the length of the neuron's axon. At the end of the axon, neurotransmitters are released into the synapse, where they can then bind to receptors on the next neuron and continue the signal transmission.

Answer 6

Neurons have dendrites, which receive input, a soma or cell body, and axons that carry the neutral message to other cells.

Answer 7

Please see related links below.

Answer 8

Action potential