PLease explain how the process that allows nerve cells to communicat with adjacent cells?

Question

what is the chemical messenger being used?
where are they made?
How does the signal reach adjacent cells, and are there any mechanisms to turn off the signal and or conserve the messenger molecule?

i know im asking alot, but thanks for your help

Answer 1

nerve cells are electrically excitable cells in the nervous system that function to process and transmit information

Neurons are typically composed of a soma, or cell body, a dendritic tree and an axon. The majority of vertebrate neurons receive input on the cell body and dendritic tree, and transmit output via the axon.

Neurons communicate with one another via synapses, where the axon terminal of one cell impinges upon a dendrite or soma of another (or less commonly to an axon).Neurons communicate via chemical and electrical synapses, in a process known as synaptic transmission. The fundamental process that triggers synaptic transmission is the action potential, a propagating electrical signal that is generated by exploiting the electrically excitable membrane of the neuron.

Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a neuron and another cell.

It is synthesized endogenously, that is, within the presynaptic neuron;
It is available in sufficient quantity in the presynaptic neuron to exert an effect on the postsynaptic neuron;
Externally administered, it must mimic the endogenously-released substance; and
A biochemical mechanism for inactivation must be present.

Examples of neurotransmitters:
acetylcholine
monoamines (norepinephrine NA, dopamine DA & serotonin 5-HT)

Answer 2

The chemical messengers used depends on what part or which nervous system you're talking about.

Usually, however, it is acetylcholine (ACh) or norepinephrine, which are released as a result of higer calcium concentrations at the axon terminals. The neurotransmitters are released across synaptic clefts (regions between two neurons).

The synthesis of ACh:
http://www.sanger.ac.uk/PostGenomics/genetrap/IGTC_MAPP/metabolic_process-GenMAPP/Mm_Acetylcholine_Synthesis/Mm_Acetylcholine_Synthesis.htm

The signal reaches adjacent cells by propagation (like dominos-from one to another) until the stimulus that started the whole process (a graded or action potential) stops.
http://web.indstate.edu/thcme/mwking/nerves.html#ach

Answer 3

The chemical messenger being used is called a neurotransmitter.

Neurotransmitters can be small molecule neurotransmitters or neuropeptides. Small molecule neurotransmitters are synthesized in the axon terminal and stored in vesicles. Neuropeptides are synthesized in the soma (cell body) and transported to the axon terminal in large dense core vesicles.

Neurotransmitters are released into the synaptic cleft by exocytosis and they act on the postsynaptic cell because the postsynaptic cell has a receptor for the transmitter that was released.

The transmitters can either be taken back up into the presynaptic terminal or degraded in the synaptic cleft by enzymes.

Next time read your book.