Neurotransmitters

Neurotransmitters, also named as chemical transmitter, are a great variety of chemical agents released by neurons to stimulate neighbouring neurons. Through this way, impulses to are transferred from one cell to the next throughout the nervous system. The synapse is the site where neurons meet, consisting of the axon terminal of one cell and the dendrite of the next. A synaptic cleft is a microscopic gap existing between the neurons. When arriving at the axon terminal of one neuron, the nerve impulse would elicit the presynaptic membrane to release a chemical substance. The release of the chemical substance is stimulated by the electrical activity of the neuron. The chemical substance can be transported at extremely high speed to the postsynaptic membrane of the adjoining neuron. It will take only milliseconds for the chemical substance to transfer across the synaptic cleft. The chemical substances like this are called neurotransmitters. The identified neurotransmitters include dopamine, norepinephrine, acetylcholine, and serotonin.