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Brain Synapses and Neurotransmission - ( 3D Animation)

submitted by mauz15

1 decade 5 years 1 month 2 weeks ago

Synapses are specialized places between two nerve cells used for signal transmission between them. Neurotransmitters are chemicals released by neurons, that stimulate neighboring neurons and chemically pass electrical impulses to one another and throughout the nervous system.

[edit:](simplified) Structure of a synapse:

1. A presynaptic ending
2. a gap (synaptic cleft) between two neurons
3. A postsynaptic (receiving) ending

When a nerve signal reaches the end of an axon, it cannot go any further. So in most cases, the neuron triggers the release of a neurotransmitter (a chemical) that stimulates a new wave of electrical impulse in the next cell across the synapse. The first cell in the signal path is the presynaptic neuron. This one releases the neurotransmitter, while the postynaptic neuron (the second one) responds to it. The presynaptic neuron can synapse (communicate chemically) with center of the neuron, the axons ( a neuron's extensions) and dendrites ( smaller branched projections in a neuron).

Most synapses are chemical synapses, but a few cells use electrical synapses where electrical charged particles (ions) can diffuse directly from one cell to another, the disadvantage of this type of cell is that they cannot integrate information or make decisions. An advantage is that they can act faster.
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f14-13a-b_synapses_c.jpg