synapse

American  

[sin-aps, si-naps] / ˈsɪn æps, sɪˈnæps /

noun

1. a region where nerve impulses are transmitted and received, encompassing the axon terminal of a neuron that releases neurotransmitters in response to an impulse, an extremely small gap across which the neurotransmitters travel, and the adjacent membrane of an axon, dendrite, or muscle or gland cell with the appropriate receptor molecules for picking up the neurotransmitters.

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verb (used without object)

synapsed, synapsing

1. Cell Biology, Physiology. to form a synapse or a synapsis.

synapse British  

/ ˈsaɪnæps /

noun

1. the point at which a nerve impulse is relayed from the terminal portion of an axon to the dendrites of an adjacent neuron

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synapse Scientific  

/ sĭn′ăps′ /

1. The small junction across which a nerve impulse passes from one nerve cell to another nerve cell, a muscle cell, or a gland cell. The synapse consists of the synaptic terminal, or presynaptic ending, of a sending neuron, a postsynaptic ending of the receiving cell that contains receptor sites, and the space between them (the synaptic cleft). The synaptic terminal contains neurotransmitters and cell organelles including mitochondria. An electrical impulse in the sending neuron triggers the migration of vesicles containing neurotransmitters toward the membrane of the synaptic terminal. The vesicle membrane fuses with the presynaptic membrane, and the neurotransmitters are released into the synaptic cleft and bind to receptors of the connecting cell where they excite or inhibit electrical impulses.

2. See also neurotransmitter

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synapse Cultural  

1. A gap between two nerve cells. Nerve signals are sent across the gap by neurotransmitters.

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Other Word Forms

• synaptic
  adjective
• synaptical
  adjective
• synaptically
  adverb

Etymology

Origin of synapse

1895–1900; back formation from synapses, plural of synapsis

Explanation

A synapse is the tiny gap across which a nerve cell, or neuron, can send an impulse to another neuron. When all your synapses are firing, you're focused and your mind feels electric. Synapse is not an old word. It was coined in an 1897 physiology textbook, from the Greek sun- "together" + haptein "join" — it’s the space across which nerve cells can "join together" to communicate from one cell to the next or from a neuron to a muscle. When a chemical or electrical impulse makes that tiny leap across one of your synapses, which you have throughout your nervous system, your body can do what your brain tells it to do.

Example Sentences

See Examples For:

synapse synapsed synapsing

When the body faces infection or cancer, cytotoxic T lymphocytes bind tightly to their target and form the immune synapse.

From Science Daily ● Apr. 30, 2026

Somewhere deep in the limbic system, a synapse fires like a flare, tracing the old circuitry of migration and memory — that annual pull toward the wide-open deserts of the American Southwest.

From Los Angeles Times ● Feb. 5, 2026

Taken together, the findings suggest that both amyloid beta and inflammation may drive synapse loss through the same biological mechanism.

From Science Daily ● Jan. 26, 2026

The protein fragment C4d attached strongly enough to raise the possibility that it could contribute directly to synapse loss.

From Science Daily ● Jan. 26, 2026

At the terminal on the far end, signals are converted back into chemical messengers, called neurotransmitters, for the short voyage across the synapse to the dendrites of the next neuron.

From "Phineas Gage" by John Fleischman

When synapsed, homologous chromosomes undergo reciprocal physical exchanges at their arms in a process called homologous recombination, or more simply, “crossing over.”

From Textbooks ● Jun. 9, 2022

About 90 percent of the afferent neurons carry information from inner hair cells, with each hair cell synapsing with 10 or so neurons.

From Textbooks ● Jun. 9, 2022

Every time he does a show, he admits, he feels a shiver synapsing down his spine.

From Time Magazine Archive