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.
verb (used without object),syn·apsed,syn·aps·ing.
Cell Biology, Physiology. to form a synapse or a synapsis.
"junction between two nerve cells," 1899, from Greek synapsis "conjunction," from synaptein "to clasp," from syn- "together" (see syn-) + haptein "to fasten." Related to apse. Introduced by English physiologist Sir Michael Foster (1836-1907) at the suggestion of English classical scholar Arthur Woollgar Verral (1851-1912).
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. See also neurotransmitter.