synaptic cleft

(noun)

A small space between neurons.

Related Terms

Examples of synaptic cleft in the following topics:

  • Peripheral Motor Endings

    • This influx of Ca2+ causes neurotransmitter-containing vesicles to dock and fuse to the presynaptic neuron's cell membrane, which results in the emptying of the vesicle's contents (acetylcholine) into the synaptic cleft; this process is known as exocytosis.
    • Acetylcholine diffuses into the synaptic cleft and binds to the nicotinic acetylcholine receptors located on the motor end plate.
    • Detailed view of a neuromuscular junction: 1) Presynaptic terminal; 2) Sarcolemma; 3) Synaptic vesicle; 4) Nicotinic acetylcholine receptor; 5) Mitochondrion.

  • The Synapse

    • The presynaptic neuron contains a chemical called a neurotransmitter that is packaged into synaptic vesicles clustered beneath the membrane in the axon terminal.
    • The neurotransmitter is released into and diffuses across the synaptic cleft, where it binds to specific receptors in the membrane on the postsynaptic side of the synapse.
    • A: Neuron (Presynaptic) B: Neuron (Postsynaptic)MitochondriaSynaptic vesicle full of neurotransmitterAutoreceptorSynaptic cleftNeurotransmitter receptorCalcium ChannelFused vesicle releasing neurotransmitterNeurotransmitter re-uptake pump

  • Types of Neurotransmitters by Function

    • Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane in the axon terminal on the presynaptic side of a synapse.
    • They are released into and diffuse across the synaptic cleft, where they bind to specific receptors in the membrane on the postsynaptic side of the synapse.
    • Once released, acetylcholine binds to post-synaptic receptors and is degraded by acetylcholinesterase.

  • Cholinergic Neurons and Receptors

    • This enzyme is abundant in the synaptic cleft, and its role in rapidly clearing free acetylcholine from the synapse is essential for proper muscle function.

  • Premature Ejaculation

    • Therefore, it is perceived that low level of serotonin in the synaptic cleft in these specific areas in the brain could cause premature ejaculation.

  • Cleft Palate and Lip

    • Cleft lip and cleft palate are variations of a type of clefting congenital deformity caused by abnormal facial development during gestation.
    • Approximately 1 in 700 children are born with a cleft lip and/or a cleft palate.
    • If the cleft does not affect the palate structure of the mouth, it is referred to as cleft lip .
    • Cleft lip is formed in the top of the lip as either a small gap or an indentation in the lip (partial or incomplete cleft) or it continues into the nose (complete cleft).
    • The soft palate is cleft as well.

  • Vulva

    • The cleft between the labia majora is called the pudendal cleft, or cleft of Venus, and it contains and protects the other, more delicate structures of the vulva.
    • The labia majora meet again at the perineum, a flat area between the pudendal cleft and the anus.
    • Often the clitoral hood is only partially hidden inside of the pudendal cleft.

  • Congenital Defects

    • An example of a birth defect is cleft palate .

  • Neuroglia of the Central Nervous System

    • Their numerous radiating processes cling to neurons and their synaptic endings.
    • They also regulate the external chemical environment of neurons by removing excess ions and recycling neurotransmitters released during synaptic transmission.

  • Adrenal Medulla

    • Chromaffin cells are the neuroendocrine cells found in the medulla, they are modified post-synaptic sympathetic neurons that receive sympathetic input.