Ribbon synapse

Ribbon synapse is a type of synapse that is specialized for rapid and sustained neurotransmitter release. It is found in various parts of the body, particularly in the sensory systems such as the retina and the inner ear.

Structure

The ribbon synapse is named for its distinctive structure, which features a plate-like or ribbon-like presynaptic structure that is tethered to the active zone of the synapse. This "ribbon" is composed of a protein called RIBEYE. The ribbon is surrounded by a halo of vesicles, which are filled with neurotransmitters.

Function

The primary function of the ribbon synapse is to facilitate the rapid and sustained release of neurotransmitters. This is achieved through the unique structure of the ribbon, which allows a large number of vesicles to be primed and ready for release at any given time. This is particularly important in sensory systems, where rapid and continuous signal transmission is necessary.

In the retina, for example, ribbon synapses are found in the photoreceptor cells, where they play a crucial role in transmitting visual information to the brain. In the inner ear, they are found in the hair cells, where they are involved in transmitting auditory information.

Clinical significance

Abnormalities in the structure or function of ribbon synapses can lead to various health problems. For example, mutations in the RIBEYE gene can cause congenital stationary night blindness, a condition characterized by difficulty seeing in low light. Similarly, damage to the ribbon synapses in the inner ear can lead to hearing loss.

See also

• Synapse
• Neurotransmitter
• Retina
• Inner ear