Intermediate
Technical
IVT
synaptic cleft
The narrow gap between the presynaptic and postsynaptic neurons at a synapse.
Full Definition
The synaptic cleft is the extracellular space between the presynaptic axon terminal and the postsynaptic membrane at a chemical synapse. This gap, typically 20-40 nanometers wide, is where neurotransmitters are released and must diffuse to reach receptors on the postsynaptic cell. The width and properties of the synaptic cleft influence the speed and efficiency of synaptic transmission.
In Context
- "Neurotransmitters must cross the synaptic cleft to activate postsynaptic receptors." — neurobiology textbook
- "Electron microscopy revealed structural abnormalities in the synaptic cleft." — ultrastructural study
Also known as
synaptic gap
Don't confuse with
synaptic vesicle