Synaptic cleft

A Synaptic cleft is the gap between the <a href="Presynaptic membrane">presynaptic membrane</a> and the <a href="Postsynaptic membrane">postsynaptic membrane</a> of <a href="Neuroned">neurones</a>, it is used to transfer a signal triggered by <a href="Action potentials">Action Potentials</a> through the body to initiate a response from a stimulus. The process begins when an Action Potential is initiated that exceeds threshold potential and <a href="Depolarise">depolarises</a> the presynaptic membrane causing the <a href="Voltage-gated Calcium channel">Voltage-gated Calcium channels</a> to open. This in turn causes an influx of <a href="Calcium">calcium</a> <a href="Ions">ions</a> and causes the Synaptic Vesicles to fuse with the Presynaptic membrane by <a _fcknotitle="true" href="Exocytosis">Exocytosis</a> allowing the <a href="Neurotransmitter">neurotransmitter</a> within the <a href="Vesicles">vesicles</a> diffuses across the Synaptic Cleft and bind to the receptors on the post-synaptic membrane. This causes the voltage gated ion channels to open, which depolarise the neurone. Drugs and hormones also act on receptors/ vesicles e.c.t in the cleft, which allows regulation of the signal. If there was no synaptic cleft, there would be no transport medium for the transfer of <a href="Neurotransmitter">neurotransmitters</a> from one neurone to the next.