The presynaptic terminal, more commonly referred to as the axon terminal, releases neurotransmitters into the synaptic cleft in order to pass a signal onto the postsynaptic neuron.
Upon depolarization of the membrane at the dendrite, the action potential is transmitted through the presynaptic neuron and down the axon towards the presynaptic terminal. Depolarization at the axon terminal causes an influx of calcium through ion channels.
Presynaptic terminals contain numerous docked vesicles that are filled with neurotransmitters. This area is known as the synaptic active zone. Due to the high levels of calcium within the cell after depolarization, these docked vesicles release the stored neurotransmitters into the synaptic cleft by fusing their membranes with the cell membrane.
The released neurotransmitters bind to receptors on the post-synaptic neuron, thereby successfully passing the signal onto the postsynaptic cell.
The synaptic active zone contains distinct proteins such as piccolo, bassoon, CASK, SNAREs, SNAP25, VAMP, and syntaxin. Immunostaining of the synaptic active zone utilizes presynaptic markers specific to those unique proteins. We are dedicated to developing cutting edge presynaptic markers to aid in the study of signal transduction in neuroscience, including monoclonal antibodies, polyclonal antibodies, and antibody conjugates.