Postsynaptic Marker Antibody Kit

The synapse is the junction at which neuronal communication is taking place; the information signal flows from the presynaptic neuron – or the transmitter – via its axon's end, to the postsynaptic cell – or the receiver – usually a neuron's dendrite but can also be the beginning of an adjacent neuron's axon, or any other excitable cell, such as a muscle cell.

At the synapse, communicating cells do not contact each other directly, but rather through the synaptic cleft. There, the presynaptic cell releases by exocytosis vesicles containing neurotransmitters and neuroactive peptides that bind to receptors at the membrane of the postsynaptic cell; this results in inhibition or excitation the target cell or an endocrinal signaling through the blood stream. Synaptic transmission is mostly chemical, but can also be entirely electrical^1-3.

Both the presynaptic membrane, where exocytosis takes place, and the synaptic vesicle membrane harbor a cluster of fusion proteins known as soluble N-ethylmaleimide–sensitive factor attachment receptors (SNAREs). The synaptic vesicle is released from the presynaptic cell when synaptobrevin, a type of SNARE that is expressed on the vesicle's membrane, binds syntaxin, SNAP-25 and Munc18 on the presynaptic membrane, thereby forming a tight connection which destabilizes the phospholipid arrangement of the membranes of both the vesicle and the cell. At the same time, influx of Ca²⁺ sensitizes the synaptic vesicle proteins known as synaptotagmins, and facilitates vesicle-membrane fusion. These processes culminate in the formation of a pore through which the content of the vesicle is spilled. Then, the SNARE complex dismounts and the vesicle is withdrawn backwards by endocytosis, to be recycled for additional rounds^4,5.