By Dillon Lim - Medicine Student @ Brasenose College, Oxford
Synapsins are a family of proteins, coded for by three genes in humans, that have important roles in controlling synaptic transmission – or the transduction of a signal between two neurons. Signals between nerves are most often carried by neurotransmitters – chemicals stored in phospholipid vesicles. A portion of these vesicles are ‘superprimed’ – they sit right on the presynaptic membrane and are the first to be released when an action potential reaches the presynaptic terminal. Many more vesicles sit further back, in what we call the reserve pool of vesicles. It is clear that synapsins have some role in maintaining the reserve pool, although different synapsins have different effects, and how they maintain the reserve pool is not exactly clear. Some people think that synapsins bind to each other to physically link vesi